Question 1

A 26-year-old man comes to the office due to several months of dysuria and increased urinary frequency.  He also has blood in his urine at the end of urination.  A month ago, he finished 7 days of oral antibiotics for urinary tract infection, but his symptoms did not improve.  The patient has no other medical issues and takes no medications.  He emigrated from Ghana 2 years ago and works in a chemical fertilizer factory.  The patient smokes a pack of cigarettes daily and occasionally drinks alcohol.  He is married and has no children.  Temperature is 37.2 C (99 F), blood pressure is 130/80 mm Hg, and pulse is 76/min.  No abdominal mass or suprapubic or costovertebral angle tenderness is present.  Genital examination is normal.  Laboratory results are as follows:  A dipstick urinalysis shows 1+ blood but is otherwise negative.  Which of the following is the best next step to establish the diagnosis in this patient?

Accepted Answer

Explanation: This young patient who emigrated from Ghana has urinary symptoms, terminal hematuria, and peripheral eosinophilia, raising suspicion for urinary schistosomiasis. Schistosomiasis is a parasitic blood fluke infection that affects more than 200 million people worldwide. The greatest prevalence is in sub-Saharan Africa. Schistosomes live in specific types of freshwater snails, and humans in endemic areas are often infected as children when bathing in contaminated freshwater. Although five different species of schistosomes cause human infections, urinary schistosomiasis is typically due to Schistosoma haematobium. Patients with urinary schistosomiasis are usually asymptomatic initially, but chronic infections are marked by bladder inflammation and scarring with resultant dysuria, urinary frequency, and terminal hematuria. Peripheral eosinophilia is seen in 30%-60% of cases, and anemia is common due to chronic blood loss. Diagnosis requires the identification of eggs using urine sediment microscopy. Treatment with praziquantel is usually curative. (Choice A) Chronic urinary schistosomiasis can cause bladder wall irregularities and ureter scarring, which may be seen on abdominal ultrasonography; however, these findings would only be suggestive of schistosomiasis, not diagnostic. This patient requires the identification of eggs by microscopic examination of urine. (Choice B) Chronic schistosomiasis can be associated with bladder cancer, which usually presents with intermittent, gross, painless hematuria that is present throughout micturition. This patient with terminal hematuria, peripheral eosinophilia, and dysuria first requires an evaluation for schistosomiasis using urine sediment microscopy. If this test is negative or his symptoms continue after treatment, an evaluation for bladder cancer using cystoscopy with biopsy (the gold standard) would be prudent. CT cystography is unlikely to be used. (Choice C) Expressed prostatic secretion culture is used to diagnose chronic bacterial prostatitis, which may present with dysuria and urinary frequency. However, this patient from Ghana with peripheral eosinophilia is more likely to have schistosomiasis. (Choice D) Abdominal radiography may diagnose urinary bladder calculi, a potential cause of dysuria and hematuria. However, peripheral eosinophilia is not typically associated with bladder calculi. Educational objective: Schistosomiasis is a parasitic fluke infection most commonly seen in sub-Saharan Africa. Chronic urinary schistosomiasis can cause dysuria, urinary frequency, terminal hematuria, and peripheral eosinophilia. Diagnosis is typically made by identifying parasite eggs by urine sediment microscopy.

Question 2

A 14-year-old boy is brought to the emergency department by his parents due to cough and difficulty breathing.  The patient has had a nonproductive cough for a week that worsens at night and prevents him from sleeping well.  This morning he has been short of breath while walking and speaking.  The boy has also had fever for the past 2 days.  Medical history is notable for end-stage renal disease due to obstructive uropathy from a congenital posterior urethral valve.  He received a living related donor kidney transplant 3 months ago.  Temperature is 38.2 C (100.8 F), blood pressure is 120/80 mm Hg, pulse is 98/min, and respirations are 31/min; pulse oximetry is 82% on room air.  Physical examination shows a tired-appearing boy in mild respiratory distress seated on a chair.  He is tachypneic with diffuse rales throughout the lungs.  His donor kidney is palpable in the lower abdomen and is nontender.  Laboratory studies show a creatinine of 0.6 mg/dL.  When questioned alone, the patient says that he has not been taking all his medications as prescribed.  Which of the following would most likely have prevented this patient's current illness?

Accepted Answer

Explanation: 11ec2b69_bfb9_384a_8f63_a31d739f0c50_MD0005_00 This patient has the classic history and physical examination findings of Pneumocystis jiroveci pneumonia (PCP). PCP is seen in patients with defects in cell-mediated immunity. It is most commonly seen in HIV-infected patients with CD4 cell counts <200 cells/mm³, but can also be seen in those receiving immune modulation following transplantation, as in this patient. PCP has an insidious onset and usually presents with low-grade fever, nonproductive cough, dyspnea, and tachypnea. Hypoxia is prominent and may be out of proportion to relatively mild findings on chest auscultation. Chest x-rays reveal diffuse, bilateral ground-glass opacities. Trimethoprim-sulfamethoxazole is the treatment of choice for suspected or proven PCP. Intravenous therapy should be used initially, with oral therapy initiated once the patient has signs of clinical recovery. Trimethoprim-sulfamethoxazole is highly effective when used prophylactically to prevent PCP in at-risk patients, and failure to adhere to trimethoprim-sulfamethoxazole prophylaxis is the most likely cause of this patient's disease. (Choice A) Fluconazole prophylaxis is commonly used for patients with cell-mediated immune defects to prevent esophageal or cutaneous candidiasis. Candida is an extremely rare cause of pneumonia. (Choice B) Influenza generally presents acutely with high fever, cough, myalgias, and pharyngitis in contrast to the more gradual onset of PCP. Although vaccination with inactivated intramuscular vaccine is recommended for all patients, it would not have prevented this patient's infection. (Choice C) Prednisone may be used for immunosuppression after transplantation, and it is sometimes used as adjunctive therapy for severe Pneumocystis pneumonia to improve air exchange. Despite its use for PCP treatment, prednisone has no role in PCP prevention. (Choice E) Antiretroviral therapy such as zidovudine plays an important role in preventing CD4 cell depletion and therefore risk of PCP in HIV-infected patients. However, zidovudine is not used for HIV-negative organ recipients. Educational objective: Pneumocystis jiroveci pneumonia (PCP) can cause life-threatening respiratory infection in immunocompromised patients, such as those with advanced HIV infection or who are on chronic immunosuppression. Prophylaxis, typically with trimethoprim-sulfamethoxazole, is indicated for at-risk patients. References: Prophylaxis for pneumocystis pneumonia (PCP) in non-HIV immunocompromised patients. (http://www.ncbi.nlm.nih.gov/pubmed/25269391)

Question 3

A 6-day-old boy is brought to the office for poor feeding.  He rejects the breast or bottle whenever his mother tries to feed him.  He sleeps all day and is very difficult to rouse.  Two days ago, the neonate was discharged from the nursery, where he received phototherapy for jaundice.  He was born at 39 weeks gestation by uncomplicated vaginal delivery.  The pregnancy was uncomplicated and prenatal laboratory studies were normal.  His family history is not significant.  The neonate currently takes no medications.  He is febrile and tachycardic.  Physical examination shows a lethargic infant with mild generalized jaundice.  Lungs are clear to auscultation.  Laboratory results are as follows:  Urinalysis shows positive leukocyte esterase and 15 white blood cells/hpf.  Blood, urine, and cerebrospinal fluid cultures are pending.  Which of the following treatment regimens is most appropriate for this patient?

Accepted Answer

Explanation: 11ec2b69_bfc0_1625_8f63_738cd33bf62f_MD0005_00 Newborns are prone to overwhelming bacterial infection due to their immature immune systems. Fever can be the first and only sign of a serious bacterial infection in neonates. Symptoms of urinary tract infection, bacteremia, and meningitis are nonspecific and can include the poor appetite and lassitude seen in this patient. Complete blood count may show leukocytosis. Indirect hyperbilirubinemia is usually physiologic in neonates, but sepsis-related hemolysis can cause persistent or worsening jaundice. All febrile neonates should undergo the following diagnostic tests: Complete blood count Blood culture Urinalysis Urine culture Cerebrospinal fluid cell count Cerebrospinal fluid culture The most common causes of serious bacterial infection in children are shown in the table. Escherichia coli urinary tract infection accounts for most bacterial infections in neonates. Listeria monocytogenes is currently rare but is still recognized due to potentially devastating complications. The recommended empiric regimen typically consists of ampicillin plus gentamicin or cefotaxime. Cefotaxime is preferred over gentamicin in areas with high rates of gentamicin resistance and suspected meningitis due to better cerebrospinal fluid penetration. (Choices A and D) Ceftriaxone can displace albumin-bound bilirubin in neonates, thereby increasing the amount of free bilirubin. The resultant hyperbilirubinemia can cross the blood-brain barrier and increase the risk of kernicterus. (Choice C) Broad-spectrum empiric antibiotics should be administered as soon as possible. Delaying therapy by even a few hours in an ill-appearing infant can result in permanent morbidity (eg, brain damage) or death. Antibiotics can eventually be narrowed based on culture growth and sensitivity. (Choice E) Sulfamethoxazole and other sulfonamides can worsen indirect hyperbilirubinemia by displacing bilirubin from albumin, thereby increasing the amount of free bilirubin. Trimethoprim-sulfamethoxazole is also avoided in patients age <6 weeks due to increased risk of methemoglobinemia. Educational objective: The most common causes of serious bacterial infection in neonates include Escherichia coli and Group B streptococcus. Broad-spectrum antibiotic therapy should be administered immediately to decrease potential morbidity and mortality. The preferred regimen for neonates consists of a combination of ampicillin and gentamicin or cefotaxime. Ceftriaxone and sulfonamides should be avoided due to risk of hyperbilirubinemia. References: Empirical treatment of neonatal sepsis: are the current guidelines adequate? (http://www.ncbi.nlm.nih.gov/pubmed/20584804) Fever without source in children 0 to 36 months of age. (http://www.ncbi.nlm.nih.gov/pubmed/16574521) Changing epidemiology of bacteremia in infants aged 1 week to 3 months. (http://www.ncbi.nlm.nih.gov/pubmed/22371459)

Question 4

A 26-year-old student comes to the emergency department 10 hours after his right arm was scratched by a bat.  He says, "I frequently explore caves, and bats do not always seem to like me."  He had a similar scratch 1 year ago and completed his anti-rabies vaccination series.  All his vaccinations are up-to-date.  His past medical history is otherwise insignificant.  He does not use tobacco, alcohol, or illicit drugs.  He is currently not taking any medications and has no known allergies.  What is the best management strategy for this patient?

Accepted Answer

Explanation: 11ec2b69_bfbc_1e7d_8f63_4b0cec19fdb8_MD0005_00 Rabies is an invariably fatal viral disease; it is primarily acquired from a bite or exposure to saliva of a rabid animal. Post-exposure prophylaxis can prevent the development of rabies infection. This patient's history of bat contact would place him at risk for rabies infection; post-exposure prophylaxis should be considered. There are 2 forms of prophylaxis available: passive immunization with rabies immune globulin and active immunization with rabies vaccination. Most patients are diagnosed following an exposure (post-exposure prophylaxis). However, persons whose work/travel involves likely exposure to rabies should receive a pre-exposure prophylaxis course. In the unvaccinated patient, post-exposure prophylaxis consists of active immunization with rabies vaccine and passive immunization with rabies immunoglobulin. This patient received a rabies vaccination 1 year prior to the recent bat exposure. For patients who have been previously vaccinated, 2 doses of active immunization with rabies vaccine are recommended. Passive immunization with rabies immunoglobulin in addition to active vaccination (Choice B) is not recommended in previously vaccinated individuals; this can lead to the impairment of the strength and rapidity of the immune response. (Choices A and E) Observation and reassurance (inpatient/outpatient) are inadequate as active immunization is warranted in this situation. (Choice C) There is evidence that passive immunization with rabies immune globulin blunts the immune response to the vaccine. Further immune globulin should be avoided in previously vaccinated individuals as some amount of antibody is still circulating. Educational objective: Previously vaccinated individuals who are potentially re-exposed to rabies should receive only a booster course of rabies vaccine (2 doses). Those without a history of immunization require both immune globulin and a full vaccination series (4 doses). References: Use of a reduced (4-dose) vaccine schedule for postexposure prophylaxis to prevent human rabies (http://www.ncbi.nlm.nih.gov/pubmed/20300058) Rabies vaccines (http://www.ncbi.nlm.nih.gov/pubmed/20831913) Inhibition of immune responses against rabies virus by monoclonal antibodies directed against rabies virus antigens (http://www.ncbi.nlm.nih.gov/pubmed/1441731)

Question 5

A 52-year-old woman is brought to the emergency department due to a day of fever, lethargy, and skin lesions. She is currently undergoing combination chemotherapy for diffuse large B-cell lymphoma, and her last treatment was 10 days ago. Yesterday, the patient developed a red rash on her right thigh. Within a few hours, a pustule formed in the center of the lesion, rapidly evolved into a dark bulla, and then ruptured and formed an ulcer. A second, similar skin lesion arose shortly thereafter. The patient has also had fever and chills and progressive weakness and lethargy. Temperature is 38.9 C (102 F), blood pressure is 110/60 mm Hg, and pulse is 106/min. She has an implanted central venous catheter with a subcutaneous port; the overlying skin is not erythematous or tender. Cardiopulmonary auscultation reveals clear lung fields and no cardiac murmurs. The abdomen is soft and nontender. Skin examination shows a nontender, necrotic ulcer with an erythematous rim and yellow-green, purulent exudate on the right thigh. There is another lesion with a hemorrhagic dark-bluish bulla and surrounding erythematous, indurated skin. Leukocyte count is 800/mm³ with 10% neutrophils. Which of the following is the most likely cause of this patient's skin lesions?

Accepted Answer

Explanation: This patient with a central venous catheter and chemotherapy-induced neutropenia developed rapidly progressive, ulcerative skin lesions, suggesting ecthyma gangrenosum. Ecthyma gangrenosum can be due to a number of different pathogens but is most commonly associated with Pseudomonas aeruginosa bacteremia in patients with immunocompromise (eg, neutropenia, immunosuppressant medications). Bacteria invade the perivascular structures (media, adventitia) of veins or arteries and induce secondary ischemic necrosis of the overlying tissue. This manifests with painless, red macules that rapidly progress to pustules/bullae and then quickly evolve into gangrenous ulcers with raised violaceous margins. The anogenital area, axilla, and extremities are most commonly affected, and single or multiple lesions may occur. Fever and signs of systemic illness are typically present. (Choice A) Clostridial myonecrosis, also called gas gangrene, is associated with fever, severe muscle pain, and purple-colored bullae. This patient does not have pain, making this condition unlikely. (Choice C) Patients with neutropenia and central venous access are at greater risk for invasive Candida infections. Skin lesions may occur but typically manifest as clusters of painless pustules on an erythematous base, sometimes with necrotic centers. This patient had a rapidly progressive bullous lesion that evolved into an ulcer, suggesting ecthyma gangrenosum. (Choice D) Mycosis fungoides is a cutaneous T-cell lymphoma that typically causes slowly (not rapidly) progressive skin lesions that appear as patches, plaques, tumors, or erythroderma. (Choice E) Pyoderma gangrenosum is a neutrophilic dermatosis that is usually associated with inflammatory bowel disease or an arthritides. Lesions typically begin as inflammatory nodules, pustules, or vesicles and quickly evolve to ulcers; however, they are usually quite painful. Educational objective: Ecthyma gangrenosum is most commonly seen in immunocompromised patients with Pseudomonas aeruginosa bacteremia. Manifestations typically include the rapid evolution of >1 skin lesion from an erythematous macule to a pustule or bullae and then into a nonpainful gangrenous ulcer. Fever and systemic signs of illness are common.

Question 6

A 3-year-old boy is brought to the clinic by his mother for evaluation of fever and rash.  He was bitten by an insect yesterday, resulting in an itchy red "bump" on his right thigh.  The lesion has rapidly enlarged and become tender to the touch.  The mother says, "My son awoke from his nap today with fever and chills, so I am worried that he has an infection.  I rubbed a steroid medication from the drugstore on his skin, but he says it is still painful."  The patient has no chronic medical conditions and takes no medications.  He has no known allergies.  Temperature is 39.5 C (103.1 F).  Examination reveals an uncomfortable-appearing boy sitting in his mother's lap.  Cardiopulmonary examination is normal.  Skin examination reveals an 8-cm area of bright-red, tense, and warm skin on the right upper thigh that is well demarcated and raised relative to the surrounding, unaffected skin.  No fluctuance or discharge is noted.  Three tender 1.5-cm right inguinal lymph nodes are present.  The remainder of the examination is unremarkable.  Which of the following is the most likely diagnosis?

Accepted Answer

Explanation: 11ec2b69_bfc1_75b7_8f63_e50db153a5a9_MD0005_00 Erysipelas is a common, rapidly spreading, superficial bacterial infection in young children and older adults. Infection develops in a break in the skin, such as an abrasion or excoriated insect bite, and is most commonly caused by Streptococcus pyogenes, or group A Streptococcus. Physical examination shows a bright-red, well-demarcated, and raised area that is tender and tense. Typical affected areas include the ear, malar area of the face, and lower extremities. Localized lymphadenopathy and systemic symptoms (eg, fever, chills), as seen in this patient, are common. Erysipelas differs from cellulitis in its rapid onset and well-demarcated and raised appearance. Treatment is a penicillin (eg, ampicillin, amoxicillin). Erysipelas (Choice A) Abscess presents with a tender, fluctuant nodule due to a collection of pus beneath or within the dermis. Purulent drainage and fever may be present. This patient's rash is not fluctuant, and no purulent drainage is present. Abscess (Choice C) Erythema migrans is a manifestation of Lyme disease and may present as a rash with fever and localized lymphadenopathy. However, the rash is typically not tender and presents as a bull's eye lesion with central clearing. (Choice D) Impetigo is also a superficial bacterial infection but typically presents with pustules and honey-colored crusting. Systemic symptoms, such as fever and chills in this patient, are uncommon. (Choice E) Necrotizing fasciitis is also a rapidly spreading infection but classically presents with pain out of proportion to examination findings, which is not present in this patient. In addition, findings in necrotizing fasciitis can include crepitus, bullae, and ecchymoses. Educational objective: Erysipelas, most commonly caused by Streptococcus pyogenes, presents with fever and acute, rapidly spreading erythema with well-demarcated, raised borders. First-line treatment is a penicillin (eg, ampicillin, amoxicillin). References: Impetigo, erysipelas and cellulitis. (http://www.ncbi.nlm.nih.gov/pubmed/26866211)

Question 7

A previously healthy 20-year-old man is brought to the emergency department for fever, dysphagia, drooling, and poor coordination.  The symptoms started last week with mild fever, throat pain, and malaise.  He was able to eat some food but is afraid to drink any fluids as he feels his "throat closing up."  The patient, an anthropology student, went on a school trip 2 months ago during which he explored several caves.  He took several over-the-counter analgesic medications without relief.  He does not recall any bites, scratches, or animal exposures.  The patient has received all standard immunizations and takes no medications.  He is febrile and tachycardic.  Examination shows dehydration, lethargy, and ataxia.  Drool is pooling in his mouth.  No pharyngeal erythema or exudates are seen.
Which of the following is the most likely diagnosis in this patient?

Accepted Answer

Explanation: 11ec2b69_bfbb_823b_8f63_b17471166f7d_MD0005_00 This patient's dysphagia, drool, and history of cave exposure are concerning for rabies transmitted by bats. Hydrophobia is pathognomonic for rabies; water triggers pharyngeal spasms that cause the patient to be frightened of drinking. The illness usually starts with a few days of nonspecific prodromal symptoms, including fever and malaise. Neurologic symptoms (eg, confusion, lethargy, paralysis, aphasia) develop later in the course of the disease. In developing countries, domestic animals (eg, dogs) are common sources of infection. In the United States, bats and wild animals (eg, raccoons) are the most common reservoirs of infection. The acquisition of rabies from bats can occur from an unrecognized bite or a scratch, and possibly by inhalation of aerosolized viral particles. Bats are found in all states, and spelunking (cave exploration) is a risk factor for rabies acquisition from bats. (Choice A) Epiglottitis can cause dysphagia, odynophagia, and drooling, but affected patients typically have stridor and rapid upper airway obstruction with illness onset. (Choice B) Histoplasmosis can occur after spelunking from exposure to bird or bat droppings. However, respiratory symptoms (eg, cough, chest pain, hemoptysis) are usually prominent, and hydrophobia is not seen in histoplasmosis. (Choice C) Pertussis typically manifests as paroxysmal episodes of cough. This patient has no cough or rhinorrhea, as is typically seen in pertussis. (Choice E) Tetanus is characterized by involuntary muscle contractions but is unlikely to occur in a fully vaccinated patient. Educational objective: Acquisition of rabies from bats can occur from an unrecognized bite or scratch. Hydrophobia is the hallmark sign of rabies. References: Rabies surveillance in the United States during 2012. (http://www.ncbi.nlm.nih.gov/pubmed/24004227) Diagnosis, management and post-mortem findings of a human case of rabies imported into the United Kingdom from India: a case report. (http://www.ncbi.nlm.nih.gov/pubmed/24708671)

Question 8

A 32-year-old woman comes to the emergency department due to 7 days of fever and dry cough. She has also had progressive shortness of breath with minimal walking and climbing stairs. The patient was diagnosed with HIV infection a year ago and is not currently on antiretroviral treatment. She does not use tobacco, alcohol, or illicit drugs. Temperature is 38.4 C (101.1 F), blood pressure is 110/64 mm Hg, pulse is 106/min, and respiratory rate is 26/min. Pulse oxymetry is 87% on room air and decreases to 82% with minimal walking. Oropharyngeal thrush is present. Lung auscultation reveals scattered bilateral crackles and rhonchi. The abdomen is soft and nontender without organomegaly. No cyanosis, clubbing, or edema is present. Chest x-ray reveals diffuse interstitial opacities bilaterally. CD4 count is 85/mm³. The patient is admitted and started on empiric therapy. Twenty-four hours after admission, the induced sputum analysis is negative for Pneumocystis. Which of the following is the most appropriate indication for the use of corticosteroids in this patient?

Accepted Answer

Explanation: Patients with HIV who have moderate or severe Pneumocystis pneumonia (PCP) often have respiratory decompensation during the first 2-3 days of treatment due to organism lysis, which stimulates an inflammatory response. To reduce the risk of intubation and death, corticosteroids are used in those with arterial blood gas (ABG) evidence of alveolar-arterial oxygen gradient >35 mm Hg and/or arterial oxygen tension (PaO₂) <70 mm Hg (on room air). Some research suggests that pulse oxymetry readings <92% indicate a need for corticosteroids (without ABG). However, ABG remains the standard of care and helps determine whether intravenous antibiotics and hospitalization in the intensive care unit are needed. (Choice B) Arterial oxygen tension <70 mm Hg (not <85 mm Hg) on room air indicates a need for corticosteroids. (Choice C) Patients with CD4 counts <200/mm³ are at high risk for PCP and are usually put on prophylaxis. However, CD4 count does not determine the need for concomitant corticosteroids during antimicrobial treatment. (Choice D) Oropharyngeal thrush is commonly seen in those with PCP, an indication of significantly weakened immunity. This patient's thrush should be treated (eg, fluconazole), but the presence of thrush does not modulate the need for concomitant corticosteroids. (Choice E) Although drug reactions are common with trimethoprim-sulfamethoxazole (the first-line treatment for PCP), corticosteroids are used to prevent inflammation from organism lysis (not drug reaction). Educational objective: Patients with HIV with Pneumocystis pneumonia should receive corticosteroids in addition to antimicrobials if arterial blood gas analysis shows alveolar-arterial oxygen gradient >35 mm Hg and/or arterial oxygen tension <70 mm on room air.

Question 9

A 10-year-old boy is brought to the emergency department due to low-grade fever over the last 3 days that has not resolved with acetaminophen.  For the last 2 days, the patient has also had a diffuse headache that is now severe and associated with nausea.  Today he is weak and has diffuse myalgias and arthralgias but is able to bear weight and walk with some assistance.  However, he has no photophobia, vomiting, or diarrhea.  The patient returned from a family camping trip in North Carolina a week ago, and no other family members have symptoms.  He has no chronic medical conditions, and his immunizations are up to date.  Temperature is 38.8 C (101.8 F) and pulse is 100/min.  The patient appears lethargic.  Oropharyngeal mucosa and tympanic membranes are normal.  The neck is supple.  The lungs are clear to auscultation.  Cardiac examination reveals no rubs or murmurs.  The abdomen is soft and nontender.  Skin examination shows a macular, erythematous rash and few petechiae on bilateral wrists and ankles.  There are no other skin lesions.  Joints have a full range of motion and no overlying erythema.  Kernig and Brudzinski signs are both negative.  Laboratory results are as follows:  Which of the following is the best therapy option for this patient?

Accepted Answer

Explanation: 11ec2b69_bfbe_dda2_8f63_9f80c58e34a6_MD0005_00 Rocky Mountain spotted fever (RMSF) is a tick-borne illness caused by Rickettsia rickettsii. The classic triad of symptoms includes fever, headache, and rash. Early nonspecific manifestations (eg, fever, nausea, myalgias, arthralgias) are followed by the development of erythematous macules on the wrists and ankles around days 3-5 of illness. Rash may spread to the trunk, palms, and soles, and macules often evolve into petechiae. Although initial leukocyte count is typically normal, thrombocytopenia, hyponatremia, and transaminitis are characteristic. RMSF is diagnosed presumptively based on clinical findings as serologic testing is generally negative in early disease. Empiric antibiotics are initiated as soon as possible without waiting for confirmatory test results, as a delay in treatment can lead to serious complications (eg, encephalitis, pulmonary edema, arrhythmia) and increased mortality. Doxycycline is the recommended antibiotic for all patients, including children and pregnant women. The risk of teeth discoloration is minimal with a short treatment course; no other medications are as safe and effective. (Choice A) Amoxicillin is preferred over doxycycline for patients age <8 with Lyme disease. Lyme is also transmitted by ticks but leads to erythema migrans (rash with central clearing) rather than petechiae. (Choice B) Ceftriaxone treats meningococcal meningitis, which presents with fever, headache, and a petechial/purpuric rash. However, symptoms typically manifest rapidly (within hours) and often include intense myalgias and meningismus (eg, nuchal rigidity, Kernig, Brudzinski). This patient's relatively gradual onset of symptoms and lack of neck stiffness make meningitis less likely. (Choice D) Intravenous immunoglobulin is the treatment for Kawasaki disease (KD), which is characterized by fever, rash, conjunctivitis, lymphadenopathy, strawberry tongue, and swelling of the hands and feet. Rash associated with KD is diffuse and polymorphous, not confined to the wrists and ankles. (Choice E) No therapy is generally required for viral infections such as infectious mononucleosis, which can lead to fever and fatigue but classically causes pharyngitis and lymphadenopathy. In addition, although maculopapular or petechial rash can accompany the illness at times, leukocytosis (eg, 12,000-18,000 leukocytes/mm³) with lymphocytosis is typical. Educational objective: Rocky Mountain spotted fever is a tick-borne illness characterized by fever, headache, and an erythematous macular and/or petechial rash on the wrists and ankles. Prompt, empiric administration of doxycycline is the treatment of choice. References: Rocky Mountain spotted fever in children. (http://www.ncbi.nlm.nih.gov/pubmed/23481111)

Question 10

An 8-year-old girl is brought to the physician for abnormal behavior.  She has been acting inappropriately, crying, and laughing without apparent reason for the past 2 weeks.  At school, she was restless and easily distracted.  Last week, her parents noted strange movements of the girl's hands that improved when she slept.  On the day before presentation, her parents noticed rapid jerking movements of her face and feet.  The girl has had minor, self-resolving upper respiratory infections but has otherwise been healthy.  She takes no medications and her vaccinations are up-to-date.  Examination shows an alert and cooperative girl with normal vital signs.  Facial grimacing and tongue fasciculations are seen.  The lungs are clear to auscultation and a II/VI holosystolic murmur is heard at the apex.  When the girl speaks, distinct changes in the volume and pitch of her voice are noted.  Muscular tone is mildly decreased globally.  Pronator sign is positive, and the relaxation phase of the patellar reflex is delayed. 
Which of the following is the most likely diagnosis?

Accepted Answer

Explanation: 11ec2b69_bfbc_babe_8f63_25b242917880_MD0005_00 Acute rheumatic fever (ARF) is a complication of untreated streptococcal pharyngitis. Patients and families may not remember the initial self-resolving infection. The diagnosis is based on the J♥NEScriteria (Table). Two major or 1 major and 2 minor criteria are required, although the diagnosis can be made on the presence of Sydenham chorea (SC) or carditis alone. This patient's examination findings are classic for SC (also known as Saint Vitus dance), the most common acquired chorea in children. Emotional lability and decline in school performance are typically the earliest neurologic manifestations, followed by distal hand movements that progress to facial grimacing and feet jerking. Movements are typically irregular and rapid. Patients also have decreased strength throughout, and the relaxation phase of the patellar reflex is usually delayed. In addition, pronator drift (involuntary hyperpronation of extended arms) is present. The diagnosis is based on clinical presentation. SC usually develops 1-8 months after the initialstreptococcal infection; carditis and arthritis develop within 3 weeks. This patient's murmur is concerning for carditis and should be evaluated by echocardiography. (Choice A) Attention deficit hyperactivity disorder is characterized by inattention, impulsivity, and hyperactivity that persist for >6 months. The physical examination is otherwise normal. (Choice B) Huntington disease is an autosomal dominant disorder caused by a trinucleotide repeat expansion. The psychiatric symptoms, chorea, and dementia typically manifest at age 30-50; onset is uncommon during childhood. (Choice D) Tardive dyskinesia is a movement disorder that occurs in patients on dopamine receptor-blocking agents (eg, antipsychotic agents, metoclopramide). Chorea is a side effect of these medications; this child takes no medications. (Choice E) Tourette syndrome is characterized by involuntary motor and vocal tics that begin at age 2-15. The physical examination is otherwise normal and chorea is not seen. Educational objective: Sydenham chorea is one of the major manifestations of acute rheumatic fever and is the most commonly acquired chorea in children. It is characterized by emotional lability and irregular, rapid jerking movements of the face, hands, and feet. References: Sydenham's chorea in western Pennsylvania. (http://www.ncbi.nlm.nih.gov/pubmed/16533893) Prevention of rheumatic fever and diagnosis and treatment of acute Streptococcal pharyngitis: a scientific statement from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee of the Council on Cardiovascular Disease in the Young, the Interdisciplinary Council on Functional Genomics and Translational Biology, and the Interdisciplinary Council on Quality of Care and Outcomes Research: endorsed by the American Academy of Pediatrics. (http://www.ncbi.nlm.nih.gov/pubmed/19246689) Seminar on choreas. (http://www.ncbi.nlm.nih.gov/pubmed/16781989)

Question 11

A 16-year-old boy is brought to an urgent care center by his father due to a rash.  The rash started as a small, red area on his thigh about 5 days ago.  The patient says, "I first noticed the rash the day after I went hiking.  I got a lot of bug bites so I didn't think much of it at first."  The area has since increased in size and is tender to the touch.  The patient has had no fever or other rashes.  He has no medical issues and is up to date on immunizations.  He is on the school wrestling team and lives with his parents, grandparents, and 2 younger siblings.  His grandfather was recently diagnosed with shingles; all other family members are healthy.  Vital signs are normal.  Physical examination reveals a well-appearing boy in no distress.  Skin examination reveals a poorly demarcated, flat 8 cm x 8 cm area of tender, warm, confluent erythema on the anterior left thigh.  There is no fluctuance or drainage.  The remainder of the examination is unremarkable.  Which of the following pathogens is the most likely cause of this patient's rash?

Accepted Answer

Explanation: 11ec2b69_bfc1_eae8_8f63_cbb856ae463f_MD0005_00 This patient has a nonpurulent cellulitis, a bacterial infection that involves the deep dermis or subcutaneous fat. Presentation includes tender and warm erythema with ill-defined, flat borders. Infection typically develops after a break in the skin, as in this patient with an insect bite. The course is often indolent, with increasing size and development of systemic symptoms (eg, fever) after several days. Fluctuance and purulent drainage are not present. cellulitis The most common cause of cellulitis is Streptococcus pyogenes, also known as group A Streptococcus. Treatment is systemic antibiotic therapy (eg, cephalexin) for ≥5 days. Well-appearing, afebrile patients can be treated as outpatients. (Choice A) Borrelia burgdorferi causes Lyme disease, which can present with erythema migrans. This classic bullseye rash is not painful and is usually accompanied by nonspecific symptoms, such as fever, malaise, and headache, none of which are present in this patient. In addition, he developed a rash the day after a bug bite, whereas erythema migrans typically develops 1-2 weeks later. (Choice B) Staphylococcus aureus is the most commonly isolated pathogen in abscesses and is less commonly implicated in nonpurulent cellulitis. Although this patient is at risk for methicillin-resistant S aureus due to contact sports, S pyogenes is still the most common cause of isolated cellulitis, and there is no fluctuance or purulent drainage suggestive of an abscess. (Choice D) Trichophyton species can cause tinea corporis, a dermatophyte infection common in athletes who participate in contact sports. The rash is pruritic with central clearing and raised borders, and is not tender or warm. (Choice E) Varicella zoster virus can cause herpes zoster, or shingles, in patients who have had chickenpox. Shingles is rare in children and young adults, especially those vaccinated against varicella. In addition, the rash is vesicular, which is not the case in this patient. Educational objective: Cellulitis is an infection of the deep dermis or subcutaneous fat that presents with poorly defined, flat, and tender erythema. The most common cause of nonpurulent cellulitis is Streptococcus pyogenes. References: Impetigo, erysipelas and cellulitis. (http://www.ncbi.nlm.nih.gov/pubmed/26866211)

Question 12

A previously healthy 5-year-old boy is brought to the physician with 2 days of sore throat.  He has some pain with swallowing but is drinking fluids normally.  He also has fever but no rhinorrhea, cough, or congestion.  The boy has no known allergies and his immunizations are up-to-date.  He recently started kindergarten, and other children at the school have been ill.  His temperature is 38.9 C (102 F), blood pressure is 110/60 mm Hg, pulse is 98/min, and respirations are 20/min.  Physical examination shows purulent exudates on the tonsils and posterior pharynx.  Anterior cervical nodes are enlarged and tender.  Lungs are clear to auscultation.  A rapid streptococcal antigen test result is positive.  What is the best next step in management of this patient?

Accepted Answer

Explanation: 11ec2b69_bfb7_1568_8f63_4b3bd2afc5f5_MD0005_00 This patient's presentation of fever and sore throat without upper respiratory symptoms and his physical examination findings of tonsillar exudates and cervical lymphadenopathy are classic for streptococcal pharyngitis. Group A streptococcal (GAS) pharyngitis is most common in children age 5-15 and occurs in the late fall, winter, and early spring. Tonsillar exudates and tender anterior cervical lymph nodes are often seen on examination. Diagnosis should be confirmed with throat culture or rapid antigen testing prior to initiation of antibiotics. The rapid streptococcal antigen test (RSAT) is highly specific, and antibiotic treatment can be initiated after a positive test. However, due to the test's poor sensitivity, throat cultures must be obtained after all negative RSATs in children (Choice B). Throat cultures are not necessary if the RSAT is positive. Penicillin and amoxicillin are the first-line treatment options for patients with streptococcal pharyngitis, as these medications are safe, narrow spectrum, and cost-effective. The goals of treatment are to reduce symptom severity and duration, decrease spread to close contacts, and prevent acute rheumatic fever. (Choice A) Heterophile antibody testing (eg, Monospot) is used to identify infectious mononucleosis (IM) caused by the Epstein-Barr virus. IM is most common in adolescents and presents with fever; fatigue; exudative pharyngitis; and diffuse, posterior cervical lymphadenopathy. This patient's age, anterior cervical lymphadenopathy, and positive RSAT make IM unlikely. (Choice D) Broad spectrum antibiotics, such as amoxicillin-clavulanic acid, are not indicated as GAS is highly sensitive to penicillin and amoxicillin. Cephalosporins can be used to treat streptococcal pharyngitis in penicillin-allergic patients. Inappropriate prescription of these other antibiotics lead to emerging resistance of bacterial strains in general. (Choice E) Nonsteroidal anti-inflammatory medications and hydration are adequate for treatment of viral pharyngitis, which typically presents with upper respiratory symptoms (eg, rhinorrhea, cough). Symptomatic treatment serves as an adjunct to antibiotics in streptococcal pharyngitis. Educational objective: Streptococcal pharyngitis presents with fever, sore throat, tonsillar exudates, and tender anterior cervical lymphadenopathy. Because the rapid streptococcal antigen test is highly specific, treatment with penicillin or amoxicillin can be initiated after a positive test without a confirmatory throat culture. References: Rapid antigen detection testing in diagnosing group A beta-hemolytic streptococcal pharyngitis. (http://www.ncbi.nlm.nih.gov/pubmed/17009909) Accuracy and precision of the signs and symptoms of streptococcal pharyngitis in children: a systematic review. (http://www.ncbi.nlm.nih.gov/pubmed/22048053)

Question 13

A 52-year-old woman is brought to the emergency department due to a day of fever, lethargy, and skin lesions. She is currently undergoing combination chemotherapy for diffuse large B-cell lymphoma, and her last treatment was 10 days ago. Yesterday, the patient developed a red rash on her right thigh. Within a few hours, a pustule formed in the center of the lesion, rapidly evolved into a dark bulla, and then ruptured and formed an ulcer. A second, similar skin lesion arose shortly thereafter. The patient has also had fever and chills and progressive weakness and lethargy. Temperature is 38.9 C (102 F), blood pressure is 110/60 mm Hg, and pulse is 106/min. She has an implanted central venous catheter with a subcutaneous port; the overlying skin is not erythematous or tender. Cardiopulmonary auscultation reveals clear lung fields and no cardiac murmurs. The abdomen is soft and nontender. Skin examination shows a nontender, necrotic ulcer with an erythematous rim and yellow-green, purulent exudate on the right thigh. There is another lesion with a hemorrhagic dark-bluish bulla and surrounding erythematous, indurated skin. Leukocyte count is 800/mm³ with 10% neutrophils. Which of the following statements regarding this patient's current condition is most accurate?

Accepted Answer

Explanation: This patient with neutropenia and an indwelling central catheter has ecthyma gangrenosum, raising strong suspicion for Pseudomonas aeruginosa bacteremia. This is a life-threatening infection; the patient should receive blood and wound cultures and then be initiated on empiric intravenous antibiotics. Because Pseudomonas aeruginosa is often multi-drug resistant, patients with suspected bacteremia usually require combination empiric therapy to improve the likelihood of adequate coverage. Common regimens include an antipseudomonal beta-lactam (eg, piperacillin-tazobactam) and aminoglycoside (eg, gentamicin). Selected cephalosporins, monobactams, fluoroquinolones, and carbapenems may also be used. Patients are typically transitioned to monotherapy once culture results and antibiotic sensitivities are available. (Choice A) Pyoderma gangrenosum is typically associated with auto-inflammatory disorders but usually causes painful (not painless) lesions. (Choice B) Invasive Candida infections frequently cause endophthalmitis and necessitate ophthalmologic evaluation. However, skin lesions due to hematogenous dissemination of Candida usually manifest as grouped pustules on an erythematous base with or without necrotic centers (not bullous, ulcerative lesions). (Choice C) Patients with clostridial myonecrosis usually require extensive surgical debridement, but this condition is associated with significant pain. Surgical debridement is not typically required for ecthyma gangrenosum. (Choice E) Mycosis fungoides is often treated with skin-directed corticosteroids, chemotherapy, phototherapy, and/or radiation. Educational objective: Patients with immunocompromise who develop ecthyma gangrenosum likely have Pseudomonas aeruginosa bacteremia. Urgent blood and wound cultures are required; patients should then receive empiric intravenous antibiotics with 2 medications active against Pseudomonas. Commonly, patients receive a beta-lactam (eg, piperacillin-tazobactam) and an aminoglycoside (eg, gentamicin).

Question 14

An 8-year-old girl is brought to the physician for abnormal behavior.  She has been acting inappropriately, crying, and laughing without apparent reason for the past 2 weeks.  At school, she was restless and easily distracted.  Last week, her parents noted strange movements of the girl's hands that improved when she slept.  On the day before presentation, her parents noticed rapid jerking movements of her face and feet.  The girl has had minor, self-resolving upper respiratory infections but has otherwise been healthy.  She takes no medications and her vaccinations are up-to-date.  Examination shows an alert and cooperative girl with normal vital signs.  Facial grimacing and tongue fasciculations are seen.  The lungs are clear to auscultation and a II/VI holosystolic murmur is heard at the apex.  When the girl speaks, distinct changes in the volume and pitch of her voice are noted.  Muscular tone is mildly decreased globally.  Pronator sign is positive, and the relaxation phase of the patellar reflex is delayed. The child's diagnosis is discussed with her parents, who would like to know more about treatment of the condition.  Which of the following is the most appropriate medication for this patient?

Accepted Answer

Explanation: 11ec2b69_bfbd_56ff_8f63_1960700268de_MD0005_00 Streptococcal pharyngitis is the primary risk factor for acute rheumatic fever (ARF), and treatment with oral penicillin is the best method of primary prevention. Sydenham chorea (SC) is a cardinal feature of rheumatic fever, and affected patients should receive long-acting intramuscular penicillin until adulthood for secondary prevention, even if there is no active pharyngitis. The goal of antibiotic therapy is to eradicate group A streptococcus to prevent recurrent ARF and worsening rheumatic heart disease. Treatment of SC itself is primarily supportive with complete resolution occurring within months in most patients. Corticosteroids can reduce the duration of symptoms but are typically reserved for severe cases. (Choice A) Nonsteroidal anti-inflammatory agents such as ibuprofen or aspirin can be used for symptomatic relief of arthritis in patients with ARF. This patient has no symptoms of arthritis. In addition, aspirin is generally avoided in children due to the risk of Reye syndrome. (Choice B) Haloperidol is a powerful dopamine antagonist that can be used to control chorea in patients with severe symptoms that may result in self-injury. Haloperidol is not used in patients with mild-to-moderate symptoms due to the risk of extrapyramidal reactions. (Choice C) Methylphenidate is a stimulant medication for attention deficit hyperactivity disorder. It is inappropriate for SC as the neuropsychiatric symptoms should resolve spontaneously. (Choice E) Tetrabenazine is a dopamine antagonist used for Huntington disease but not SC. Educational objective: Patients with Sydenham chorea should be started on penicillin as soon as possible to eliminate carriage of group A streptococcus. Penicillin should be continued until adulthood with the goal of preventing recurrent rheumatic fever. References: Prevention of rheumatic fever and diagnosis and treatment of acute Streptococcal pharyngitis: a scientific statement from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee of the Council on Cardiovascular Disease in the Young, the Interdisciplinary Council on Functional Genomics and Translational Biology, and the Interdisciplinary Council on Quality of Care and Outcomes Research: endorsed by the American Academy of Pediatrics. (http://www.ncbi.nlm.nih.gov/pubmed/19246689) Discontinuing rheumatic fever prophylaxis in selected adolescents and young adults. a prospective study. (http://www.ncbi.nlm.nih.gov/pubmed/8439112) Comprehensive treatment of Huntington disease and other choreic disorders. (http://www.ncbi.nlm.nih.gov/pubmed/22761268)

Question 15

A 22-year-old woman comes to the office in April due to sinus congestion.  Three weeks ago, she had subjective fever, myalgia, nasal congestion, sore throat, and dry cough a few days after visiting her sick nephew.  Her symptoms initially improved with over-the-counter analgesics and decongestants, but she now has had 2 weeks of purulent nasal discharge, throbbing headache, and facial pain.  The patient has a history of type 1 diabetes mellitus managed with premeal insulin boluses and an insulin pump for continuous subcutaneous insulin infusion.  She also has a history of childhood eczema.  She does not use tobacco, alcohol, or illicit drugs.  The patient has no known drug allergies.  Temperature is 38 C (100.4 F), blood pressure is 118/74 mm Hg, and pulse is 90/min.  Physical examination shows swollen and erythematous nasal turbinates with yellowish-green nasal secretions.  The left maxillary sinus is tender to palpation, with no sinus transillumination.  The tympanic membranes and oropharyngeal mucosa are normal.  Cervical lymph nodes are not enlarged or tender and lungs are clear to auscultation.  Fingerstick blood glucose is 120 mg/dL.  Which of the following is the best next step in management of this patient?

Accepted Answer

Explanation: 11ec2b69_bfc0_b266_8f63_27a0b4543304_MD0005_00 This patient had symptoms of a viral upper respiratory infection and then developed 2 weeks of purulent nasal discharge, headache, and facial pain, suggesting acute bacterial rhinosinusitis (ABRS). Acute rhinosinusitis is the symptomatic inflammation of the nasal and sinus mucosa for <4 weeks. The majority of cases are due to viral upper respiratory pathogens (eg, influenza virus, rhinovirus, adenovirus) and resolve within 10 days. However, 2%-10% of patients develop a secondary bacterial infection, most commonly with Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis. Diagnosis of ABRS is typically made when >1 of the following is present: Persistent symptoms/signs of rhinosinusitis for >10 days Severe symptoms, high fever (>39 C [102.2 F]), purulent nasal discharge, and/or facial pain for >3 consecutive days "Double sickening" - initial improvement of viral upper respiratory symptoms for 5-6 days, followed by clinical deterioration (eg, worsened fever, headache, nasal discharge) Patients with ABRS are usually treated with 5-7 days of oral amoxicillin-clavulanate to reduce symptom duration. Intranasal saline irrigation and analgesics are also often recommended (Choice A) Patients with poorly controlled diabetes mellitus (particularly with ketoacidosis) are at risk for rhino-orbital mucormycosis, which is treated with intravenous fungal medications. Manifestations typically progress rapidly and include fever, nasal necrosis, facial swelling, sinusitis, and headache. This patient on an insulin pump likely has well-controlled diabetes mellitus; she would be at low risk for mucormycosis. (Choice B) Allergic rhinitis can be treated with pollen avoidance and intranasal glucocorticoids. Manifestations typically include paroxysms of sneezing, rhinorrhea, and nasal itching. Fever and purulent nasal secretions would be atypical. (Choice C) Patients with evidence of bacterial infection that has spread beyond the sinuses and into the central nervous system, orbit, or surrounding tissue are considered to have complicated sinusitis and require laboratory testing and imaging. This patient's symptoms are localized to the sinuses and nasal cavity; empiric antibiotics are sufficient. (Choice E) Patients with viral rhinosinusitis can be reassured and advised to undergo symptomatic treatment (eg, analgesics). This patient has several features of ABRS, including persistent symptoms and "double sickening"; she requires antibiotics. Educational objective: Acute rhinosinusitis is most commonly due to viral pathogens and usually resolves within 10 days. Patients with persistent symptoms >10 days, severe symptoms, or deterioration after several days of improvement often have acute bacterial rhinosinusitis, which is usually treated empirically with 5-7 days of oral amoxicillin-clavulanate. References: Clinical practice guideline: adult sinusitis. (http://www.ncbi.nlm.nih.gov/pubmed/17761281) IDSA clinical practice guideline for acute bacterial rhinosinusitis in children and adults. (http://www.ncbi.nlm.nih.gov/pubmed/22438350)

Question 16

A previously healthy 20-year-old man is brought to the emergency department for fever, dysphagia, drooling, and poor coordination.  The symptoms started last week with mild fever, throat pain, and malaise.  He was able to eat some food but is afraid to drink any fluids as he feels his "throat closing up."  The patient, an anthropology student, went on a school trip 2 months ago during which he explored several caves.  He took several over-the-counter analgesic medications without relief.  He does not recall any bites, scratches, or animal exposures.  The patient has received all standard immunizations and takes no medications.  He is febrile and tachycardic.  Examination shows dehydration, lethargy, and ataxia.  Drool is pooling in his mouth.  No pharyngeal erythema or exudates are seen. The patient's family is concerned about his prognosis.  Which of the following is the most accurate response?

Accepted Answer

Explanation: 11ec2b69_bfbb_d05c_8f63_015200a1f0ba_MD0005_00 Human rabies is a life-threatening infection characterized by hydrophobia and neurologic decline. Post-exposure prophylaxis is effective only in preventing disease prior to manifestation of symptoms. After disease onset, treatment is primarily palliative, and most patients suffer from coma and death within weeks of illness onset. Family members should be advised to expect long-term neurologic deficits in the rare chance that the patient does survive (Choice A). (Choice B) Rabies is a viral infection; antibiotics have no role in its treatment. (Choice C) Post-exposure prophylaxis with rabies immune globulin and rabies vaccine can help prevent onset of the disease; it is not helpful after the onset of clinical manifestations. (Choice D) The Milwaukee protocol is an experimental approach to rabies treatment that consists of therapeutic coma induction and antiviral therapy. Although a few patients with suspected rabies have survived with this protocol, several have died despite this investigative therapy. Routine implementation of the protocol is currently not recommended. Educational objective: Rabies is an almost universally fatal disease once patients are symptomatic. Treatment is primarily palliative. References: Diagnosis, management and post-mortem findings of a human case of rabies imported into the United Kingdom from India: a case report. (http://www.ncbi.nlm.nih.gov/pubmed/24708671) Rabies surveillance in the United States during 2012. (http://www.ncbi.nlm.nih.gov/pubmed/24004227)

Question 17

A 54-year-old man comes to the office due to 3 months of urinary frequency and urgency.  He has also had discomfort in the pelvic region and pain during ejaculation.  The patient's symptoms temporarily improved during a week-long course of trimethoprim-sulfamethoxazole for urinary tract infection but recurred shortly after treatment concluded.  He has a history of hypertension well controlled with lisinopril.  He also had a single episode of gonorrhea 20 years ago that was treated with penicillin.  The patient has a 20-pack-year smoking history but quit 4 years ago.  He drinks alcohol on social occasions and does not use illicit drugs.  He is monogamous with his wife.  Temperature is 37 C (98.6 F), blood pressure is 120/70 mm Hg, and pulse is 80/min.  The abdomen is soft and nontender with no organomegaly.  Genital examination shows a circumcised penis with no urethral discharge.  Testicular examination shows no abnormalities.  The prostate is slightly enlarged with minimal tenderness and no nodules.  Urinalysis shows 20-30 leukocytes/HPF and moderate bacteruria but no erythrocytes.  Prostate-specific antigen level is within normal limits.  Which of the following is the most appropriate management of this patient?

Accepted Answer

Explanation: This patient has a 3-month history of urinary symptoms and pelvic pain with evidence of urine leukocytes and bacteruria, suggesting chronic bacterial prostatitis. Chronic bacterial prostatitis is a common condition of young and middle-aged men due primarily to intraprostatic reflux of urine with microbial seeding of the prostate. Pathogens are similar to those that cause cystitis and include Escherichia coli (75%-80%), Enterococcus, Klebsiella, Proteus, and Pseudomonas. Risk is increased in patients with a history of diabetes mellitus, smoking, and urinary tract hardware or manipulation. Manifestations last >3 months and typically include recurrent urinary tract infection (eg, dysuria, frequency, peritoneal discomfort), pain in the genitourinary region, and/or pain with ejaculation. Prostate examination is often normal but may show hypertrophy, tenderness, or edema. Diagnosis requires urinalysis before and after prostatic massage (or examination of expressed prostate fluid), but patients with chronic/recurrent urogenital symptoms and bacteriuria are often treated presumptively. First-line treatment is 6 weeks of a fluoroquinolone (eg, ciprofloxacin) or trimethoprim-sulfamethoxazole; patients may have recurrent symptoms if treated for shorter duration (as in this patient who received a week of treatment) (Choice D). (Choice A) CT scan of the abdomen and pelvis may be useful in men with genitourinary symptoms if initial examination and testing reveal no abnormalities. This patient with chronic urogenital symptoms and bacteriuria would likely be treated presumptively for chronic bacterial prostatitis; imaging would not be required at this time. (Choice B) A transrectal biopsy of the prostate is primarily used to evaluate for prostate cancer in patients with abnormal prostate examinations (eg, nodules, induration, asymmetry) or elevated prostate-specific antigen. This patient has signs of genitourinary infection (eg, urine leukocytes, bacteriuria) and normal prostate-specific antigen; treatment of the infection is warranted at this time. (Choice E) Tamsulosin is an alpha-1 antagonist that relaxes the smooth muscle of the bladder neck and is often used as first-line therapy for benign prostatic hyperplasia. Although frequency and urgency may be signs of benign prostatic hyperplasia, patients typically do not have pain with ejaculation, urinary leukocytes, or bacteriuria. Educational objective: Chronic bacterial prostatitis typically presents with >3 months of urinary tract infection, pain in the genitourinary region, and/or pain with ejaculation. Examination of the prostate may be normal or show hypertrophy, tenderness, or edema. Urine leukocytes and bacteriuria are typically present, particularly after prostatic massage. Treatment requires 6 weeks of a fluoroquinolone (eg, ciprofloxacin) or trimethoprim-sulfamethoxazole.

Question 18

An 8-year-old boy is brought to the physician for sore throat and fever that began yesterday.  He has no rhinorrhea, congestion, cough, or facial pain but has been complaining of abdominal pain.  He took acetaminophen with no relief of throat or abdominal pain.  The boy's past medical history is significant for 2 episodes of otitis media during infancy.  He has no medication allergies.  Physical examination shows enlarged tonsils with exudates and tender anterior cervical lymphadenopathy.  The rapid antigen test for Streptococcus pyogenes is positive.  Which of the following is the appropriate duration and rationale for treatment for this patient?

Accepted Answer

Explanation: 11ec2b69_bfbe_1a50_8f63_0d2c29804618_MD0005_00 Group A streptococcal pharyngitis is the most common bacterial pharyngitis in children and typically occurs at age 5-15. It presents with an abrupt onset of fever, sore throat, and malaise in the absence of upper respiratory symptoms (eg, cough, rhinorrhea, congestion). Classic physical examination findings include tonsillar exudates, tender anterior cervical lymphadenopathy, and palatal petechiae. Diagnosis should be confirmed with throat culture (preferred) or rapid antigen testing prior to initiation of antibiotics. Penicillin is the treatment of choice for streptococcal pharyngitis, as Streptococcus pyogenes remains very sensitive to penicillin. The benefits of antibiotic therapy include: Decreased symptom severity and duration Prevention of spread to close contacts Prevention of suppurative complications (eg, peritonsillar abscess, cervical lymphadenitis) Prevention of acute rheumatic fever Optimal duration of oral penicillin is 10 days both to ensure full eradication of bacterial carriage and to prevent rheumatic fever. Daily long-term prophylactic antibiotics are indicated for patients with a history of rheumatic fever to prevent recurrence of the disease. (Choice A) A 5-day course of oral penicillin is too short a duration to completely eradicate Group A streptococcus from the oropharynx and prevent acute rheumatic fever. On the other hand, a single dose of intramuscular penicillin is bactericidal for up to a month and can be given to patients who cannot tolerate oral antibiotics. A 5-day course of azithromycin is acceptable alternate therapy for penicillin-allergic patients. (Choices B and D) Post-streptococcal glomerulonephritis typically occurs 1-3 weeks after either a cutaneous or pharyngeal streptococcal infection. Antibiotics are effective for primary prevention of rheumatic fever, but their role in the prevention of post-streptococcal glomerulonephritis is unclear. (Choice E) Antibiotics minimize contagiousness within a day of initiating therapy, but they are continued for 10 days to prevent suppurative and nonsuppurative complications. Educational objective: The benefits of a 10-day course of penicillin for streptococcal pharyngitis include decreased symptom severity and duration, prevention of spread to close contacts, and prevention of acute rheumatic fever. References: Prevention of rheumatic fever and diagnosis and treatment of acute streptococcal pharyngitis: a scientific statement from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee of the Council on Cardiovascular Disease in the Young, the Interdisciplinary Council on Functional Genomics and Translational Biology, and the Interdisciplinary Council on Quality of Care and Outcomes Research: endorsed by the American Academy of Pediatrics. (http://www.ncbi.nlm.nih.gov/pubmed/19246689) Accuracy and precision of the signs and symptoms of streptococcal pharyngitis in children: a systematic review. (http://www.ncbi.nlm.nih.gov/pubmed/22048053) Clinical practice guideline for the diagnosis and management of group A streptococcal pharyngitis: 2012 Update by the Infectious Diseases Society of America. (http://www.ncbi.nlm.nih.gov/pubmed/22965026)

Question 19

A 32-year-old woman comes to the emergency department due to 7 days of fever and dry cough. She has also had progressive shortness of breath with minimal walking and climbing stairs. The patient was diagnosed with HIV infection a year ago and is not currently on antiretroviral treatment. She does not use tobacco, alcohol, or illicit drugs. Temperature is 38.4 C (101.1 F), blood pressure is 110/64 mm Hg, pulse is 106/min, and respiratory rate is 26/min. Pulse oxymetry is 87% on room air and decreases to 82% with minimal walking. Oropharyngeal thrush is present. Lung auscultation reveals scattered bilateral crackles and rhonchi. The abdomen is soft and nontender without organomegaly. No cyanosis, clubbing, or edema is present. Chest x-ray reveals diffuse interstitial opacities bilaterally. CD4 count is 85/mm³. The patient is admitted and started on empiric therapy. Twenty-four hours after admission, the induced sputum analysis is negative for Pneumocystis. Which of the following is the likely cause of this patient's pneumonia?

Accepted Answer

Explanation: This patient with advanced HIV has indolent pulmonary symptoms, significant hypoxia, and chest x-ray evidence of interstitial infiltrates, raising strong suspicion for Pneumocystis jirovecii pneumonia (PCP). P jirovecii is an atypical fungus that causes opportunistic pulmonary infections in those with significant immunocompromise. Patients with HIV who have CD4 counts <200/mm³ are at greatest risk and usually present with indolent fever, nonproductive cough, dyspnea, and weight loss. Profound hypoxia and tachypnea are common, and chest x-ray usually reveals bilateral interstitial or alveolar infiltrates. Patients with high pretest probability for PCP often receive empiric treatment, but definitive diagnosis requires the isolation of organisms in respiratory secretions. Induced sputum is the least invasive way to obtain respiratory samples; however, diagnostic sensitivity is 50%-90%. As such, negative results necessitate further testing if PCP is suspected. organisms (Choice A) Candida typically causes mucocutaneous infections (eg, oral thrush) in those with HIV; invasive infections are more common in patients with central venous catheter, significant neutropenia, or hospitalization in the intensive care unit. Pulmonary Candida infections usually cause airspace consolidation or cavitary lesions (not interstitial infiltrates). (Choice B) Pulmonary tuberculosis reactivation is common in those with advanced HIV and may manifest with fever, weight loss, malaise, shortness of breath, and cough. However, chest x-ray typically reveals cavitary infiltrates in the upper lobes and/or mediastinal lymphadenopathy, pleural effusion, and miliary/lobar opacities. pleural effusion (Choice D) Staphylococcus aureus pneumonia typically causes severe, rapidly progressive, necrotizing pneumonia with high fever, septic shock, and multilobar cavitary infiltrates. This patient with indolent symptoms and interstitial infiltrate is unlikely to have S aureus pneumonia. (Choice E) Streptococcus pneumoniae is the most common cause of community-acquired pneumonia and typically manifests acutely (not indolently) with fever, chills, productive cough, dyspnea, and lobar (not interstitial) infiltrate. Educational objective: Patients with HIV with CD4 counts <200/mm³ are at high risk for Pneumocystis jirovecii pneumonia (PCP). Manifestations are typically indolent with fever, dry cough, dyspnea, weight loss, hypoxia, and interstitial infiltrate on chest x-ray. Organisms can be identified on induced sputum samples in 50%-90% of cases; negative results necessitate further testing if PCP is suspected. References: Suspected Pneumocystis carinii pneumonia with a negative induced sputum examination. Is early bronchoscopy useful? (http://www.ncbi.nlm.nih.gov/pubmed/7767533)

Question 20

A 32-year-old woman comes to the emergency department due to 7 days of fever and dry cough. She has also had progressive shortness of breath with minimal walking and climbing stairs. The patient was diagnosed with HIV infection a year ago and is not currently on antiretroviral treatment. She does not use tobacco, alcohol, or illicit drugs. Temperature is 38.4 C (101.1 F), blood pressure is 110/64 mm Hg, pulse is 106/min, and respiratory rate is 26/min. Pulse oxymetry is 87% on room air and decreases to 82% with minimal walking. Oropharyngeal thrush is present. Lung auscultation reveals scattered bilateral crackles and rhonchi. The abdomen is soft and nontender without organomegaly. No cyanosis, clubbing, or edema is present. Chest x-ray reveals diffuse interstitial opacities bilaterally. CD4 count is 85/mm³. The patient is admitted and started on empiric therapy. Twenty-four hours after admission, the induced sputum analysis is negative for Pneumocystis. On day 2 of hospitalization, the patient develops worsening dyspnea and hypoxia. Repeat chest x-ray reveals worsened interstitial infiltrate. Due to significant tachypnea and poor oxygenation, the patient is intubated. The patient is currently receiving trimethoprim-sulfamethoxazole, prednisone, ceftriaxone, and azithromycin. Blood cultures from admission are negative at 48 hours. Which of the following is the best next step in management of this patient?

Accepted Answer

Explanation: 11ec2b69_bfb8_9c09_8f63_957bdf19419e_MD0005_00 This patient had respiratory decompensation on hospital day 2 after beginning empiric treatment for both Pneumocystis pneumonia (PCP) (trimethoprim-sulfamethoxazole, prednisone) and community-acquired pneumonia (ceftriaxone, azithromycin). PCP remains the most likely diagnosis in this patient with advanced HIV, indolent pulmonary symptoms, interstitial infiltrate, and respiratory decompensation following treatment (common even with concomitant corticosteroids). Given the critical nature of this patient's illness, a definitive diagnosis is now required. In patients with suspected PCP with negative induced sputum testing, the next diagnostic test of choice is a fiberscopic bronchoscopy with bronchoalveolar lavage. This test is highly sensitive (90%-100%) for diagnosis of PCP. Therefore, a negative result would make PCP extremely unlikely, suggesting the need to evaluate for other etiologies. A positive result would confirm the diagnosis in this critically ill patient. Bronchoalveolar lavage fluid could also be sent for studies evaluating for other respiratory pathogens or causes of respiratory decompensation. (Choice B) A definitive diagnosis is important due to the clinical severity of this case and the fact that up to 15% of patients with PCP have a concurrent pulmonary illness (eg, Mycobacterium tuberculosis). Clinical observation alone would not be prudent. (Choice C) High-resolution CT scan is likely to show evidence of PCP (eg, ground glass opacities) but is unlikely to provide a definitive diagnosis. PCP diagnosis requires the isolation of organisms in respiratory samples. (Choice D) Repeat blood cultures are not likely to provide a diagnosis as admission blood cultures are negative, PCP is the most likely diagnosis (AIDS, indolent pulmonary symptoms, interstitial infiltrate), and Pneumocystis jirovecii is not culturable. (Choice E) A transthoracic echocardiogram could help evaluate whether ventricular dysfunction was causing pulmonary edema with resultant respiratory decompensation and worsening pulmonary infiltrate. However, this patient had no evidence of volume overload (eg, edema) on admission and has several features (fever, immunocompromise) suggesting an infectious process. Infectious endocarditis with septic pulmonary emboli is also less likely in this patient with negative blood cultures and interstitial infiltrate. Educational objective: Patients with suspected Pneumocystis pneumonia require fiberscopic bronchoscopy with bronchoalveolar lavage if induced sputum samples do not yield a diagnosis.

Exam 1: Advanced Clinical Medicine