Question 1

A 44-year-old man with HIV infection is evaluated for persistent fevers, progressive generalized fatigue, poor appetite, and marked weight loss over the last 2 months.  He has no chest pain or shortness of breath.  He has been noncompliant with antiretroviral therapy, and his last CD4 count 6 months ago was 90/µL.
His temperature is 38.3 C (101 F), blood pressure is 91/53 mm Hg, pulse is 105/min, and respirations are 21/min.  Examination shows a pale conjunctiva and dry mucous membranes.
Laboratory results are as follows:

A CT scan of the chest and abdomen reveals lucencies in the skeleton and bulky mediastinal and abdominal lymphadenopathy.
Bone marrow biopsy in this patient would most likely show which of the following?

Accepted Answer

With this patient's poorly controlled HIV status, marked body cavity lymphadenopathy, and bone lucency, the most likely underlying cause is non-Hodgkin lymphoma (NHL). Around 4% of HIV patients have lymphoma at the time of diagnosis with the same percentage developing lymphoma during their disease course. Factors that contribute to the incidence include direct effects of HIV, immunosuppressive state, co-infection with other oncogenic viruses (eg, Epstein-Barr), and environmental oncogenic stimuli. HAART prevents severe immunosuppression, which in turn helps to decrease the incidence of NHL. Patients with NHL tend to present with B symptoms (fever, weight loss, and night sweats), extranodal disease, and involvement of unusual locations (eg, body cavity, rectum, and soft tissue). Rarely, they may present with fever of unknown origin. Diffuse large-cell NHL and Burkitt lymphoma are the most common AIDS-related lymphomas. (Choice A) Chronic lymphocytic leukemia is not associated with HIV infection and the blood count differential shows predominantly mature-appearing lymphocytes. (Choice B) Fungal infections such as blastomycosis and histoplasmosis can involve bone. However, this patient's bulky lymphadenopathy is more suggestive of a lymphoma. (Choice C) Kaposi sarcoma usually presents with skin lesions (purplish, reddish blue, or dark brown/black) on the lower extremities, often associated with lymphedema. Lymph node involvement occurs infrequently. Kaposi sarcoma (Choice D) Although myeloma can cause bone lesions, it does not cause bulky lymphadenopathy and severe B symptoms. Educational objective: AIDS-related lymphomas are common in patients with advanced HIV, a low CD4 count (<100/µL), high HIV viral load, and a prior diagnosis of AIDS. Patients with non-Hodgkin lymphoma (NHL) tend to present with B symptoms, extranodal disease, and involvement of unusual locations. Diffuse large-cell NHL and Burkitt lymphoma are the most common AIDS-related lymphomas. __________ References: How I treat HIV-associated lymphoma. (http://www.ncbi.nlm.nih.gov/pubmed/22337719)

Question 2

A 50-year-old man comes to the physician with complaints of low-grade fever, malaise, and intermittent diarrhea.  He experiences a burning sensation in his chest when he swallows food.  He received a living related-donor kidney transplant 5 months ago.  The donor and recipient were both cytomegalovirus immunoglobulin G antibody positive and Epstein-Barr virus antibody positive.  Valganciclovir prophylaxis was given for 100 days.  The patient experienced an acute cellular rejection 3 weeks ago that was diagnosed after kidney biopsy.  He was treated with pulse methylprednisolone and a change from cyclosporine to tacrolimus.  His rejection was successfully treated and his kidney function stabilized.
On examination, the patient is in no distress.  His temperature is 38.1 C (100.5 F), blood pressure is 120/70 mm Hg, pulse is 90/min, and respirations are 16/min.  Pulse oximetry is 97% on room air.  Ocular fundi show no exudates or papilledema.  The remainder of his physical examination is within normal limits.
Laboratory results are as follows:

A chest x-ray is normal and unchanged from a pre-transplant film.
Which of the following is the most likely explanation for this patient's illness?

Accepted Answer

11ec193a_9858_da40_853d_77b0e91a37ba_MD0002_00 This patient most likely has cytomegalovirus (CMV) disease. CMV infection is defined as detection of CMV antibodies, antigen, DNA, or virus without significant clinical symptoms. CMV disease is usually associated with a rejection episode and increased immunosuppression. Patients typically develop a mononucleosis-like illness with low-grade fever, malaise, leukopenia, and some degree of organ involvement (eg, hepatitis, pancreatitis, colitis, meningoencephalitis, and pneumonitis). CMV eye disease is more common in HIV than organ transplant patients. CMV disease is more common in CMV-positive donors and CMV-positive recipients. Several strains of cytomegalovirus do not confer cross-immunity. Recipients may have reactivation of existing virus or superinfection with a new donor viral strain. This patient was appropriately treated with valgancicyclovir (preferred prophylactic for CMV) for the first 3 months following transplantation but had organ rejection with a change in immunosuppression. Treatment usually involves immunosuppression reduction and antiviral therapy (eg, ganciclovir) for more severe disease. However, cyclosporine or tacrolimus is not discontinued unless there is life-threatening disease. (Choice A) BK viral infection occurs in about 5% of renal transplant recipients and usually presents with tubulointerstitial nephritis and occasional ureteric stenosis. Most centers monitor patients with periodic BK-PCR or acute organ dysfunction up to a few years post transplantation. Kidney biopsy usually shows the characteristic findings for BK involvement, which were not seen in this patient. (Choice C) Herpes simplex reactivation commonly occurs in the first months after solid organ transplantation and may present with oral/genital lesions, esophagitis, pneumonitis, hepatitis, and encephalitis. This patient's illness is not typical for herpes simplex infection. (Choice D) Tacrolimus toxicity usually presents with acute nephrotoxicity, hypertension, neurotoxicity (eg, tremor), and metabolic disturbances (eg, glucose intolerance). This patient's absence of hypertension and nephrotoxicity makes this less likely. (Choice E) Toxoplasma gondii infection rarely occurs following renal transplantation and presents with lymphadenopathy, hepatosplenomegaly, pneumonitis, myocarditis, brain abscess, and chorioretinitis. Absence of these findings in this patient makes Toxoplasma infection less likely. Educational objective: Cytomegalovirus (CMV) disease commonly occurs in the first few months after solid organ transplantation. Infection is defined as CMV viral isolation, and disease is defined as clinical symptoms (eg, mononucleosis-like syndrome) with organ involvement (eg, hepatitis, colitis, and pneumonitis). Treatment involves immunosuppression reduction and antiviral therapy (eg, ganciclovir) for more severe disease. __________ References: Viral infection in the renal transplant recipient. (http://www.ncbi.nlm.nih.gov/pubmed/15829710) International consensus guidelines on the management of cytomegalovirus in solid organ transplantation. (http://www.ncbi.nlm.nih.gov/pubmed/20224515)

Question 3

A 47-year-old previously healthy man comes to the office due to 3 days of abdominal discomfort, nausea, and diarrhea.  He has had 10-12 small-volume stools per day with no visible blood or mucus.  He has had no fever or vomiting but did have generalized aches and a sense of being unwell prior to the onset of diarrhea.  The patient has not taken any antibiotics or traveled recently.  He ate at an outdoor cookout 2 days before he developed symptoms.
Vital signs are within normal limits with no orthostatic changes.  Examination shows moist mucous membranes.  Mild periumbilical tenderness is present with no guarding or rebound tenderness.  Bowel sounds are increased.  Rectal examination reveals no blood.
Which of the following is the most likely cause of this patient's symptoms?

Accepted Answer

11ec193a_9860_f09b_853d_e9c5f0bc81c3_MD0002_00 This patient who ate at an outdoor cookout developed frequent, small-volume stools several days later, raising strong suspicion for inflammatory diarrhea due to a foodborne illness. Inflammatory diarrhea is usually due to infection with Campylobacter, Shigella, or Salmonella. These pathogens invade the large bowel and result in abrupt-onset, crampy abdominal pain and frequent small-volume diarrhea several days after consumption. Blood and mucus are often (but not always) present in the stool. There may also be an associated febrile prodrome with nausea and vomiting. With the exception of enterohemorrhagic Escherichia coli (EHEC), most cases of inflammatory diarrhea are mild and self-limited. By contrast, noninflammatory diarrhea is usually due to the ingestion of enterotoxin-producing bacteria. Most cases affect the small bowel and lead to large-volume watery diarrhea with or without nausea, vomiting, abdominal cramps, and bloating. Fever is rarely present. Noninflammatory diarrhea is most commonly due to Clostridium perfringens and enterotoxigenic E coli (Choice B). (Choice C) Norovirus infection typically presents with headache, myalgias, acute-onset vomiting, and diarrhea (nonbloody with loose or watery stools). Symptoms usually resolve within 72 hours with full recovery. (Choice D) EHEC produces Shiga toxin and is typically transmitted by the consumption of undercooked ground beef. Manifestations include hemorrhagic colitis and, in 10%-15% of cases, hemolytic uremic syndrome. This patient had no blood in his stool or rectal vault, making EHEC less likely than Campylobacter. (Choice E) Staphylococcus aureus foodborne illness is due to the ingestion of preformed toxins and presents with sudden-onset nausea and vomiting 1-6 hours after consumption. Diarrhea and fever can occasionally occur. Educational objective: Inflammatory diarrhea usually originates in the large bowel and presents with small-volume, frequent diarrhea; possible febrile prodrome; and possible blood or mucus in the stool. Noninflammatory diarrhea originates in the small bowel and usually presents with large-volume, watery diarrhea. Organisms with preformed toxins typically cause sudden-onset nausea and vomiting 1-6 hours after ingestion without significant diarrhea. __________ References: Clinical features of sporadic Campylobacter infections in Norway. (http://www.ncbi.nlm.nih.gov/pubmed/1287808) Campylobacter enteritis: clinical and epidemiologic features. (http://www.ncbi.nlm.nih.gov/pubmed/380433)

Question 4

A 78-year-old woman comes to the urgent care center due to the abrupt onset of fever, sore throat, a nonproductive cough, and muscle pain that began yesterday morning.  Several of her social friends have been sick, including one who was hospitalized with influenza.  The patient received an influenza vaccine 2 months ago and has no history of influenza infection.  Medical history includes hypertension, coronary artery disease, and ischemic cardiomyopathy with a left ventricular ejection fraction of 35%.  She is a lifetime nonsmoker.
Temperature is 38.3 C (100.9 F), blood pressure is 122/76 mm Hg, pulse is 95/min, and respirations are 14/min.  Oxygen saturation is 98% on room air.  The patient appears uncomfortable but is in no acute distress.  No pharyngeal erythema or tonsillar exudates are present, and there is no cervical lymphadenopathy.  Auscultation of the lungs reveals no abnormalities.
Rapid influenza antigen test is negative, and chest x-ray reveals no infiltrates.  The patient asks to go home.
Which of the following is the most reasonable next step in management of this patient?

Accepted Answer

This patient who had exposure to an individual with influenza now has acute fever, sore throat, cough, and malaise, raising strong suspicion for influenza infection. Rapid influenza antigen testing cannot be used to rule out infection due to high false-negative rates (pooled sensitivity is only ~65%). Similarly, a history of influenza vaccination does not eliminate the risk of infection; vaccination is protective in only 45%-60% of older individuals, and outbreaks commonly occur even in highly vaccinated populations (eg, assisted living, nursing home). Patients who have influenza symptoms for <48 hours should receive antiviral therapy with oseltamivir or zanamivir to reduce symptom duration and, potentially, the likelihood of influenza-related complications (eg, secondary pneumonia). Antiviral therapy, regardless of symptom duration, is recommended for patients who require hospitalization, have severe or progressive illness, or are at high risk of complications. high risk (Choice A) Although the diagnosis of influenza can be confirmed by reverse transcription PCR or viral culture (the latter takes 48-72 for results and is used less commonly), antiviral treatment should not be delayed for confirmatory testing. (Choice B) This patient with a cough and no tonsillar exudates or cervical lymphadenopathy has only 1 of the Centor criteria (fever), indicating no need for rapid streptococcal antigen testing due to a low likelihood of streptococcal infection. Centor criteria (Choice C) This patient with a normal chest x-ray and a nonproductive cough is unlikely to have community-acquired pneumonia; treatment with azithromycin is not indicated at this time. (Choice E) Symptomatic treatment is indicated for low-risk patients who have had influenza symptoms >48 hours. This patient has had symptoms <48 hours and also has risk factors (ie, advanced age, cardiac disease) for influenza complications; she should receive antiviral therapy. Educational objective: Antiviral treatment (eg, oseltamivir) is recommended for patients with <48 hours of influenza-like symptoms. Those who require hospitalization, have severe or progressive illness, or are at high risk of complications should also receive antiviral therapy regardless of symptom duration. Negative rapid influenza antigen testing or a history of influenza vaccination does not rule out influenza infection. __________ References: Antiviral agents for the treatment and chemoprophylaxis of influenza --- recommendations of the Advisory Committee on Immunization Practices (ACIP). (http://www.ncbi.nlm.nih.gov/pubmed/21248682) Seasonal influenza in adults and children--diagnosis, treatment, chemoprophylaxis, and institutional outbreak management: clinical practice guidelines of the Infectious Diseases Society of America. (http://www.ncbi.nlm.nih.gov/pubmed/19281331)

Question 5

A 37-year-old man comes to the physician with nodules on his hand and forearm.  The nodules first appeared about 2 weeks ago on the dorsal aspect of his right index finger.  Initially, a small papule formed and drained some clear, odorless material.  There was minimal associated pain.  The nodule persisted and several days later two other similar nodules formed over the dorsal aspect of his right wrist and distal arm.  He has no fever, chills, or constitutional symptoms.  The patient works as a landscaper and has installed a lot of moss in terraced yards over the past month.  He also hunts and within the past month has dressed rabbits that he has shot.  He is in good health, takes no medications, and has no HIV risk factors.
Vital signs are normal.  Cardiopulmonary, abdominal, and neurologic examinations are normal.  There are 3 tender papules on top of the dorsal aspects of the right index finger, wrist, and the distal right upper extremity.  One open nodule has a small crust on the top.  There are no other cutaneous lesions and no adenopathy.
A sample is obtained for biopsy and culture.  The biopsy shows mixed pyogenic and granulomatous inflammation.  Gram stain, acid-fast/partial acid-fast, silver methenamine, and periodic acid-Schiff stains (PAD) are negative.  Cultures are pending.
What is the most likely diagnosis in this patient?

Accepted Answer

This patient most likely has the lymphocutaneous form of sporotrichosis. Sporotrichosis is a subacute to chronic infection caused by the dimorphic fungus Sporothrix schenckii, whose natural habitat is on the bark of trees, shrubs, and garden plants, and on plant debris in soil. Lymphocutaneous sporotrichosis is the most commonly encountered form of sporotrichosis, with the typical host being a healthy individual with an outdoor hobby or occupation (eg, landscaping, rose gardening). Lymphocutaneous sporotrichosis begins with inoculation of contaminated moss, soil, or other organic material into the skin or subcutaneous tissue. Days to weeks later, a reddish nodule forms at the site of inoculation (eg, thorn prick). This primary lesion typically ulcerates but can remain nodular. Drainage from the lesion is not grossly purulent and has no odor. Adenopathy and systemic signs of infection are also usually absent. Similar lesions subsequently develop more proximately and follow a lymphatic chain (referred to as nodular lymphangitis). Biopsies typically show a mixed pyogenic and granulomatous inflammation. Fungal stains (silver methenamine silver, PAD) are often negative because the number of infecting organisms is frequently small. Culture is the gold standard for establishing a diagnosis of sporotrichosis. Itraconazole is the drug of choice for treatment. (Choice A) Mycobacterium marinum infection often follows abrasions to an extremity that occur in nonchlorinated water ("fish tank granuloma"). Fishermen, oyster handlers, swimmers, and aquarium workers are predisposed to infection. Clinical presentation can be similar to sporotrichosis. Microscopic examination shows acid-fast organisms. (Choice B) Although rare, a lymphocutaneous form of Nocardia infection (particularly with Nocardia brasiliensis) can affect immunocompetent hosts and results from direct inoculation of the organism into the skin following traumatic injury. Referred to as sporotrichoid nocardiosis, it can closely resemble sporotrichosis. Diagnosis of Nocardia infection is difficult; however, a presumptive diagnosis can be made if partially acid-fast, filamentous, branching rods are seen in clinical specimens. (Choice C) Pyoderma gangrenosum (PG) usually occurs within the context of a systemic disorder, most commonly inflammatory bowel disease, arthropathies, and hematologic malignancies. The most frequent presentation of ulcerative pyoderma gangrenosum is a rapidly developing, painful, purulent ulcer with a violaceous and undermined border. Fever may also be present. Pyoderma gangrenosum (PG) (Choice E) The majority of patients with tularemia present with ulceroglandular disease. Patients typically report recent handling of animals (eg, rabbits) or exposure to ticks. Affected patients usually present with fever and a single erythematous papulo-ulcerative lesion with a central eschar. The skin lesion is accompanied by tender regional lymphadenopathy. Nodular lymphangitis is a rare manifestation of tularemia. Educational objective: The initial lesion of lymphocutaneous sporotrichosis is a reddish nodule that later ulcerates and appears at the site of a thorn prick or other skin injury. From the site of inoculation, the fungus spreads along the lymphatics forming additional subcutaneous nodules and ulcers. Definitive diagnosis is made by culture, and itraconazole is the drug of choice for treatment. __________ References: Sporothrix schenckii and sporotrichosis. (http://www.ncbi.nlm.nih.gov/pubmed/21976602)

Question 6

A 27-year-old woman comes to the outpatient clinic for evaluation.  She says her father, who came from India 3 months ago and is living with her, was recently diagnosed with pulmonary tuberculosis and began a 4-drug treatment regimen.  The patient has had no cough, weight loss, night sweats, chills, or fevers.  She has a history of type 1 diabetes mellitus but no history of lung disease.  She does not use tobacco, alcohol, or illicit drugs.
Vital signs are within normal limits.  Cardiac and pulmonary examinations are normal.  A tuberculin skin test is read 48 hours later as 7-mm induration and 12-mm erythema.  Chest x-ray shows no abnormalities.
What is the best next step in management of this patient?

Accepted Answer

11ec193a_985c_aad5_853d_bd4f23af28c4_MD0002_00 Close contacts of individuals with active pulmonary tuberculosis (TB) must be screened for TB exposure. In this population, a tuberculin skin test (TST) reaction of ≥5-mm induration is considered positive. Patients with positive screening then require chest x-ray and symptom review to differentiate between latent and active disease. ≥5-mm induration This patient has a positive TST with no symptoms or chest x-ray findings, indicating latent TB infection (LTBI). Several LTBI treatment regimens are available; short-course (eg, 3-4 months), rifamycin-based regimens (eg, 3 months of weekly isoniazid [INH] plus rifapentine; 4 months of daily rifampin; 3 months of daily INH plus rifampin) are preferred over daily INH for 6-9 months. Some patients need to be on prolonged, daily INH therapy due to drug-drug interactions or hypersensitivity to rifampin; major side effects of INH therapy include: Peripheral neuropathy - can be prevented by pyridoxine supplementation. However, pyridoxine should only be added for those at greatest risk including patients who are pregnant, those who have other conditions associated with neuropathy (eg, diabetes, uremia, alcohol use disorder, HIV), and individuals with seizure disorder.Hepatitis - cannot be prevented with pyridoxine supplementation. Patients should be advised to abstain from alcohol. Liver function tests should be monitored at baseline and every 3 months. INH should be discontinued immediately if serum transaminase levels are >3 times the normal limit in symptomatic patients or >5 times the normal limit in asymptomatic patients. Peripheral neuropathy - can be prevented by pyridoxine supplementation. However, pyridoxine should only be added for those at greatest risk including patients who are pregnant, those who have other conditions associated with neuropathy (eg, diabetes, uremia, alcohol use disorder, HIV), and individuals with seizure disorder. Peripheral neuropathy - can be prevented by pyridoxine supplementation. However, pyridoxine should only be added for those at greatest risk including patients who are pregnant, those who have other conditions associated with neuropathy (eg, diabetes, uremia, alcohol use disorder, HIV), and individuals with seizure disorder. Hepatitis - cannot be prevented with pyridoxine supplementation. Patients should be advised to abstain from alcohol. Liver function tests should be monitored at baseline and every 3 months. INH should be discontinued immediately if serum transaminase levels are >3 times the normal limit in symptomatic patients or >5 times the normal limit in asymptomatic patients. Hepatitis - cannot be prevented with pyridoxine supplementation. Patients should be advised to abstain from alcohol. Liver function tests should be monitored at baseline and every 3 months. INH should be discontinued immediately if serum transaminase levels are >3 times the normal limit in symptomatic patients or >5 times the normal limit in asymptomatic patients. (Choice A) Patients with positive TB screening who have symptoms or chest x-ray findings concerning for active TB require further evaluation with sputum samples for acid-fast bacillus and mycobacterial culture. This patient has a normal chest x-ray and no symptoms. (Choice C) TST induration ≥5 mm is considered a positive result in close contacts of a known TB case. The 10-mm cut-off is used for recent immigrants from endemic areas, injection drug users, residents/employees of high-risk settings, and those at greater risk for TB reactivation (eg, prolonged glucocorticoid use, leukemia, end-stage renal disease). (Choice D) A positive TST indicates exposure and does not need to be repeated. Close contacts who have a negative initial TST should have a repeat TST done at 8-12 weeks. (Choice E) The combination of rifampin and pyrazinamide was shown to result in severe liver injury and is no longer recommended as treatment. Educational objective: A tuberculin skin test reaction of ≥5 mm is considered positive in a patient with recent exposure to an individual with active pulmonary tuberculosis. Short-course, rifamycin-based regimens are recommended as treatment for latent tuberculosis infection. __________ References: Current concepts in the management of tuberculosis. (http://www.ncbi.nlm.nih.gov/pubmed/21454737)

Question 7

A 22-year-old man living in Connecticut comes to the physician after finding a tick on his shoulder this morning.  He cleared brush and mowed the lawn in his backyard yesterday morning.  Before yesterday, he does not recall spending any prolonged time outdoors in the past 2 weeks.
The patient's temperature is 37.4 C (99 F), blood pressure is 112/72 mm Hg, pulse is 84/min, and respirations are 14/min.  He is comfortable but anxious.  There are no skin rashes.  On his left shoulder, there is an attached 1.5 mm-long brown tick.  The tick is removed carefully using forceps and the area is disinfected.  No remnants of the tick are observed on the skin following removal.
Which of the following would be an appropriate next step in management?

Accepted Answer

11ec193a_985b_4b43_853d_c9c76403dc6a_MD0002_00 Lyme disease is caused by Borrelia burgdorferi in the United States and usually presents initially with erythema migrans (EM). However, the infection is typically not transmitted in the first 48-72 hours of tick attachment. Infection risk is increased with tick engorgement and/or attachment for > 36 hours. The first step is tick removal, which is best done with tweezers or protected hands by pulling straight up. Antibiotic prophylaxis is recommended in patients meeting all 5 of the criteria in the Table, usually with doxycycline 200 mg in a single dose. If the patient cannot take (or refuses) doxycycline, most physicians do not advise prophylaxis with another antibiotic. Instead, observation is recommended with rapid treatment if EM develops. This patient is asymptomatic, has tick attachment for < 36 hours, and needs just reassurance with follow-up as the next step (Choices A and B). (Choice C) IgM antibodies for Lyme disease may take 2-6 weeks after infection to appear in the blood. Serologic testing (eg, ELISA followed by Western blot) in asymptomatic tick bites in the first 2 weeks may lead to false negatives and is usually not recommended. However, patients presenting initially with EM do not require serologic testing and should be treated for Lyme disease with antibiotics (eg, doxycycline, cefuroxime, or amoxicillin). (Choice E) Polymerase chain reaction testing of the tick is commercially available, but the clinical utility is low as duration of attachment determines transmission risk more than the tick's infection status. Educational objective: The risk of Borrelia burgdorferi transmission increases in the first 48-72 hours after tick attachment and usually does not require treatment in asymptomatic patients. Antibiotic prophylaxis with doxycycline 200 mg in a single dose is recommended for patients meeting all 5 criteria (eg, > 36 hours of engorged tick attachment in an endemic area). __________ References: Diagnosis and treatment of Lyme disease. (http://www.ncbi.nlm.nih.gov/pubmed/18452688) Prophylaxis with single-dose doxycycline for the prevention of Lyme disease after an Ixodes scapularis tick bite. (http://www.ncbi.nlm.nih.gov/pubmed/11450675)

Question 8

A 64-year-old woman comes to the emergency department with a 3-day history of intermittent fever, cough with blood-tinged sputum, night sweats, and generalized malaise.  She also reports right-sided chest pain on deep inspiration over the last 24 hours.  The patient was diagnosed with breast cancer and is undergoing combination chemotherapy.  Her other medical problems include moderate chronic obstructive pulmonary disease and hypothyroidism.
Her temperature is 38.2 C (100.8 F), blood pressure is 107/64 mm Hg, pulse is 110/min, and respirations are 18/min.  Pulse oximetry is 93% on room air.  Physical examination is notable for pale conjunctiva.  Lung examination shows scattered rhonchi, and cardiac examination is significant for tachycardia without murmurs.  The abdomen is soft and nontender without organomegaly.  There are no skin rashes.
Laboratory results are as follows:

The patient is started on vancomycin and piperacillin/tazobactam and fails to improve clinically after 3 days of treatment.  Computed tomography scan of the chest shows several small (1-2 cm) nodular lesions scattered throughout the lung with surrounding ground-glass attenuation.
Blood and sputum cultures are negative, and bronchoscopy and bronchoalveolar lavage are performed for cultures and cytology.
Which of the following is the best next step in management of this patient?

Accepted Answer

11ec193a_9862_502e_853d_d3eda0b2e11b_MD0002_00 This patient most likely has invasive pulmonary aspergillosis (IPA). Aspergillus has diverse presentations, including asymptomatic infection in immunocompetent hosts, allergic bronchopulmonary aspergillosis (ABPA) in patients with asthma or cystic fibrosis, and various patterns of chronic PA. Risk factors for chronic PA include prior lung disease such as pulmonary tuberculosis, ABPA, lung cancer, chronic obstructive pulmonary disease, and sarcoidosis. Symptoms of IPA are nonspecific and usually mimic bronchopneumonia: fever unresponsive to antibiotics, cough, sputum production, and dyspnea. Patients may also present with pleuritic chest pain (due to vascular invasion leading to thromboses that cause small pulmonary infarcts) and hemoptysis, which is usually mild. IPA is one of the most common causes of hemoptysis in neutropenic patients. Chest x-ray may not detect early-stage disease (ie, small nodules). Chest computed tomography (CT) scan shows single or multiple nodules with or without cavitations and "halo sign" (nodules surrounded by ground-glass infiltrates). Diagnosis is suggested by culture and histology. Enzyme-linked immunosorbent assay on serum or bronchoalveolar lavage fluid can be used to detect galactomannan antigen (present in Aspergillus cell walls), especially in patients with hematologic malignancies. Voriconazole has become the gold standard as primary therapy for invasive aspergillosis. Voriconazole was more effective than amphotericin B as initial therapy for IPA and was associated with significantly improved survival (71% vs 58%, respectively) in a randomized trial (Choice A). (Choice B) High-dose intravenous corticosteroids are not recommended for treating invasive aspergillosis due to the risk of further immunosuppression and worsening disease spread. Oral steroids are used in the treatment of ABPA. (Choice C) This patient's presentation (eg, severe neutropenia, chest CT scan with halo sign) is more suggestive of IPA than pulmonary tuberculosis. (Choice D) This patient has not shown clinical improvement with vancomycin and has negative bacterial cultures; linezolid is unlikely to be of much help. Educational objective: Invasive pulmonary aspergillosis occurs in severely immunocompromised patients. Diagnosis is made by chest computed tomography scan (nodules with or without cavitations surrounded by ground-glass infiltrates), culture, histopathology, or enzyme-linked immunosorbent assay for galactomannan antigen. Voriconazole is the preferred treatment. __________ References: Pulmonary aspergillosis: a clinical update. (http://www.ncbi.nlm.nih.gov/pubmed/17525130) Pulmonary aspergillosis: clinical presentation, diagnostic tests, management and complications. (http://www.ncbi.nlm.nih.gov/pubmed/20375786)

Question 9

A 34-year-old immigrant from Brazil comes to the physician with 2 months of palpitations accompanied by lightheadedness.  He also complains of mild shortness of breath.  The patient suffers from moderate, persistent asthma and takes daily inhaled glucocorticoid and salmeterol.  He received "most of the childhood immunizations."  He has no family history of heart disease or sudden cardiac death.
The patient's blood pressure is 122/70 mm Hg and pulse is 82/min.  Estimated jugular venous pressure is normal.  The apical impulse is displaced to the left.  A soft 2/6 holosystolic murmur is heard at the apex.  Lungs are clear on auscultation.  There is no organomegaly, skin rash, or peripheral edema.
Electrocardiogram shows normal sinus rhythm with right bundle branch block.  Echocardiogram shows a left ventricular apical aneurysm and left ventricular ejection fraction of 35%.  Cardiac catheterization shows normal coronary arteries.
Which of the following is most likely responsible for this patient's condition?

Accepted Answer

This patient has the classic clinical presentation of chronic Chagas cardiomyopathy, which is caused by a protozoan infection from Trypanosoma cruzi. The natural history of Chagas disease has 3 distinct phases. The first is an acute phase of mild, nonspecific symptoms with fever or myalgias, followed by an indeterminate phase with serologic or parasitic evidence of T cruzi infection in the absence of symptoms or signs of infection. The final phase is chronic Chagas cardiomyopathy. Chronic Chagas cardiomyopathy is the leading cause of dilated cardiomyopathy in Central and South America. Patients can remain asymptomatic for several years or develop symptoms of heart failure. Echocardiogram shows varying degrees of right and/or left ventricular systolic dysfunction, along with left ventricular apical aneurysm, which is considered pathognomonic of Chagas cardiomyopathy. (Choice A) Blastomycosis is a systemic granulomatous infection usually involving the lungs that causes acute or chronic pneumonia. It can also involve extrapulmonary sites including skin (verrucous lesions, subcutaneous nodules), bone (osteomyelitis), and the genitourinary tract (prostatitis, epididymo-orchitis). (Choice B) Lyme carditis caused by disseminated Borrelia burgdorferi typically presents with atrioventricular conduction block. Cardiomyopathy is extremely rare and has not been reported in the United States. (Choice C) Dengue virus infection has degrees of clinical presentation ranging from a mild self-limiting febrile illness to dengue hemorrhagic fever with shock syndrome. Chronic cardiomyopathy is not seen with Dengue fever. (Choice D) Leishmania donovani causes visceral leishmaniasis (also known as kala-azar), which is characterized by insidious onset and progression of fever, malaise, weight loss, and splenomegaly. Educational objective: Chagas disease is the leading cause of dilated cardiomyopathy in Central and South America. It is caused by Trypanosoma cruzi infection and is characterized by myocarditis progressing to dilated cardiomyopathy, nonspecific electrocardiogram abnormalities including right bundle branch block and left anterior fascicular block, and development of left ventricular apical aneurysms. __________ References: Chagas disease: an overview of clinical and epidemiological aspects. (http://www.ncbi.nlm.nih.gov/pubmed/23770163)

Question 10

A 24-year-old woman is being evaluated for positive reactive plasma reagin (RPR) testing for syphilis as part of a routine prenatal workup.  The current titer is 1:8.  She feels well and has no complaints.  Six months ago, she went to the hospital with fever and a diffuse rash following sexual activity with a new male partner.  There she underwent testing that showed an RPR titer of 1:256.  The Treponema pallidum particle agglutination assay was positive at that time.  HIV testing was negative.  The patient was treated for secondary syphilis with intramuscular penicillin G.  Her symptoms resolved over the next week.  Her partner also was treated appropriately for syphilis at that time; she has had no new sexual partners.
Complete examination, including genital and neurologic examination, is normal.  Repeat HIV antibody testing is negative.
What is the best next step in management of this patient?

Accepted Answer

This patient was diagnosed with secondary syphilis before pregnancy and was treated appropriately with a dose of penicillin G. Repeat nontreponemal serologic testing 6 months later showed a significantly decreased, but still positive, reactive plasma reagin (RPR). There are 3 possible reasons for persistently positive nontreponemal testing: Inadequate or inappropriate treatment (failure of RPR to fall 4-fold within 6-12 months of treatment)ReinfectionSerofast reaction Inadequate or inappropriate treatment (failure of RPR to fall 4-fold within 6-12 months of treatment) Reinfection Serofast reaction This patient's titer decreased by over 4-fold, making inadequate treatment unlikely. She has no new symptoms, her partner also was treated appropriately, and she has no new partners, so reinfection is unlikely. In some patients, a low (serofast) titer may remain positive indefinitely after the initial 4-fold decline. The most appropriate strategy is to repeat testing in 6 months to ensure that the titer is stable and not rising, which would suggest reinfection. 11ec193a_9863_619f_853d_55d921c2f295_MD0002_00 (Choice A) Intramuscular penicillin is the appropriate treatment for primary, secondary, or latent syphilis. However, this patient was adequately treated for secondary syphilis, experienced an appropriate fall in titers, and has no symptoms or history suggestive of a new infection. (Choices B and C) Intravenous penicillin is the treatment for neurosyphilis, which may explain inadequate treatment in some patients. A lumbar puncture is warranted to establish the diagnosis. However, this patient had no neurologic symptoms and the RPR titer decreased as anticipated. (Choice E) Repeating the specific treponemal test, such as a Treponemal pallidum particle agglutination or fluorescent treponemal antibody-absorption test, is not indicated as these antibodies usually remain positive for life following infection. Educational objective: In HIV-negative patients treated for syphilis, repeat nontreponemal testing should be performed at 6 and 12 months to document response. A serofast response should be considered in patients who have a 4-fold decrease in titers but a persistently positive, low-level titer despite treatment. __________ References: Syphilis: a reemerging infection. (http://www.ncbi.nlm.nih.gov/pubmed/22963062) Update on syphilis: resurgence of an old problem. (http://www.ncbi.nlm.nih.gov/pubmed/13129993)

Question 11

A 40-year-old man comes to the physician with pain, swelling, warmth, and redness of his distal right lower extremity for the past 3 days. No recent trauma has occurred to the area. He had a similar episode 1 year ago in his right leg and was hospitalized for cellulitis, which responded quickly to antibiotics. He has no previous history of lower-extremity edema or recurrent infections. The patient exercises at a gym 3 times a week. He does not use tobacco or illicit drugs and works as an accountant. Vital signs are within normal limits. BMI is 32 kg/m². Examination shows swelling, warmth, and erythema of his right lower extremity starting from his foot up to the mid-calf region. There is also erythema in the 1st and 2nd toe web spaces with chronic-appearing skin erosions. There is no purulent drainage or ulcers. Pulses are 2+ in the bilateral lower extremities. In addition to treatment of his cellulitis, which of the following is the best next step in management of this patient?

Accepted Answer

11ec193a_985f_df28_853d_2714605704e3_MD0002_00 Recurrent cellulitis can occur in up to 30% of patients after an initial episode and is usually due to lymphatic stasis or skin barrier breakdown. This patient's erythema in the toe web spaces is most consistent with tinea pedis. Tinea pedis can cause skin breakdown between the toes and is a potential site for bacterial entry in this small area often overlooked by clinicians. The bacteria can then spread to adjacent tissues to cause cellulitis. As a result, treating this patient's underlying tinea pedis may decrease future episodes of ipsilateral cellulitis. (Choices A and B) Limited studies suggest that prophylactic antibiotics may reduce recurrent cellulitis in patients with > 2 episodes over a 6-month period or with untreatable predisposing factors (eg, abnormal anatomy due to lymph node dissection, large hemangioma, or congenital malformations). (Choice C) Skin biopsy would be indicated if the cellulitis does not respond to usual antibiotic therapy. (Choice E) Obesity may be associated with recurrent cellulitis due to increased hydrostatic pressure from lower-extremity venous stasis or lymphatic stasis. However, this patient should first be treated for his obvious tinea infection that is causing recurrent cellulitis in the same leg. Educational objective: Recurrent cellulitis can occur in up to 30% of patients after an initial episode and is usually due to lymphatic stasis or skin barrier breakdown. Tinea pedis can cause skin breakdown between the toes and is a potential site for bacterial entry in this small area often overlooked by clinicians. Treatment of underlying tinea pedis can decrease the incidence of recurrent episodes of ipsilateral cellulitis. __________ References: Lower limb cellulitis and its mimics: part I. lower limb cellulitis. (http://www.ncbi.nlm.nih.gov/pubmed/22794815) Association of athlete's foot with cellulitis of the lower extremities: diagnostic value of bacterial cultures of ipsilateral interdigital space samples. (http://www.ncbi.nlm.nih.gov/pubmed/8922818)

Question 12

A 29-year-old man comes to the office due to 2 weeks of malaise and body aches.  Initially he attributed these symptoms to a viral infection, but yesterday he noticed a skin rash.  He has had no cough, chest pain, shortness of breath, nausea, vomiting, or diarrhea.  The patient has no significant past medical history.  He drinks alcohol socially, smokes marijuana occasionally, and does not use intravenous drugs.  He has been sexually active with 2 women over the past year.  The patient recently returned from a ski trip to Vermont.
Temperature is 37.8 C (100 F), blood pressure is 112/68 mm Hg, and pulse is 92/min.  A diffuse maculopapular rash is seen on the trunk and extremities, with patchy areas of hair loss on the scalp.  Sclerae are anicteric.  No oral lesions are present.  Rubbery palpable lymph nodes are present in the anterior and posterior cervical areas.  No murmurs are heard and the lungs are clear on auscultation.  The abdomen is soft and nontender and the spleen is not palpable.  The penis is uncircumcised with no lesions, ulcerations, or discharge.
Laboratory results are as follows:
 Which of the following is the most likely diagnosis?

Accepted Answer

This patient has a diffuse maculopapular rash on the trunk and extremities, patchy hair loss, cervical lymphadenopathy, and mild hepatitis. In a sexually active patient, this presentation is highly suggestive of secondary syphilis. Approximately 25% of patients with untreated primary syphilis progress to secondary syphilis within weeks or a few months. Often these patients did not notice the chancre of primary syphilis and have no history of a genital lesion. Secondary syphilis is associated with the following manifestations: Systemic symptoms (eg, fever, malaise, headache, anorexia, diffuse lymphadenopathy)Maculopapular rash involving the entire trunk and extremities (including palms and soles)Condyloma latum (painless wartlike lesions)Generalized lymphadenopathy (enlarged epitrochlear nodes are characteristic)"Moth-eaten" alopeciaDiffuse organ involvement (eg, mild hepatitis, uveitis, meningitis) Systemic symptoms (eg, fever, malaise, headache, anorexia, diffuse lymphadenopathy) Maculopapular rash involving the entire trunk and extremities (including palms and soles) Maculopapular rash Condyloma latum (painless wartlike lesions) Generalized lymphadenopathy (enlarged epitrochlear nodes are characteristic) "Moth-eaten" alopecia "Moth-eaten" alopecia Diffuse organ involvement (eg, mild hepatitis, uveitis, meningitis) The liver manifestations of secondary syphilis generally include a high serum alkaline phosphatase with normal or mildly elevated transaminases. Serologic testing in secondary syphilis is nearly always positive. Diagnosis is established by a positive VDRL or rapid plasma reagin test and confirmed by a treponemal-specific test (eg, FTA-ABS). Treatment consists of a single dose of intramuscular, long-acting penicillin. (Choice A) Erythema multiforme is a target-shaped lesion that is associated with herpes simplex virus infection. Lesions most commonly occur on the extensor surfaces of the extremities (particularly the hands and feet). Erythema multiforme (Choice B) Chronic hepatitis B virus can be associated with extrahepatic manifestations (eg, polyarteritis nodosa, membranous nephropathy) in 10-20% of cases. Although palpable purpura can occur, maculopapular rash is rare. (Choice C) Infectious mononucleosis can cause malaise, myalgia, and generalized rash (eg, maculopapular, urticarial, petechial). However, rash is most common after the administration of amoxicillin. In addition, patients usually also have fever, pharyngitis, lymphadenopathy, and atypical lymphocytosis. Alopecia would be atypical. (Choice D) Rocky Mountain spotted fever is a tick-borne illness that usually presents with systemic symptoms followed several days later by a macular, petechial rash. This disease does not generally cause alopecia or significant lymphadenopathy. Educational objective: Secondary syphilis can produce a wide variety of manifestations including diffuse maculopapular rash (most characteristic), systemic symptoms (eg, fever, malaise, headache, anorexia, diffuse lymphadenopathy), and diffuse organ involvement (eg, mild hepatitis, uveitis). Diagnosis is confirmed with serologic testing using nontreponemal (eg, rapid plasma reagin, VDRL) and treponemal (eg, FTA-ABS) assays. __________ References: Syphilis: a reemerging infection. (http://www.ncbi.nlm.nih.gov/pubmed/22963062) The rash of secondary syphilis. (http://www.ncbi.nlm.nih.gov/pubmed/17200385)

Question 13

A 36-year-old woman comes to the physician complaining of recurrent vesicular lesions on her lips.  The lesions always occur at the lip borders.  Her pharynx and oral mucosa are not involved.  The appearance of the lesions is preceded by tingling, burning, and discomfort in the area as well as mild malaise.  She has approximately 1 to 2 episodes a year.  The patient relates that these lesions are uncomfortable and result in an unprofessional appearance at work.  She has no genital lesions and is in otherwise good health.  There is no history of tobacco, alcohol, or illicit drug use.  She is monogamous with her husband.
Physical examination is unremarkable.
Which of the following is the best next step in management of this patient?

Accepted Answer

This patient most likely has secondary herpes simplex type 1 (HSV-1), commonly referred to as herpes simplex labialis. The virus reactivates within the trigeminal sensory ganglion, resulting in recurrent painful vesicles that appear at the vermillion border of the lips. Secondary infection may present with prodromal symptoms (eg, pain, burning, tingling, or pruritus) near the reactivation site lasting about 5 days from onset to resolution of the lesion. In contrast, primary HSV-1 seen in children and young adults can cause significant pharyngitis and intraoral lesions. The treatment of HSV-1 infection depends on whether the infection is primary (which tends to be more severe and symptomatic) or secondary, the extent and severity of symptoms, and the frequency of recurrences. Treatment options for recurrent HSV-1 infections include symptomatic, episodic, or chronic suppressive treatment. Recurrent HSV-1 with minimal clinical symptoms can be treated with symptomatic therapy (eg, anesthetics or antiseptics) without the need for antiviral therapy. Recurrent HSV-1 with pain or discomfort usually requires oral antiviral therapy at prodromal symptom onset, as in this patient (Choice D). These agents prevent viral replication and are therefore most effective when administered early in the course. Treatment speeds up healing of lesions and shortens symptom duration and severity. (Choice A) Chronic suppressive therapy (daily acyclovir or valacyclovir) is recommended for patients with > 4 episodes a year, painful or disfiguring lesions without a prodrome, or HSV recurrences accompanied by complications such as recurrent aseptic meningitis. (Choice B) This patient does not have a history of genital ulcers and is in a monogamous relationship. Recurrent herpes simplex labialis is common in the immunocompetent general population and per se does not warrant testing for sexually transmitted diseases. (Choice E) Topical antiviral therapy (eg, acyclovir) may also improve recurrent lesions. However, it is not preferred over oral therapy due to modest clinical improvement and the need for frequent applications (5 times a day). Educational objective: Patients with symptomatic recurrent herpes labialis should be treated with oral antiviral therapy (acyclovir, famciclovir, or valacyclovir) at symptom onset (eg, pain, burning, tingling, or pruritus). Chronic suppressive therapy (daily acyclovir or valacyclovir) is recommended for patients with > 4 episodes a year, painful or disfiguring lesions without a prodrome, or herpes simplex virus recurrences with complications (eg, aseptic meningitis). __________ References: Treatment of common cutaneous herpes simplex virus infections. (http://www.ncbi.nlm.nih.gov/pubmed/10750877) Treatment and prevention of herpes labialis. (http://www.ncbi.nlm.nih.gov/pubmed/19074705) Nongenital herpes simplex virus. (http://www.ncbi.nlm.nih.gov/pubmed/21121552)

Question 14

A 32-year-old nurse is evaluated 3 days after being exposed to a patient with active pulmonary tuberculosis.  The source patient presented with cough, and a chest radiograph revealed a cavitary lung lesion.  His sputum testing returned positive for acid-fast bacilli.  The nurse cared for the patient for several hours without using respiratory precautions before airborne isolation precautions were implemented.  She has had no symptoms and has no prior medical problems.  Her only medication is an oral contraceptive.  Vital signs are within normal limits, and physical examination shows no abnormalities.
Tuberculin skin test (TST) is administered and reveals a 2-mm induration at 48 hours.
Which of the following is the most appropriate next step in management of the nurse?

Accepted Answer

11ec193a_985c_35a4_853d_81fa2a3994dd_MD0002_00 Patients with pulmonary tuberculosis (TB) who have acid-fast bacilli in sputum smear and/or cavitary lung lesions are highly infectious. Therefore, close contacts require investigation and monitoring for potential exposure. A tuberculin skin test (TST) should be performed within a week; TST induration ≥5 mm is considered positive in this setting. However, the window period from infection to detectable skin test reactivity is generally 2-12 weeks. As a result, the Centers for Disease Control and Prevention recommends repeat TST testing 8-12 weeks after exposure for those with negative initial TST. Patients whose repeat TST is negative are cleared. Those with positive TST require further evaluation for active TB with symptom review and chest x-ray. A similar approach would apply for interferon gamma release assays, which appear to have a window period of 4-6 weeks (Choice B). (Choice E) Patients with latent TB are often treated with 9 months of daily isoniazid. This patient should not be treated unless TST is positive and no symptoms or signs of active pulmonary TB are present. Educational objective: For close contacts of a patient with tuberculosis, a tuberculin skin test (TST) reaction of ≥5 mm induration is considered positive and warrants further evaluation (chest x-ray, symptom review). However, the TST can take up to 8-12 weeks to become positive. Therefore, individuals in close contact with an infected person who have a negative initial TST should have the test repeated 8-12 weeks after exposure. __________

Question 15

A 24-year-old woman comes to the physician with joint pain and malaise for the past 2 weeks.  She had pain in her right wrist and elbow initially, but now it involves primarily the right knee.  Yesterday, she noted a red bump on her finger.  She lives in Connecticut.  The patient has no medical problems and takes no medications.  She does not use tobacco, alcohol, or illicit drugs.  She lives alone and has had a boyfriend for the past 2 years.  Her last menstrual period was 2 weeks ago.  Her mother suffers from hypertension and arthritis.
The patient's temperature is 38.1° C (100.6° F), blood pressure is 105/85 mm Hg, and pulse is 99/min.  Physical examination shows no neck masses or lymphadenopathy.  There are no cardiac murmurs.  The spleen is not enlarged.  The right knee is warm and slightly swollen without erythema.  Range of motion is unrestricted.  There is a pustule on the right index finger but otherwise there are no skin rashes.
Which of the following is the best next step in management of this patient?

Accepted Answer

11ec193a_985d_bc46_853d_4315264638bc_MD0002_00 This patient's presentation of fever, arthralgias, and pustular skin lesion suggests disseminated gonococcal infection (DGI). Suspected DGI may present as purulent arthritis without skin lesions or a triad of migratory asymmetric polyarthralgias, tenosynovitis, and painless pustular skin lesions with fever. Most patients do not recall recent genitourinary infection, and women are more commonly affected. Purulent arthritis usually affects knees, ankles, and wrist joints. Diagnosis requires drainage of purulent arthritis with synovial fluid analysis. Synovial fluid may show up to 50,000 cells/mm³, but many patients have < 10,000 cells/mm³. Blood cultures (2 sets) are more likely to be positive in patients with the classic triad but can be negative. As a result, isolation of the Gram-negative diplococcus from mucosal sites (eg, pharyngeal, rectal, urethral, or cervical swabs) is preferred for diagnosis and is positive in up to 50% of patients. Treatment involves parenteral ceftriaxone, which can be switched to oral cefixime when symptoms improve. Total duration of therapy is usually 7-14 days (longer for septic arthritis). Concomitant treatment for chlamydia with azithromycin or doxycycline is also recommended, as is treatment of sexual partners. In addition, all patients should be tested for HIV and syphilis. Patients with recurrent DGI should be evaluated for terminal complement deficiencies. (Choices B & C) Doxycycline is recommended empirically in patients with suspected Lyme disease. Lyme disease rash has characteristic central clearing (erythema migrans). Arthritis is also a late manifestation of Lyme disease, and antibodies to Borrelia burgdorferi are negative in early localized disease. (Choice D) Parvovirus can cause peripheral edema, symmetric small joint arthritis, and aplastic anemia. It is most commonly seen in patients with sickle cell disease and those exposed to multiple children (eg, day care workers). However, it does not typically cause a pustular rash. (Choice E) Rheumatoid arthritis is associated with subcutaneous nodules instead of the pustular lesions seen in this patient. Educational objective: Asymmetric migratory joint pain and pustular lesions are characteristic of disseminated gonococcal infection. Diagnosis involves blood cultures, synovial fluid analysis (if purulent arthritis is present), and mucosal (eg, pharyngeal, rectal, urethral, or cervical) cultures. Treatment is ceftriaxone for 7-14 days and concomitant treatment of chlamydia with azithromycin or doxycycline. __________ References: Gonococcal arthritis (disseminated gonococcal infection). (http://www.ncbi.nlm.nih.gov/pubmed/16297736)

Question 16

A 36-year-old man who just returned from a vacation in the Caribbean complains of an intensely pruritic skin rash.  He spent a lot of time outdoors on the beach and applied sunscreen daily.  He initially thought the rash was an allergic reaction, but it began expanding.  The affected area is shown in the photograph.

Which of the following is the most likely diagnosis?
A)Cutaneous leishmaniasis
B)Larva migrans
C)Mycetoma
D)Swimmer's itch

Accepted Answer

The answer of A 36-year-old man who just returned from...

Question 17

A 35-year-old woman who was recently diagnosed with HIV comes to the office for evaluation after moving to New York City from Tucson, Arizona. She began taking highly active antiretroviral therapy 9 months ago and has been compliant with the regimen. She also takes trimethoprim/sulfamethoxazole for Pneumocystis pneumonia prophylaxis. The patient reports no symptoms except for occasional nausea. Her CD4 count 3 months ago was 210/mm³. She also has a history of asthma, which is stable with inhaled beclomethasone therapy. Vital signs are within normal limits. Examination shows no abnormalities. Laboratory results are as follows: The patient's viral load is undetectable. Chest x-ray shows no acute disease. Which of the following is the best next step in management of this patient?

Accepted Answer

11ec193a_9860_545a_853d_7fb123f0a03c_MD0002_00 Pneumocystis jiroveci pneumonia (PCP) is a common AIDS-defining illness and is a major cause of death in patients with untreated AIDS. Prior to the use of antiretroviral therapy (ART), 70%-80% of patients with AIDS developed PCP, and approximately one-third of these individuals died from the condition. The vast majority of cases occur in patients with CD4 counts <200/mm³. ³ Chemoprophylaxis against PCP is recommended for all patients with HIV who have CD4 counts <200/mm³. Chemoprophylaxis should also be considered in those with higher CD4 counts who develop oropharyngeal candidiasis (indicating susceptibility to opportunistic infections) or have low CD4 count percentage (<14%). Once-daily, double-strength, oral trimethoprim-sulfamethoxazole (TMP-SMX) is the preferred agent. Alternate medications include dapsone, pentamidine, and clindamycin/primaquine. Prophylaxis can be discontinued when ART improves CD4 counts to >200/mm³ for >3 months, as in this patient. Cessation reduces the risk of drug toxicity/interactions and of developing drug- resistant organisms. (Choice A) Azithromycin prophylaxis against Mycobacterium avium complex was previously recommended for patients with AIDS who have CD4 counts <50/mm³ but is no longer recommended given the low risk of MAC among patients taking ART and the lack of differences in MAC disease outcomes between those who did or did not receive MAC prophylaxis. ³ (Choice B) Primary chemoprophylaxis against coccidiomycosis is not recommended for HIV-positive patients. However, patients who live in or travel to endemic regions can be screened for exposure with twice-annual serologic testing. Those who become seropositive and have CD4 counts <250/mm³ are generally given fluconazole prophylaxis if no disease manifestations are present. ³ (Choice D) Beclomethasone has stabilized this patient's asthma, and stopping the drug would likely worsen her condition. This drug has minimal interactions with ART and TMP-SMX. Educational objective: Prophylaxis for Pneumocystis pneumonia is recommended for patients with AIDS who have CD4 counts <200/mm³. Prophylaxis can be safely discontinued in patients on antiretroviral therapy who have CD4 counts >200/mm³ for >3 months. ³ ³ __________ References: Long-term safety of discontinuation of secondary prophylaxis against Pneumocystis pneumonia: prospective multicentre study. (http://www.ncbi.nlm.nih.gov/pubmed/15577626) Pneumocystis jirovecii prophylaxis discontinuation based upon total lymphocyte count in HIV-infected adults treated with antiretroviral therapy. (http://www.ncbi.nlm.nih.gov/pubmed/20606220)

Question 18

A 27-year-old woman comes to the physician for ear pain and decreased hearing.  Eight days ago, she developed rhinorrhea and a mild sore throat.  Three days later, she had decreased hearing and pain in her right ear.  The patient went to an urgent care clinic and was prescribed amoxicillin, which she has taken since.  Despite the amoxicillin, she continues to have ear pain and diminished hearing.  She has no ear drainage, fever, chills, or headache.  She is in good health and her only medication is birth control pills.
Vital signs are normal.  There is no nystagmus.  Otoscopic examination shows a cloudy, red, bulging tympanic membrane.  Hearing is diminished in her right ear.  A tuning fork placed in the center of her head lateralizes to the right.  There is no posterior ear pain.  There is no pharyngeal abnormality on examination.  Her neck is supple, and gait and balance appear normal.  All cranial nerves are intact.
Which of the following is the best management for this patient?

Accepted Answer

This patient has acute otitis media. An allergic rhinitis or upper respiratory illness commonly precedes the onset of otitis media. Eustachian tube dysfunction or occlusion from inflammation is the primary factor in the pathogenesis. Blockage of the Eustachian tube causes fluid accumulation in middle ear, with subsequent bacterial growth. The 3 most common organisms are Streptococcus pneumoniae, followed by nontypeable Hemophilus influenzae and Moraxella catarrhalis. Patients usually complain of severe ear pain and hearing loss. Fever may not be present. An otoscopic examination may show redness, opacification, air-fluid level, and bulging of the tympanic membrane. Use of a pneumatic otoscope would reveal poor movability of the tympanic membrane when pneumatic pressure is applied. A tuning fork examination can add to the diagnosis by revealing conductive hearing loss. In an immunocompetent host with no previous history of otitis media, amoxicillin is considered first-line treatment. If symptoms do not improve within 48-72 hours, the patient should be re-examined for a possible new area of infection or inadequate therapy. In cases of antibiotic failure, amoxicillin-clavulanate is the next best therapy to cover beta-lactamase-producing H influenzae. For patients allergic to penicillin, alternatives to amoxicillin therapy are second-generation (eg, cefuroxime) or third-generation (eg, cefdinir) cephalosporins. In patients allergic to beta-lactam antibiotics, a macrolide (eg, azithromycin) can be used. (Choice C) A CT scan is usually done in patients who do not respond and/or develop complications despite being on an adequate antibiotic regimen. Common complications include mastoiditis, brain abscess, and lateral sinus thrombosis (need an MRI). This patient has no posterior ear pain, fever, or headache that would suggest extension of an infection. (Choice D) Myringotomy is used to aid middle ear drainage for individuals with unresolved chronic otitis media with effusion or mastoiditis. Neither is present in this patient. (Choice E) Nasopharyngoscopy can be considered in patients with recurrent otitis media (> 2 episodes in a 6-month period) to evaluate for other possible causes of Eustachian tube or nasopharyngeal obstruction (eg, malignancy). Educational objective: Adult otitis media is a clinical diagnosis based on the history of ear pain and conductive hearing loss as well as otoscopic findings of erythema, opacification, bulging, or air-fluid level of the tympanic membrane. Although amoxicillin is first-line antibiotic therapy, amoxicillin-clavulanate is a better choice if otitis media is unresolved in 48-72 hours. __________ References: Purulent otitis media in adults. (http://www.ncbi.nlm.nih.gov/pubmed/1444690) Acute complications of otitis media in adults. (http://www.ncbi.nlm.nih.gov/pubmed/16402975)

Question 19

A 63-year-old man with a history of hypertension, type 2 diabetes, and severe osteoarthritis underwent a right total knee arthroplasty 3 months earlier.  He comes to his primary care physician with persistent pain and swelling of the right knee.  The patient has pain with activity and at rest, with the most significant pain associated with weight bearing.  He has no fevers, chills, nausea, vomiting, or diarrhea.  He goes to rehabilitation but his participation has been limited over the past week due to persistent pain.
His temperature is 37.1 C (98.7 F), blood pressure is 114/74 mm Hg, pulse is 86/min, and respirations are 18/min.  Examination shows a moderately swollen right knee with decreased range of motion.  The surgical scar is intact without surrounding erythema.  Examination of the left knee is within normal limits.
An x-ray of the knee reveals an intact prosthesis.  Laboratory tests, including complete blood count, electrolyte panel, C-reactive protein, and erythrocyte sedimentation rate, have been ordered.
Which of the following is the best next step in management of this patient's condition?

Accepted Answer

This patient's increased knee pain and swelling 3 months after arthroplasty is concerning for either aseptic mechanical complication of the prosthesis or early-onset prosthetic joint infection (PJI). Mechanical complications typically present with pain associated with weight bearing or activity. PJI often presents with persistent pain and other localized or systemic symptoms of infection (eg, joint effusion, wound drainage, fever, erythema, induration, edema). PJI can present as early (< 3 months), delayed (3-12 months), or late onset (> 12 months) after surgery. Although plain films can be helpful in establishing the diagnosis of PJI, the sensitivity and specificity of x-ray findings are limited. The absence of x-ray findings should not deter further consideration of PJI in the appropriate setting. Diagnostic arthrocentesis should be performed in patients with suspected PJI unless open surgical drainage is anticipated or an obvious sign of infection, such as a sinus tract, is present. Synovial fluid analysis should include a cell count and differential and Gram stain and culture for aerobic and anaerobic organisms. Erythrocyte sedimentation rate and C-reactive protein can be useful adjunctive tests in establishing the diagnosis. Blood cultures should also be performed. Early-onset PJI usually improves with surgical debridement followed by prolonged antibiotics. Delayed and late onset may also require prosthesis removal if debridement shows an infected prosthesis. (Choice B) Unless there are clear signs of sepsis, the use of antibiotics should follow arthrocentesis to maximize the yield of synovial fluid culture and direct antibiotic therapy. This patient appears clinically stable and should first undergo arthrocentesis. (Choice C) MRI can be done only in patients with titanium or tantalum prostheses but is still not as sensitive as arthrocentesis. (Choice D) Naproxen with close follow-up is indicated for symptomatic relief in noninfectious causes of joint pain (eg, bursitis). Although naproxen may also help this patient's symptoms, he should first undergo arthrocentesis to evaluate for PJI. (Choice E) Technetium 99m colloid bone scan is nonspecific and may show high false-positive results in the early months after prosthetic joint implantation due to periprosthetic bone remodeling. Educational objective: Prosthetic joint infection should be considered in patients with increasing pain after joint replacement. Arthrocentesis establishes the diagnosis. Treatment involves surgical debridement (or removal in delayed or late-onset cases) followed by a prolonged course of intravenous antibiotics. __________ References: Diagnosis and management of prosthetic joint infection: clinical practice guidelines by the Infectious Diseases Society of America. (http://www.ncbi.nlm.nih.gov/pubmed/23223583) Prosthetic joint infection: diagnosis and management. (http://www.ncbi.nlm.nih.gov/pubmed/21905787)

Question 20

A 37-year-old man comes to the physician for acute onset of a sore throat that has gotten progressively worse during the day.  He is also experiencing some mild myalgias.  For the past 2 days, he has had subjective fevers and a nonproductive cough.  He does not have chills or fatigue.  The patient has not been exposed to a similar illness and has no HIV risk factors.  He has no significant past medical history, takes no medications, and has no known allergies.
His temperature is 37.2 C (99 F), blood pressure is 130/80 mm Hg, pulse is 72/min, and respirations are 16/min.  Oropharyngeal examination shows slightly enlarged tonsils with grayish-white exudates.  There are a few palpable, bilateral, small, and slightly tender anterior cervical nodes.  Auscultation of the heart and lungs is normal.  The abdomen is soft, and there is no hepatosplenomegaly.
What is the best next step in management of this patient?

Accepted Answer

11ec193a_985a_af02_853d_a3b1c3eca2c1_MD0002_00 This patient has acute pharyngitis and fulfills 3 of 4 Centor criteria (he does not fulfill the criterion of "absence of cough" given that he has a nonproductive cough). The most appropriate next step is to obtain a rapid antigen test to exclude group A streptococcal (GAS) pharyngitis as untreated patients are at risk for developing complications (eg, rheumatic fever, acute glomerulonephritis, peritonsillar abscess). The Centor criteria (tonsillar exudates, tender anterior cervical lymphadenopathy, fever by history, and absence of cough) help determine the likelihood of GAS pharyngitis and guide further workup and treatment. Patients with 0-1 criteria do not require further work up or treatment (high negative predictive value). Patients with >2 criteria should be evaluated with a rapid streptococcal antigen test (RSAT), which has high specificity. Some clinicians will treat GAS pharyngitis empirically if all 4 criteria are met. Guidelines may use different cutoffs, but the presence of 3 criteria (as in this patient) generally warrants testing. (Choice A) Antibiotics are indicated in patients with a positive RSAT or those who fulfill 4 Centor criteria. Oral penicillin V and amoxicillin are common first-line agents due to their modest cost, narrow spectrum, and tolerability. First-generation cephalosporins (eg, cephalexin) are an alternate therapy if treatment fails. Macrolides (eg, erythromycin) are used for penicillin-allergic patients. (Choice B) Nonsteroidal anti-inflammatory drugs are appropriate for symptomatic relief of pain associated with nonspecific pharyngitis, but this patient should first be evaluated with an RSAT. (Choice C) Infectious mononucleosis (IM) can present in a similar fashion, but it is more common in patients age 15-24. Other signs and symptoms that are commonly seen with IM but are absent in this patient include fatigue (90%-100%), posterior lymphadenopathy (100%), and splenomegaly (60%). (Choice E) Although throat culture has high sensitivity and specificity in identifying GAS infection, the delay in obtaining results often limits its use in the acute setting. Throat culture can be considered in patients who have a negative RSAT result yet in whom the suspicion for GAS infection is still high (eg, 4 positive Centor criteria with negative RSAT). Educational objective: The Centor criteria (tonsillar exudates, tender anterior cervical lymphadenopathy, fever by history, and absence of cough) are widely used to determine the likelihood of group A streptococcal pharyngitis. Patients with >2 criteria should have a rapid streptococcal antigen test and receive therapy with oral penicillin or amoxicillin if test results are positive. __________ References: Principles of appropriate antibiotic use for acute pharyngitis in adults: background. (http://www.ncbi.nlm.nih.gov/pubmed/11255530) Executive Summary: 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/23091044)

Exam 3: Office/Health Center