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?

Question

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?

Quizplus · 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)

A 10-Year-Old Boy Is Brought to the Emergency Department Due