A 9-year-old girl is brought to the emergency department due to sudden onset of uncontrollable, continuous writhing of the arms and hands and grimacing of the face. A month ago, she had a sore throat and fever that resolved after a few days without treatment. The girl and her family recently returned to the United States after living in Honduras for a year. The patient takes no daily medications and her vaccinations are current. Vital signs are normal. On examination, the patient has multiple dental caries, and the oropharynx is nonerythematous and without exudate or tonsillar enlargement. Cardiac examination reveals a pericardial friction rub. Laboratory studies show an erythrocyte sedimentation rate of 65 mm/h. ECG shows a prolonged PR interval and diffuse ST elevations. Infection with which of the following organisms is the most likely cause of this patient's symptoms?

Question

A 9-year-old girl is brought to the emergency department due to sudden onset of uncontrollable, continuous writhing of the arms and hands and grimacing of the face.  A month ago, she had a sore throat and fever that resolved after a few days without treatment.  The girl and her family recently returned to the United States after living in Honduras for a year.  The patient takes no daily medications and her vaccinations are current.  Vital signs are normal.  On examination, the patient has multiple dental caries, and the oropharynx is nonerythematous and without exudate or tonsillar enlargement.  Cardiac examination reveals a pericardial friction rub.  Laboratory studies show an erythrocyte sedimentation rate of 65 mm/h.  ECG shows a prolonged PR interval and diffuse ST elevations.  Infection with which of the following organisms is the most likely cause of this patient's symptoms?

Quizplus · Accepted Answer

11ec25c8_d6cd_c91d_bc81_41549ddaa877_MD0003_00 This patient most likely has acute rheumatic fever (ARF), an immune-mediated consequence of untreated streptococcal pharyngitis (bacterial throat inflammation and fever). ARF can present with carditis (friction rub, prolonged PR interval, diffuse ST elevations), chorea (continuous, rapid, irregular jerks), and elevated erythrocyte sedimentation rate. Other major criteria for ARF include erythema marginatum, subcutaneous nodules, and migratory arthritis. Sydenham chorea has the longest latency period of any symptom and can occur anywhere from 1 to 8 months after the episode of pharyngitis. Diagnosis is made if the patient has 2 major Jones criteria, 1 major and 2 minor criteria, or if either Sydenham chorea or carditis is present. erythema marginatum Pharyngitis due to Streptococcus pyogenes (group A Streptococcus) is often self-resolving, as seen in this patient. However, a 10-day course of oral penicillin is recommended to prevent ARF. In addition, ARF can recur with increasing severity after successive group A streptococcal infections. Therefore, patients with ARF should receive prophylactic long-acting, intramuscular benzathine penicillin G for several years. This treatment is meant to eradicate bacterial carriage to prevent recurrent ARF and worsening rheumatic heart disease. (Choice A) Coxsackievirus is the most common pathogen responsible for pericarditis and myocarditis. It also causes vesicular pharyngitis (herpangina) in young children. However, it would not cause the chorea seen in this patient. (Choice B) Cytomegalovirus typically presents with a mononucleosis-like syndrome, including fever, pharyngitis, and lymphadenopathy. Although pericarditis and myocarditis can occur, chorea is not associated. (Choice C) Parvovirus B19 infection classically causes erythema infectiosum ("slapped cheek" rash) in children but can also cause arthralgias, arthritis, and myocarditis. It is not associated with ARF. (Choice D) Streptococcus mutans is a member of the viridans group of streptococci and is a common cause of dental caries and endocarditis. Chorea is not seen with these infections. (Choice F) Trypanosoma cruzi is the organism responsible for Chagas disease, which is associated with cardiomyopathy (due to myopericarditis) and achalasia. ARF is not associated with this organism. Educational objective: Acute rheumatic fever is a complication of untreated Streptococcus pyogenes pharyngitis. Major clinical features include carditis, chorea, erythema marginatum, subcutaneous nodules, and migratory arthritis. References: Sydenham's chorea as presentation of rheumatic heart disease. (http://www.ncbi.nlm.nih.gov/pubmed/27180377) Sydenham's chorea: not gone but perhaps forgotten. (http://www.ncbi.nlm.nih.gov/pubmed/26374756)

A 9-Year-Old Girl Is Brought to the Emergency Department Due