Snapshot A 10-year-old girl presents with a fever and migrating joint pains in the knees and elbows. She reports having had a sore throat a few days ago. On physical exam, she is febrile and has barely raised erythematous serpentine-like lesions on her back. A rapid streptococcal test is positive and there is an elevated erythrocyte sedimentation rate. She is given antibiotics for this disease. Introduction Clinical definition acute inflammation of multiple systems caused by an immunologic reaction to group A streptococcus infection Epidemiology Demographics children and adolescents most common in developing nations Location mitral valve > aortic valve > tricuspid valve most commonly affects the high-pressure valves Risk factors poverty and overcrowding preceding group A streptococcal pharyngitis Etiology Typically due to inadequate treatment of group A streptococcal infection Pathogenesis abnormal immune response to group A streptococci molecular mimicry between streptococcal M protein and self-proteins including cardiac proteins, keratin, laminin, and vimentin immune-mediated (type II) hypersensitivity disease is characterized by carditis arthritis Sydenham chorea caused by antibodies that cross the blood-brain barrier and bind dopamine D1 and D2 receptors erythema marginatum subcutaneous nodules Associated conditions Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infection (PANDAS) believed to be an autoimmune condition caused by antibodies targeting the basal ganglia after group A streptococcal infection resulting in acute onset of obsessive compulsive disorder and/or tics Presentation Symptoms migratory joint pains, especially in the knees, ankles, and elbows chest discomfort heart failures (rare) Physical exam fever may have dyspnea new murmur on cardiac exam may indicate carditis firm and painless subcutaneous nodules over bony prominences often occurs with carditis erythema marginatum evanescent flat or barely raised ring-like or serpentine lesion on trunk Sydenham chorea involuntary, jerky, purposeless movements of the hands, feet, face, or tongue Imaging Echocardiography indications when murmur is auscultated on examination suspicious for rheumatic heart disease to confirm complication of acute rheumatic fever findings valvular abnormalities, including regurgitations or stenosis Studies Positive throat culture or rapid antigen test for Streptococcus Labs ↑ anti-streptolysin O (ASO) titers ↑ anti-deoxyribonuclease B titers Electrocardiography prolonged PR interval first-degree heart block Histology Aschoff bodies granuloma with giant cells on heart valves Anitschkow cells enlarged macrophages within Aschoff bodies Differential Infective endocarditis distinguishing factors no association with group A streptococcal infection other findings including Roth spots, Osler nodes, Janeway lesions, and splinter hemorrhages on nail bed vegetations seen on valves on imaging DIAGNOSIS Making the diagnosis based on clinical presentation, clinical or laboratory evidence of preceding group A streptococcal infection, and confirmation with 2 major Jones criteria or 1 major and 1 minor Jones Criteria Major Criteria Minor Criteria Joints (migratory arthritis) O looks like the heart (carditis) Nodules (subcutaneous) Erythema marginatum Sydenham chorea Fever Antecedent strep infection Arthralgias ↑ Erythrocyte sedimentation rate ↑ C-reactive protein First-degree heart block Treatment Management approach patients must be treated adequately with antibiotics to prevent rheumatic heart disease patients must then be put on long-term prophylaxis to prevent recurrence Medical penicillins indication for all patients macrolides indications for patients allergic to penicillin nonsteroidal anti-inflammatory drugs (NSAIDs) indication for patients with joint pain or fever Complications Rheumatic heart disease Prognosis Occurs 2-3 weeks after pharyngitis, except carditis and chorea carditis occurs after months chorea presents after months Risk of recurrence decreases with time