summary Acute Rheumatic Fever is a systemic reaction following Streptococcal pharyngitis which causes a characteristic rash and migratory arthritis that involves multiple large joints. Diagnosis is based on the Revised Jones criteria. Treatment is usually oral antibiotics and anti-inflammatories. Epidemiology Incidence 500k new cases per year worldwide Demographics children 5-15 years of age lower socioeconomic status developing countries Etiology Pathophysiology molecular biology autoimmune reaction within 1-4 weeks following Group A beta-hemolytic Streptococcus pyogenes pharyngitis molecular mimicry antibodies to M protein of GAS causing an inflammatory response to synovium, myocardium, and basal ganglia cells Presentation Symptoms rash joint pain and refusal to bear weight Physical exam arthritis red, swollen joints predominantly if the lower extremities, migratory rash erythema marginatum (pink rash on trunk and extremities that spares the face) other subcutaneous nodules on upper extremity extensor surfaces chorea carditis, first-degree heart block (prolonged PR interval) Imaging Radiographs may show effusion but often unremarkable Ultrasound/MRI equivocal cases where concern remains for septic arthritis Echocardiogram Lab Studies Serum labs antistreptolysin O titers elevated in 80% peripheral blood leukocytosis inflammatory markers ESR elevated CRP elevated Synovial Fluid Analysis Synovial Fluid Analysis Condition WBC (cells/mL) PMNs (%) Normal < 200 < 25% Effusion from trauma < 5,000 < 25% Toxic synovitis 5,000-15,000 < 25% Acute rheumatic fever 10,000-15,000 50% JRA 15,000-80,000 75% Septic arthritis > 50,000 > 75% Differential Lyme disease positive Lyme titers Septic arthritis purulent synovial fluid, elevated cell count Reiter/Reactive arthritis specific rheumatologic labs will be positive (HLA-B27) Juvenile Rheumatoid Arthritis specific rheumatologic labs will be positive (RF and ANA) Gout/Pseudogout synovial fluid positive for MSU or CPPD crystals Diagnosis Diagnosis based on Revised Jones criteria preceding Strep infection with 2 major criteria or 1 major and 2 minor criteria major criteria carditis polyarthralgia chorea erythema marginatum subcutaneous nodules minor criteria fever arthralgia prior rheumatic fever increased ESR prolonged PR interval (First degree heart block) prior Group A Strep infection Treatment Nonoperative oral antibiotics and anti-inflammatories indications acute infection confirmed by Modified Jones criteria arthralgias and/or fever modalities antibiotics Penicillin 250mg PO BID x10 days (or erythromycin if penicillin-allergic) Penicillin monthly x10 years to prevent rheumatic fever recurrence anti-inflammatories naprosyn more commonly used salicylates used historically but concern for liver derangement deters use Complications
All Videos (0) Podcasts (1) Basic Science⎪Acute Rheumatic Fever Basic Science - Acute Rheumatic Fever Listen Now 6:18 min 12/15/2020 49 plays 5.0 (1)