Acute rheumatic fever and RHD - KFP-style written assessment

KFP 1 (10 marks)

A 9-year-old Aboriginal boy in a remote Top End community presents with 3 days of knee and ankle pain, fever 38.4°C, and a new apical systolic murmur. Two weeks ago he had a sore throat. You suspect acute rheumatic fever. ^[2]

1. What features of this presentation meet Jones major criteria? (3) ^[2]
2. What investigations confirm the diagnosis? (4) ^{[2] [20]}
3. What is the immediate management priority? (3) ^[3]

Model answers

1. Migratory polyarthritis involving large joints (knees, ankles) and carditis (new apical systolic murmur suggesting mitral regurgitation) are two major criteria. ^[2]
2. Confirm preceding GAS infection: ASO and anti-DNase B titres (rising on paired samples), throat swab. Inflammatory markers: ESR and CRP. Echocardiography is mandatory to assess carditis even when murmurs are absent. ECG for PR prolongation. ^{[2] [20]}
3. Hospital admission for full ARF workup and staging, echocardiography, notification to the RHD register, initiation of secondary prophylaxis planning, and treatment of the acute episode (NSAIDs for arthritis; antibiotics to eradicate GAS). ^{[3] [20]}