Acute Rheumatic Fever

Definition

An autoimmune inflammatory illness after group A streptococcal infection, causing arthritis, carditis, chorea and rheumatic heart disease.

Aetiology

  • Molecular mimicry between streptococcal M protein and host tissue
  • Latent period of 1 to 5 weeks after pharyngitis
  • Streptococcal skin infection is also implicated in some populations

Epidemiology

  • Peak age 5 to 14 years
  • High incidence in low income settings and in Aboriginal, Torres Strait Islander, Māori and Pacific peoples

Classification

  • Revised Jones criteria (2015) require evidence of preceding group A streptococcal infection
  • Initial episode needs 2 major, or 1 major plus 2 minor criteria
  • Recurrence needs 2 major, 1 major plus 2 minor, or 3 minor criteria
  • Major criteria are carditis including subclinical echocardiographic findings, arthritis, chorea, erythema marginatum and subcutaneous nodules
  • Polyarthritis is the major joint criterion in low risk populations
  • Monoarthritis or polyarthralgia is also a major criterion in moderate and high risk populations
  • Minor criteria are fever, raised ESR or CRP, prolonged PR interval and arthralgia

Clinical Features

  • Migratory polyarthritis of large joints, mainly knees, ankles, elbows and wrists
  • Each joint is inflamed for days, with new joints involved as others settle
  • Pain is out of proportion to the signs
  • Rapid response to NSAIDs, which can mask the migratory pattern
  • Non-erosive, resolving without deformity
  • Sydenham chorea can appear months later as the only feature

Investigations

  • Raised ASOT or anti-DNase B titres
  • Throat culture is often negative by presentation
  • ECG for PR prolongation
  • Echocardiography for clinical or subclinical carditis
  • Joint aspiration in monoarthritis to exclude septic arthritis

Differential Diagnosis

Management

  • Benzathine benzylpenicillin. Eradicates streptococcus and continues every 3 to 4 weeks as secondary prophylaxis
  • NSAIDs. Naproxen or aspirin for arthritis and fever
  • Corticosteroids. Considered for severe carditis
  • Secondary prophylaxis. Continues for at least 10 years after the last episode

References

  1. Gewitz MH, Baltimore RS, Tani LY, Sable CA, Shulman ST, Carapetis J, Remenyi B, Taubert KA, Bolger AF, Beerman L, Mayosi BM, Beaton A, Pandian NG, Kaplan EL. Revision of the Jones Criteria for the diagnosis of acute rheumatic fever in the era of Doppler echocardiography. A scientific statement from the American Heart Association. Circulation. 2015, 131(20), 1806-18. PubMed
  2. Carapetis JR, Beaton A, Cunningham MW, Guilherme L, Karthikeyan G, Mayosi BM, Sable C, Steer A, Wilson N, Wyber R, Zühlke L. Acute rheumatic fever and rheumatic heart disease. Nat Rev Dis Primers. 2016, 2, 15084. PubMed

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 19 October 2026.