Rheumatic Fever

Rheumatic Fever Diagnosis & Tests

Given the different manifestations of this disease, there is no specific test which can definitively establish a diagnosis. In addition to a careful physical examination of heart sounds, skin, and joints, blood samples may be taken as part of the evaluation. These include tests for recurrent strep infection (ASO or antiDNAse B), complete blood counts, and sedimentation rate (ESR). As part of the cardiac evaluation, an electrocardiogram may also be done.

In order to standardize the diagnosis of rheumatic fever, several minor and major criteria have been developed. These criteria, in conjunction with evidence of recent streptococcal infection, establish a diagnosis of rheumatic fever.

The major diagnostic criteria include:

• Carditis (heart inflammation)
• Polyarthritis
• Subcutaneous skin nodules
• Chorea (Sydenham's chorea)
• Erythema marginatum.

The minor criteria include fever, arthralgia (joint pain), elevated erythrocyte sedimentation rate, and other laboratory findings.

Two major criteria, or one major and two minor criteria, when there is also evidence of a previous strep infection (positive culture or rising antibody level -- ASO or antiDNAse B) support the diagnosis of rheumatic fever.