Rheumatic fever is an inflammatory disease that may develop after an infection with Streptococcus bacteria (such as strep throat or scarlet fever). The disease can affect the heart, joints, skin, and brain.

Rheumatic fever is common worldwide and is responsible for many cases of damaged heart valves. Although it has become far less common in the U.S. since the beginning of the 20th century, there have been a few outbreaks since the 1980s.

Rheumatic fever mainly affects children ages 6 -15, and occurs approximately 20 days after strep throat or scarlet fever. In up to a third of cases, the strep infection that caused rheumatic fever may not have had any symptoms.

About 3% of people with untreated strep infections get rheumatic fever. People who had a case of rheumatic fever are likely to develop flare-ups with repeated strep infections.

• Fever
• Joint pain, arthritis (mainly in the knees, elbows, ankles, and wrists)
• Joint swelling; redness or warmth
• Abdominal pain
• Skin rash (erythema marginatum)
  • Skin eruption on the trunk and upper part of the arms or legs
  • Eruptions that look ring-shaped or snake-like
• Skin nodules
• Sydenham's chorea (emotional instability, muscle weakness and quick, uncoordinated jerky movements that mainly affect the face, feet, and hands)
• Nosebleeds (Epistaxis)
• Heart (cardiac) problems, which may not have symptoms, or may result in shortness of breath and chest pain

Because this disease has different forms, there is no specific test that can firmly diagnose it. Your doctor will perform a careful exam, which includes checking your heart sounds, skin, and joints.

Your doctor may also do an electrocardiogram while testing your heart.

You may have blood samples taken to test for recurrent strep infection (such as anASO test), complete blood counts, and sedimentation rate (ESR).

Several major and minor criteria have been developed to help standardize rheumatic fever diagnosis. Meeting these criteria, as well as having evidence of a recent streptococcal infection, can help confirm that you have rheumatic fever.

The major diagnostic criteria include:

• Heart inflammation (carditis)
• Arthritis in several joints (polyarthritis)
• Nodules under the skin (subcutaneous skin nodules)
• Rapid, jerky movements (chorea, Sydenham's chorea)
• Skin rash (erythema marginatum)

The minor criteria include fever, joint pain, high ESR, and other laboratory findings.

You'll likely be diagnosed with rheumatic fever if you meet two major criteria, or one major and two minor criteria, and signs that you've had a previous strep infection.