Rheumatic fever is an inflammatory disease that can develop when strep throat or scarlet fever isn't properly treated. Strep throat and scarlet fever are caused by an infection with streptococcus (strep-toe-KOK-us) bacteria.
Rheumatic fever most often affects children ages 5 to 15. But it can develop in younger children and adults. Although strep throat is common, rheumatic fever is rare in the United States and other developed countries.
Rheumatic fever can cause permanent damage to the heart, including damaged heart valves and heart failure. Treatment can ease pain, reduce damage from inflammation and prevent a recurrence of rheumatic fever.
Rheumatic fever symptoms result from inflammation in the heart, joints, skin or central nervous system. There may be few symptoms or several. Symptoms can change during the course of the disease. The onset of rheumatic fever usually occurs about 2 to 4 weeks after a strep throat infection.
Rheumatic fever signs and symptoms can include:
- Painful and tender joints — most often in the knees, ankles, elbows and wrists
- Pain in one joint that migrates to another joint
- Red, hot or swollen joints
- Chest pain
- Flat or slightly raised, painless rash with a ragged edge
- Heart murmur
- Jerky, uncontrollable body movements (Sydenham chorea) — most often in the hands, feet and face
- Outbursts of unusual behavior, such as crying or inappropriate laughing, that accompanies Sydenham chorea
- Small, painless bumps beneath the skin
When to see a doctor
Make an appointment with your child's health care provider if any of these signs or symptoms of strep throat occur:
- Sore throat that comes on suddenly
- Pain when swallowing
- Stomach pain, nausea and vomiting
Proper treatment of strep throat can prevent rheumatic fever.
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Rheumatic fever can occur after a throat infection from a bacteria called group A streptococcus. Group A streptococcus infections of the throat cause strep throat or, less commonly, scarlet fever.
Group A streptococcus infections of the skin or other parts of the body rarely trigger rheumatic fever.
The link between strep infection and rheumatic fever isn't clear. It appears that the bacteria trick the immune system into attacking otherwise healthy tissue.
The body's immune system typically targets infection-causing bacteria. In rheumatic fever, the immune system mistakenly attacks healthy tissue, particularly in the heart, joints, skin and central nervous system. This faulty immune system reaction results in swelling of the tissues (inflammation).
There's little chance of developing rheumatic fever when a strep throat infection is promptly treated with antibiotics and all the medication is taken as prescribed.
If a child has one or more episodes of strep throat or scarlet fever that aren't properly treated, rheumatic fever may occur.
Things that may increase the risk of rheumatic fever include:
- Genes. Some people have one or more genes that might make them more likely to develop rheumatic fever.
- Specific type of strep bacteria. Certain strains of strep bacteria are more likely to contribute to rheumatic fever than are other strains.
- Environmental factors. A greater risk of rheumatic fever is associated with overcrowding, poor sanitation and other conditions that can cause strep bacteria to easily spread among many people.
Inflammation caused by rheumatic fever can last a few weeks to several months. For some people, the inflammation causes long-term complications.
One complication of rheumatic fever is permanent damage to the heart (rheumatic heart disease). Rheumatic heart disease usually occurs years to decades after the original illness.
However, severe rheumatic fever can start to damage the heart valves while your child still has symptoms of the infection. Damage is most common with the valve between the two left chambers of the heart (mitral valve), but the other valves can be affected.
Rheumatic fever can cause the following types of heart damage:
- Narrowing of a heart valve (valve stenosis). This decreases blood flow.
- Leaky heart valve (valve regurgitation). Blood flows backward across the valve.
- Damage to heart muscle. The inflammation associated with rheumatic fever can weaken the heart muscle, affecting its ability to pump.
Damage to the heart valves or other heart tissues can lead to irregular, chaotic heartbeats (atrial fibrillation) or heart failure later in life.
The only way to prevent rheumatic fever is to treat strep throat infections or scarlet fever promptly and completely with a full course of appropriate antibiotics.