Rheumatic fever is an inflammatory disease that can develop as a serious complication of inadequately treated strep throat or scarlet fever. Strep throat and scarlet fever, which are is most common in 5-year-old to 15-year-old children, are caused by an infection with group A streptococcus bacteria.
Rheumatic fever can cause permanent damage to the heart, including damaged heart valves and heart failure. Treatments can reduce tissue damage from inflammation, lessen pain and other symptoms, and prevent the recurrence of rheumatic fever.
Rheumatic fever symptoms may vary. Namely, some people may have several symptoms, while others experience only a few. They usually last around four weeks, but can sometimes persist for several months. The onset of rheumatic fever usually occurs about two to four weeks after a strep throat infection and may include:
- Painful and tender joints (usually the ankles, knees, elbows or wrists);
- Swelling in the joints;
- Pain in one joint that migrates to another joint;
- Red, hot or swollen joints;
- Small, painless nodules beneath the skin;
- Chest pain;
- Heart murmur;
- Flat or slightly raised, painless rash with a ragged edge;
- Jerky, uncontrollable body movements (Sydenham chorea or St. Vitus' dance);
- Outbursts of unusual behavior.
Most experts believe rheumatic fever is caused by the immune system overreacting to the presence of group A streptococcus bacteria, and not by the bacteria itself. The immune system, which is the body’s defense against infection, mistakes healthy tissue for the streptococcus bacteria and causes parts of the body to become inflamed. Consequently, this triggers the symptoms of rheumatic fever, although it is unclear exactly why the immune system suddenly stops working properly.
Almost all cases develop a few weeks after a throat infection, during which, the lining of the throat becomes inflamed as the immune system responds to the infection. In cases of rheumatic fever, it seems that the process of inflammation spreads throughout your body in an uncontrolled way.
Factors that may increase the risk of rheumatic fever include:
- Family history;
- Type of strep bacteria;
- Environmental factors.
In some cases, the inflammation may cause long-term complications and it can cause permanent damage to the valves of the heart that is known as rheumatic heart disease, heart failure and stroke. The problems are most common with the valve between the two left chambers of the heart, but the other valves may be affected. The damage may result in one of the following conditions:
- Valve stenosis (narrowing of the valve, which results in decreased blood flow);
- Valve regurgitation (a leak in the valve, which allows blood to flow in the wrong direction);
- Damage to heart muscle.
Damage to the mitral valve, other heart valves or other heart tissues can cause problems with the heart later in life. Resulting conditions may include irregular and chaotic beating of the upper chambers of the heart or even heart failure.
The only known way to prevent rheumatic fever is to treat strep throat infections or scarlet fever promptly with a full course of appropriate antibiotics. The prevention requires the recognition and diagnosis of group A strep throat infections and the treatment with an appropriate antibiotic therapy.