Rheumatic fever is an inflammatory disease that can happen after a person becomes infected with the Streptococcus bacteria.
Rheumatic fever was once a common cause of heart problems in childhood. It remains a serious childhood health problem in many developing countries. In North America, it's become much less common due to improved hygiene and routine use of antibiotics for infections. When it does strike, however, it can still have serious consequences for heart health.
Rheumatic fever is most frequent in children aged 5 to 15 years old, but can also affect adults and children younger than 5 years of age. However, there are no reliable figures on adults.
Rheumatic fever is caused by a combination of bacterial infection and immune system overreaction. It almost always follows a strep throat infection, which is an infection of the respiratory tract caused by bacteria of the Streptococcus family. Children are far more likely to get strep throat than adults.
Normally, Streptococcus causes a cough and a sore throat, and clears up with antibiotics. In some cases, however, children with strep throat begin complaining of pain in the joints or other unusual symptoms. This usually happens 2 to 4 weeks after the streptococcal infection (which may have already cleared up).
The disease has an affinity for the joints, the central nervous system (brain and spinal cord), and the heart. In the heart, the disease can affect the inner lining of the heart including the heart valves (endocarditis), the muscle of the heart (myocarditis), or the covering of the heart (pericarditis).
In some people, the body reacts with a massive immune system reaction to the affected areas. The cells that normally kill invading bacteria become so active that they also attack the affected tissues. The result in the joints is temporary arthritis (inflammation of the joints). In the heart, they can permanently damage heart valves, increasing the risk of heart problems later in life. Rheumatic fever can also cause problems with the nervous system that are usually reversible.
Symptoms and Complications
The symptoms of rheumatic fever depend on whether the heart, joints, or nervous system are affected. Most people with rheumatic fever have fever and joint pain. The joint pain (arthritis) usually affects large joints such as the knees, elbows, ankles, or wrists. The joint pain characteristically migrates from one joint to another, so that one or more joints may be swollen, red, and extremely tender. The joint pain is usually reversible.
Many people who develop rheumatic fever suffer damage to the tissues of the heart, which may include their heart valves (endocarditis), heart muscle (myocarditis), sac covering the heart (pericarditis), or all three. This may cause no symptoms, but some people feel heart palpitations or chest pain. Occasionally, there is heart failure, though few people in North America die during a rheumatic fever episode.
In severe cases, the valves ultimately have to be replaced with artificial ones. People with damaged valves and those with an artificial heart valve are at increased risk of a heart infection later in life (infectious endocarditis).
The central nervous system may also be affected to produce a symptom known as chorea. Chorea affects females more frequently and almost never occurs after puberty. The onset of chorea is usually gradual, and it often first appears several months after the rheumatic fever has passed. Occasionally, chorea is the only visible symptom of rheumatic fever. Teachers may be the first to notice it and mistake it for clumsiness or restlessness. Symptoms of chorea may include:
- muscular weakness
- involuntary, purposeless movements of the arms and legs
- emotional disturbances (crying and restlessness)
Rheumatic fever can also cause skin lesions to develop. These can be firm and painless nodules under the skin that can be present for one or more weeks, or non-itching rashes (called erythema marginatum) that usually affect the trunk of the body and appear and disappear within hours.
Making the Diagnosis
The actual quantity of bacteria in the systems of people with rheumatic fever is often so low that the bacteria are undetectable. Doctors rely on a standardized checklist to identify the disease.
If you have a recent history of streptococcal infection, and at least 2 symptoms from a list of 5 common symptoms: arthritis, chorea, erythema marginatum, nodules under the skin, and carditis, your doctor may diagnose you with rheumatic fever.
Your doctor will listen to your heart with a stethoscope to help detect carditis. The diagnosis can also be made with only one of these common symptoms if other abnormalities are present at the same time. These include: sore joints, fever, rheumatic fever in the past, a specific abnormality on electrocardiogram (ECG; prolonged PR interval), or specific abnormalities on blood testing (elevated C-reactive protein or sedimentation rate).
Certain tests can also support the diagnosis by detecting antibodies the body produce against the Streptococcus bacteria, or by detecting the bacteria itself.
Before making any treatment decisions, your doctor will want to rule out other conditions that can affect the heart. Tests like the echocardiogram (ultrasound of the heart) can reveal the presence of congenital heart defects that might be confused with rheumatic fever.
Treatment and Prevention
The best way to prevent rheumatic fever is to have strep throat treated promptly with penicillin* or other antibiotics. The strep infection should be confirmed with a throat swab before treatment is started, and rheumatic fever will be prevented as long as treatment is started within 5 or 6 days. Therefore, there is time to safely wait for the swab result. The main reason to treat strep throat is to prevent rheumatic fever. Pain killers, hot drinks, and gargling would also help the sore throat, but only the antibiotics can kill the bacteria and make the symptoms disappear.
Although bacteria are responsible for triggering rheumatic fever, antibiotics can do little to help once you have rheumatic fever, and treatment then aims at relieving symptoms. The normal treatment for joint inflammation and pain in rheumatic fever is the use of nonsteroidal anti-inflammatory drugs (NSAIDs).
Because people who've had rheumatic fever are more prone to further attacks if they get another strep infection, they may be given monthly intramuscular penicillin or daily penicillin treatment by mouth, perhaps for life. If their heart has been damaged by rheumatic fever, they're also given a different antibiotic when they undergo any dental or surgical procedures to reduce the risk of bacterial heart valve infection (endocarditis).
There's no treatment that will make chorea go away more quickly, though children with chorea are often given antibiotics to prevent endocarditis. Fortunately, the symptoms of chorea often disappear within a few months, although sometimes they may take a year or more to go away.
The rash and the nodules usually clear up on their own.