Rheumatic Fever, Acute
What is acute rheumatic fever?
Acute rheumatic fever is a disease that affects the body's connective tissue and central nervous system. It results from a throat or tonsil infection that is caused by group A beta hemolytic streptococci, commonly referred to as "strep throat." Rheumatic fever is a side effect of the strep infection, not part of the infection itself. Rheumatic fever affects the heart; the joints; the skin, i.e., an unusual rash called erythema marginatum, and subcutaneous nodules, which are small, pea-sized nodules under the skin; or the central nervous system, i.e., Sydenham's chorea, commonly known as St. Vitus dance.
Rheumatic fever is the result of a streptococcal sore throat; therefore, it is important to prevent and/or treat this infection. Usually, antibiotic treatment prevents rheumatic fever. Although the exact way in which rheumatic fever develops is not understood, it is believed that the patient who develops rheumatic fever (about 3% of patients with untreated strep throat) have an abnormal immune response to some part of the group A streptococcus. Most likely, this is because some parts of the bacteria are almost identical to certain parts of the human heart and other human tissues. This is thought to result in the body essentially reacting against itself (called "auto-immunity" or "antigenic mimicry").
Who gets rheumatic fever?
Group A streptococcal upper respiratory tract infections are very common among children. Most patients who develop rheumatic fever are in the age range between 5 and 15 years. It is rare for very young children (less than three or four years of age), as well as adults, to develop rheumatic fever, even if they have a strep infection. However, young adults are susceptible. While there is a genetic predisposition (i.e., it "runs in families") to developing rheumatic fever, reasons for this are not completely understood.
How does it cause disease?
The symptoms of a strep infection include a sudden onset of a very sore throat with a high fever. Nausea and abdominal pain may occur in children. However, many patients who develop strep throat do not develop these classic symptoms. An abnormal immune response by the body, following a period of approximately 10 days to 2 weeks after the strep infection, is believed to cause the clinical signs of rheumatic fever.
The signs and symptoms of rheumatic fever depend on which body systems are affected. In approximately half of the patients with rheumatic fever, the heart is involved. Patients may develop the symptoms of heart failure, such as shortness of breath. Leaking ("incompetence") of one of the heart valves results in a heart murmur, which can be heard by a physician.
The arthritis of rheumatic fever is not chronic arthritis. It usually occurs in 60% to 70% of patients. It usually affects large joints, such as elbows, wrists, shoulders, ankles, and knees. It rarely affects the fingers, the spine, or the hips. It is called a "migratory arthritis" because in the untreated patient, it will affect one joint one day and move on to another joint a day or so later. It is important that the migratory nature of the arthritis be documented before making this diagnosis.
Sydenham's chorea, or St. Vitus dance, is much less common than arthritis or rheumatic heart disease, occurring in only 10% to 15% of patients. Patients may develop clumsiness. Emotional changes often may occur. Typically, findings in children are first noted either at the dinner table, where they find it difficult to use utensils and frequently spill milk, or by a schoolteacher, who notices emotional changes and a deterioration in handwriting and other fine motor skills.
The rash of rheumatic fever, called erythema marginatum, is uncommon, and it is seen in only about 5% to 8% of patients. The rash occurs mainly on the trunk; is circumscribed, i.e., confined to a limited space; is not painful; and does not itch.
The subcutaneous nodules of rheumatic fever also are very rare, except in those individuals who have severe heart valve involvement. These are small, pea-sized nodules, which are often on the back of the hand over the knuckles and on the outside of the elbow joint.
How is rheumatic fever diagnosed?
Physicians diagnose rheumatic fever based on a clinical examination, since there is not a single laboratory test that can diagnose it. Clinical criteria, called the Jones Criteria, take into account the most common findings of patients with rheumatic fever. Thus, physicians may use the Jones Criteria to diagnose rheumatic fever. However, the Jones Criteria can be difficult to apply; many diseases may appear to fulfill the Jones Criteria, but are not rheumatic fever. There are five major criteria (carditis, arthritis, chorea, erythema marginatum, and subcutaneous nodules). Less specific findings, called minor criteria, include fever, aching (not arthritis) of the joints, and several very non-specific laboratory tests. The presence of two major criteria or one major and two minor criteria, plus a recent strep infection, should lead to a possible diagnosis of rheumatic fever.
Initially, the treatment of rheumatic fever focuses on the therapy of the group A streptococcal infection, which still may be present at the time that rheumatic fever develops, and, then, it focuses on the clinical symptoms of the disease. Treatment of the sore throat in patients with rheumatic fever is very important. Most often, penicillin (or sometimes another antibiotic) is used to treat the sore throat. Penicillin may be given either orally or by injection.
The treatment of the heart disease depends on its severity. Often, either corticosteroids or aspirin are used. If a patient shows signs of a failing heart ("congestive heart failure"), drugs that strengthen the contraction of the heart, and drugs that help to eliminate excess fluids from the body (diuretics), may be used. While steroids may help the acute phase of the heart disease, if there is heart failure, they do not prevent the development of heart valve disease.
The arthritis of rheumatic fever, while very painful, can be controlled with aspirin ("salicylates"). In fact, once aspirin is started in patients with rheumatic fever, it is common for the arthritis to completely subside in 12 to 24 hours. It is thought that if the arthritis does not disappear quickly after beginning treatment with aspirin, the diagnosis of rheumatic fever should be questioned. Steroids are almost never used to treat the arthritis of rheumatic fever. In the acute phase, the pain of the arthritis can be controlled by any number of pain medications available to a physician.
The treatment of Sydenham's chorea is more difficult. Specific medications are available that help to reduce the uncontrollable neurological movements of this disease. However, the signs and symptoms of Sydenham's chorea may persist as long as several months, even when appropriate medications are used.
Treatment is not needed for either the rash or the small, painless subcutaneous nodules.
The main complication of rheumatic fever is rheumatic valvular heart disease. Approximately 50% (but in some instances, more) of patients will develop scarring of the heart valves. Usually, it is the mitral valve (between the left atrium and the left ventricle), but, sometimes, it involves the aortic valve (the valve that directs blood to the body). Rarely, the valves on the right side of the heart (those to the lungs) are affected. When the heart valves become so damaged and cause heart failure, surgery is needed. Often, an artificial heart valve is required. The arthritis associated with rheumatic fever disappears, and it is not a chronic complication. Sydenham's chorea may recur in patients who have rheumatic fever, but it usually is not a continuing problem. The other symptoms do not cause long-term complications.
There are two types of prevention for rheumatic fever: primary prevention and secondary prevention.
Primary prevention means the appropriate diagnosis and treatment of strep throat, thereby preventing an initial attack of rheumatic fever. Usually, this treatment is with penicillin or similar antibiotics (e.g., amoxicillin). Other drugs, such as erythromycin or some of the cephalosporins, can be used effectively. Erythromycin is used mainly for those individuals who are allergic to penicillin. Penicillin may be given either orally for 10 days or by injection. Although shorter courses (less than 10 days) of antibiotics are thought to be equally effective, most professional organizations recommend the full 10 days of oral antibiotic therapy.
Secondary prevention means the prevention of a second or third attack of rheumatic fever in an individual who has already had the disease. In contrast to primary prevention, which is given only at the time of a strep infection, secondary prevention is continuous. The duration of secondary prevention depends on numerous factors; however, it is usually for at least five years and, frequently, for longer periods of time. Secondary prevention requires careful consideration by a physician. These patients may be given either oral penicillin on a daily basis or injections of a long-acting form of penicillin, called benzathine penicillin G, on a monthly basis. Studies have shown that the injection, while painful in some cases, is more effective in preventing patients from recurrent rheumatic fever. Oral sulfa drugs also may be used for secondary prevention, but not primary prevention, of rheumatic fever.
Research in rheumatic fever, which still is a major cause of heart disease in many parts of the world, focuses on two objectives. The first objective is to more completely understand how the strep infection starts the reaction that results in rheumatic fever. The mechanisms that cause rheumatic fever remain poorly understood. Since control of any disease process is most effective when the cause of the disease is known, this research is important. Whether rheumatic fever is affected by a particular kind of streptococcus that causes the throat infection or whether there are genetic predispositions to developing rheumatic fever remains to be fully understood.
Another current and important area of research is the use of a vaccine to prevent strep infections. Public health programs that use vaccines (e.g., measles) successfully are very cost effective. Unfortunately, the preparation of a vaccine against group A streptococci is more difficult because some parts of streptococcus are similar to some parts of human tissue, and because there are many different types of group A streptococci. A cost-effective vaccine against many types of streptococci would have important public health implications. Studies to develop test vaccines are in progress.
Research is important to better understand how a strep infection is spread, why this infection most often affects children, and how to best diagnose and treat the infection in a cost-effective manner.
About the Author
Dr. Kaplan has been interested for many years in streptococcal infections and their reguelae. He is a renowned authority on Acute Rheumatic Fever and the associated complications.
Copyright 2012 Edward L. Kaplan, M.D., All Rights Reserved