Rheumatic Fever

Overview

Rheumatic fever is a serious inflammatory condition that can develop as a complication of untreated or inadequately treated streptococcal throat infections. In some people who have a streptococcal throat infection, the immune system mistakenly targets the body's own tissues. This abnormal immune response can affect the heart, joints, brain, and skin.

The most important and most lasting effect of rheumatic fever is on the heart. The condition can damage the heart valves and the inner lining and muscle of the heart, causing permanent injury. This is called rheumatic heart disease and remains one of the leading causes of acquired heart valve disease in young people in developing countries.

Rheumatic fever most commonly affects children between the ages of five and fifteen. Because repeated attacks progressively worsen cardiac damage, prevention and early treatment are critically important. Prompt antibiotic treatment of streptococcal throat infections can largely prevent rheumatic fever from occurring.

Symptoms

The symptoms of rheumatic fever typically appear two to four weeks after a streptococcal throat infection. They can vary considerably from person to person, and not every patient develops all of the features.

• Fever. A sustained but often not very high temperature is commonly present.
• Joint pain and swelling. This is one of the most common findings. Large joints are primarily affected: most often the knees, ankles, elbows, and wrists. The pain characteristically moves from one joint to another, a pattern called migratory arthritis that is quite specific to rheumatic fever. Affected joints may be red, swollen, and very tender to touch.
• Cardiac symptoms. When the heart is involved, shortness of breath, chest pain or pressure, and palpitations may develop. In some cases, cardiac involvement is clinically silent and detected only through examination or imaging. Heart involvement is the most serious dimension of rheumatic fever.
• Sydenham's chorea. This is the neurological manifestation of rheumatic fever. Rapid, involuntary, purposeless movements of the arms, legs, or face occur beyond the person's control. These movements worsen with stress and disappear during sleep. Emotional instability and difficulty with coordination can also be present.
• Skin rash. A distinctive rash called erythema marginatum may appear on the trunk and limbs. It consists of pink or red rings with clear centers and well-defined edges. The rash is transient and may come and go over short periods.
• Subcutaneous nodules. Small, firm, painless lumps may be felt under the skin over bony prominences. These are uncommon.

When to Seek Medical Care

If a child or adult who has recently had a streptococcal throat infection develops any of the following, medical attention should be sought without delay.

• Joint pain or swelling appearing two to four weeks after a throat infection
• Unexplained fever
• Shortness of breath or palpitations
• Involuntary movement disturbances
• Chest pain or pressure

Causes

Rheumatic fever develops only after a Group A streptococcal throat infection. Streptococcal infections of the skin or other sites do not cause rheumatic fever. Several weeks after an untreated or inadequately treated streptococcal throat infection, the immune system mounts an abnormal response.

The underlying mechanism is a form of molecular mimicry. The antibodies the immune system produces to fight the streptococcal bacteria cross-react with the body's own heart valve tissue, because the surface structure of the bacteria resembles that of heart tissue. This triggers inflammation in the heart valves and can cause lasting scar tissue to form.

Not every streptococcal throat infection leads to rheumatic fever. The risk is influenced by whether the infection is treated, the individual's immune characteristics, and the specific strain of the bacterium.

Risk Factors

• Age. Children between five and fifteen are the most commonly affected group. The condition is less common in young children and adults but is not absent from these groups.
• Recurrent streptococcal throat infections. Each episode raises the risk of rheumatic fever, and a prior attack of rheumatic fever substantially increases the likelihood of recurrence with each subsequent streptococcal infection.
• Family history of rheumatic fever. A genetic predisposition appears to contribute in some people.
• Crowded living conditions. Streptococcal bacteria spread through close contact. Schools, dormitories, and crowded households increase the risk of infection.
• Limited access to healthcare. When streptococcal throat infections cannot be promptly diagnosed and treated with antibiotics, the risk of rheumatic fever rises significantly. This is why rheumatic fever is considerably more common in lower-income countries.

Diagnosis

The diagnosis of rheumatic fever is based on the combined assessment of clinical features, laboratory tests, and cardiac imaging. There is no single definitive test. Diagnosis follows internationally accepted criteria known as the Jones criteria, which define major and minor clinical and laboratory findings that must be present in combination.

• Medical history and physical examination. A history of sore throat or streptococcal infection in the preceding weeks is specifically sought. Joint findings, heart sounds, and skin changes are assessed in detail. A new murmur on cardiac auscultation may indicate carditis, meaning active inflammation of the heart.
• Throat culture and rapid streptococcal test. These tests look for active streptococcal infection in the throat. However, by the time rheumatic fever symptoms appear, the throat infection has often resolved spontaneously and these tests may be negative.
• Blood tests. The ASO titer (antistreptolysin O) measures antibodies produced against the streptococcal bacterium and provides evidence of a recent infection. Other streptococcal antibody tests such as anti-DNase B may also be used. Inflammatory markers including CRP and erythrocyte sedimentation rate are typically elevated. A full blood count and kidney function tests are also assessed.
• Echocardiogram (heart ultrasound). This is critically important for assessing whether the heart is involved. It can identify valve inflammation, backward leaking of blood through a valve, valve damage, and inflammation of the sac surrounding the heart. It can detect subclinical carditis (silent heart involvement) even when the physical examination appears normal. It is also used to monitor cardiac recovery following treatment.
• Electrocardiogram (ECG). Prolongation of the PR interval (a slowing of conduction between the upper and lower chambers) is a common finding in rheumatic fever. Rhythm disturbances may also be identified.

Treatment

Treatment of rheumatic fever has three core aims. The first is to eradicate the streptococcal infection. The second is to control the inflammatory symptoms. The third is to prevent recurrence and limit cardiac damage.

Eradicating the Streptococcal Infection

• Penicillin or amoxicillin. Antibiotics are started to treat Group A streptococcal infection, regardless of whether active infection is still present when the diagnosis of rheumatic fever is made. Alternative antibiotics are used in patients with penicillin allergy.

Controlling Inflammatory Symptoms

• Aspirin. Highly effective for controlling joint pain and inflammation. It is the first-choice anti-inflammatory agent for the joint manifestations of rheumatic fever. Treatment begins at a higher dose and is gradually reduced as symptoms resolve.
• Corticosteroids. When cardiac involvement is severe, particularly when fluid accumulates around the heart or significant valve inflammation is present, corticosteroids such as prednisolone are added to provide more powerful suppression of inflammation.
• Rest. Physical activity is restricted during active cardiac involvement. Activity is gradually reintroduced as the inflammation subsides.

Managing Sydenham's Chorea

When involuntary movement disturbances are present, providing a calm and low-stimulation environment is important. When symptoms are severe and significantly affecting the person's functioning, medication may be considered. Sydenham's chorea typically resolves on its own over weeks to months.

Preventing Recurrence: Long-Term Antibiotic Prophylaxis

This is the most critical dimension of rheumatic fever management. Repeated streptococcal throat infections can each trigger a new attack of rheumatic fever, progressively worsening cardiac damage. Long-term preventive antibiotic therapy is therefore recommended after a confirmed episode of rheumatic fever.

• Benzathine penicillin G. Given as an intramuscular injection every three to four weeks. This is considered the most reliable method because it does not depend on daily medication adherence.
• Oral penicillin or amoxicillin. A once-daily oral alternative that requires consistent daily use.
• Duration of prophylaxis. In people without cardiac involvement, prophylaxis is typically recommended for five years after the last attack or until the age of 21, whichever is longer. In those with cardiac involvement but no permanent valve damage, the duration extends to ten years or until age 25, whichever is longer. When permanent valve damage has occurred, prophylaxis into adulthood and in some cases lifelong continuation may be recommended. The precise duration is determined individually by the treating doctor.

Complications

The most important complication of rheumatic fever is permanent heart valve damage. Repeated attacks cause progressive worsening of this damage.

• Rheumatic heart disease. The most common and most serious long-term complication. The mitral valve is most frequently affected. Mitral stenosis (narrowing of the mitral valve) is the most characteristic manifestation of rheumatic heart disease. The aortic valve is the next most commonly affected. Valve damage can produce both narrowing and leaking and can progress over decades to heart failure, atrial fibrillation, and stroke.
• Atrial fibrillation. Enlargement of the left upper chamber as a consequence of valve damage predisposes to atrial fibrillation. This both worsens symptoms and raises the risk of stroke.
• Stroke. Clot formation related to atrial fibrillation can cause a stroke.
• Pericarditis. Inflammation of the sac surrounding the heart can occur during an acute attack, causing chest pain. This generally resolves with time but can occasionally result in significant fluid accumulation.

Prevention

Rheumatic fever is largely preventable. Prevention operates at two levels.

Primary Prevention

Promptly and fully treating streptococcal throat infections with antibiotics is the most effective way to prevent rheumatic fever. When sore throat and fever develop, seeking medical attention and completing the full prescribed course of antibiotics (even after symptoms resolve) is essential. Stopping antibiotics early allows bacteria to survive and increases the risk of rheumatic fever.

Secondary Prevention

For anyone who has already had rheumatic fever, long-term antibiotic prophylaxis is used to prevent recurrent streptococcal infections and thereby prevent further attacks of rheumatic fever. This prophylaxis is highly effective at preventing further cardiac damage and is the cornerstone of long-term management in people who have had the disease.

Lifestyle and Follow-up

People who have had rheumatic fever, particularly those with cardiac involvement, require long-term cardiology follow-up. Echocardiography is used at regular intervals to assess valve function and the state of the heart. The frequency of review depends on whether cardiac damage is present and its severity.

Taking antibiotic prophylaxis consistently without missing any doses is the single most important ongoing measure in this condition. Any sore throat or throat infection that develops during the prophylaxis period should be reported to the doctor promptly.

People with rheumatic heart disease should inform their dentist and every treating doctor about their cardiac condition. Antibiotic prophylaxis before dental procedures and certain surgeries may be recommended to reduce the risk of infective endocarditis.