How does rheumatic fever develop?
Group A beta-hemolytic streptococcus causes sore throat and pharyngitis. In predisposed people, the immune response to streptococcal proteins is cross-directed to their own tissues, similar in structure - this mechanism is called molecular mimicry. Inflammation affects the connective tissue of the heart, joints, brain and skin. The disease does not develop during a sore throat, but 2–4 weeks after it. Repeated streptococcal infections can cause another attack, and with each episode the risk of severe damage to the heart valves increases. Skin streptococcal infections usually do not cause rheumatic fever.
- Rheumatic carditis - inflammation of the lining of the heart, most often the valves
- Migratory polyarthritis of large joints
- Lesser chorea - damage to the nervous system
- Ring-shaped erythema on the skin
- Subcutaneous rheumatic nodules
- Chronic rheumatic heart disease as an outcome
Causes and risk factors
The only immediate cause is a previous streptococcal throat infection. Not everyone develops the disease: hereditary predisposition matters, so it is more common in some families. The most vulnerable age is from 5 to 15 years. The risk is higher with crowded living conditions, frequent sore throats, and the absence or incomplete course of antibiotics for streptococcal tonsillitis. Self-treatment of sore throat without a doctor, stopping taking antibiotics after feeling better are common mistakes that increase the likelihood of complications.
- Streptococcal sore throat or pharyngitis
- Lack or incomplete course of antibiotics
- Age 5–15 years
- Hereditary predisposition
- Crowding in family and groups
- Previous attack of rheumatic fever
Symptoms
A few weeks after a sore throat, the temperature rises, weakness and sweating appear. Migratory arthritis is characteristic: large joints - knees, ankles, elbows - alternately become red, swollen and very painful, inflammation moves from one joint to another within a few days. Heart damage can manifest itself as rapid heartbeat, shortness of breath, and chest pain, but it often goes unnoticed and is detected only during examination. Minor chorea develops later and is manifested by involuntary movements, grimaces, awkwardness, and tearfulness. Pale pink ring-shaped spots may appear on the skin.
- Fever and weakness after a sore throat
- Migrating pain and swelling of large joints
- Palpitations, shortness of breath, chest pain
- Heart murmur detected by a doctor
- Involuntary movements and emotional instability
- Ring-shaped rash
- Subcutaneous nodules near joints
Diagnostics
The diagnosis is made based on a combination of clinical signs and examination data using international criteria. Be sure to look for evidence of a recent streptococcal infection: an increase in antistreptolysin-O titer, a positive smear or rapid throat test. Blood tests show signs of inflammation - increased ESR and C-reactive protein, leukocytosis. The ECG reveals prolongation of the PR interval and rhythm disturbances. The key test is Doppler echocardiography: it detects valve damage even in the absence of a heart murmur. Similar complaints occur with other arthritis, so the doctor rules them out.
- Complete blood count, ESR
- C-reactive protein
- ASLO
- Throat swab or rapid test for streptococcus
- ECG
- Echocardiography with Dopplerography
Treatment and prevention
Treatment is carried out under the supervision of a doctor, in the acute phase often in a hospital. Antibiotics are prescribed to destroy streptococcus, anti-inflammatory drugs to reduce arthritis and inflammation of the heart, and for severe carditis - additional medications. During the active period, a limited load regime is needed. After the attack, secondary prevention is carried out: long-term, sometimes many years of regular administration of a penicillin antibiotic to prevent re-infection. Primary prevention is complete treatment of streptococcal sore throat with antibiotics as prescribed by a doctor. People with valve defects are monitored by a cardiologist for life.
- Consult a doctor for every sore throat in a child
- Take full course of antibiotics
- Do not interrupt secondary prevention after an attack
- Regular echocardiography for heart disease
- Treatment of caries and chronic foci of infection
- Observation by a rheumatologist and cardiologist