Rheumatic fever is an inflammatory condition where the immune system attack’s the body’s healthy tissue due to a cross reaction after a streptococcal infection usually of the throat (strep sore throat). It characteristically tends to recur. Rheumatic fever can follow an inadequately treated streptococcal throat infection. The disease is common is children between the ages of 5 to 15 years though it may be seen in others. It is rare in the United States but is fairly common in developing countries due to inadequate treatment for strep throat. Rheumatic fever can cause irreversible damage of the heart muscle or valves and treatment may be necessary for a lifetime.
Symptoms can be categorized as major and minor symptoms.
- Carditis. Inflammation of the muscles of the heart or the membrane covering the heart.
- Polyarthritis. Joint inflammation usually knees, ankles and elbows. The arthritis tends to move from one joint to other.
- Chorea. Involuntary abrupt movements of limbs. The child may cry or laugh inappropriately.
- Erythema marginatum. A painless rash that looks like smoke rings.
- Subcutaneous nodules. Painless, roundish firm lumps over otherwise normal skin.
- Chest pain.
Diagnostic tests may reveal :
- Elevated ESR.
- CRP positive.
- Prolonged PR interval in EKG.
One of the major conditions in rheumatic fever is damage to the heart, which is known as rheumatic heart disease. The inflammation of causes damage of the heart muscle and valves leading to endocarditis, myocarditis or pericarditis or combination of all (pancarditis). The patient can develop fluid collection in the sac surrounding the heart (pericardial effusion). The damage of the valves can impair the amount of blood flow to the body. Murmurs may be heard. Congestive heart failure is the most serious but a rare manifestation of rheumatic fever. Atrial fibrillation can occur.
Rheumatic fever usually follows a streptococcal throat infection or sometimes scarlet fever which is caused due to the organism Streptococcus pyogenes, usually if the infection is not treated adequately.
The cell membrane of this organism contains biological components that are also found in the tissues of the heart and other organs. Therefore when the immune system is working against the infection it also reacts with the tissues of the heart thereby damaging of the heart tissue giving rise to rheumatoid carditis. This cross-reaction is also found on brain tissues in people with chorea.
Certain genetic factors can predispose a person to develop rheumatic fever. The disease is common in socially disadvantaged populations where there are overcrowded living conditions and poor sanitation.
Treatment consists of first completely eradicating of the infection with the use of appropriate antibiotics. Anti-inflammatory drugs like aspirin or naproxen is very effective in suppressing the acute inflammatory symptoms of rheumatic fever. Aspirin should be avoided in children. Crticosteroids (prednisolone) may be used if anti-inflammatory drugs are not sufficiently effective. It may be necessary to receive antibiotic treatment for a longer duration of times to prevent recurring episodes of rheumatic fever. Chorea can be treated with anticonvulsant medications such as carbamazepine and valproic acid.