"Rheumatic fever licks the joints and bites the heart"
(old medical proverb)
The upper sentence suggests that rheumatic fever is a disease mainly affecting the heart and joints. It has a close relationship to streptococcal infections and it can cause numerous complications.
In developed countries, rheumatic fever is much rarer condition that it used to be in the past and the main reason is antibiotic therapy of streptococcal infections, especially tonsillitis. Before the era of antibiotics, the tonsillitis could no be treated effectively. Usually the disease was successfully healed by the immune system. However, in about two weeks, some patients began to suffer from symptoms of the rheumatic fever. What happened? It is simple. The immune system destroyed the infection, but the surface proteins of streptococcal cells are similar to other structures of the body and this triggered an immune reaction against these tissues. However, such autoimmune response occurs only in some people, probably due to some genetic precondition.
And which cells are commonly affected? Usually, the disease damages the cells of all three layers of the heart including endocardium (the inner membrane lining the heart atria and ventricles), myocardium (cells of the heart muscle) and pericardium (outer layer covering the heart). Very dangerous is the damage of cells of heart valves, which may result in valvular heart disease. Other damaged cells include cells in joints, cells in subcutaneous tissue and cells of blood vessel walls.
The disease has many manifestations. First symptoms are unspecific and they include fatigue, fever and overall malaise. Later symptoms are closely related to damage of particular organs:
Inflammations of multiple joints usually occur; the affected joints are red, painful and swollen.
Skin and subcutaneous tissues
The rheumatoid fever causes development of red rash known as erythema marginatum and occurrence of subcutaneous inflammatory nodules.
The mentioned symptoms and positive personal history of recent tonsillitis or another streptococcal infection (like erysipelas) are very suspicious. We can take a blood sample and state concentration of a substance known as ASLO (anti-streptolysin O). It is an antibody against streptococci and its elevated concentration in blood is present in periods after streptococcal infection. The heart may be examined by echocardiography.
The best prevention is to properly treat streptococcal infections with antibiotics as it significantly lowers the probability of following autoimmune response. Streptococci are still generally sensitive to good old penicillin. It is important to strictly follow both the prescribed dose and the time of administration.
If someone has already suffered an attack rheumatic fever, we try to prevent its return and such people are regularly (for years) administered daily doses of penicillin.
Upon detection of rheumatic fever, antibiotics are prescribed to destroy any remaining streptococci in the organism. Inflammatory response may be treated by anti-inflammatory drugs. Severe forms of the disease may be treated by corticosteroids. The therapy of heart arrhythmias and heart failure is done when needed.