It is called rheumatic fever because two of the commonest symptoms are fever and pain in the joints similar to that of rheumatism. Rheumatic fever is relatively common and occurs particularly among children between 5 and 15 years of age. Young adults in the early twenties are also susceptible, although less so.
Rheumatic fever is only one of several complications that can result from a streptococcal infection.
The connection between rheumatic fever and a previous streptococcal infection has been proved only indirectly. There is evidence that the symptoms of rheumatic fever may result from an antigen-antibody reaction to one or more of the products of the hemolytic streptococcus, but the exact way in which this occurs is not known. Rheumatic fever tends to run in families, and there may be a hereditary predisposition to the disease. Economic and environmental conditions such as damp, cold climate and poor health habits may be contributing factors. The initial symptoms usually appear 1 to 4 weeks after the streptococcal infection has occurred.