Causes Of Rheumatic Fever

Rheumatic fever is caused by a response of the body's defense system known as the immune system. Rheumatic fever may develop after strep throat or scarlet fever infections that are not treated properly. Bacteria called group A Streptococcus or group A strep cause strep throat and scarlet fever. It usually takes about 1 to 5 weeks after strep throat or scarlet fever for the rheumatic fever to develop.