What is rheumatic fever?
A disease that can result from inadequately treated strep throat or scarlet fever. Rheumatic fever is an inflammatory disease that can develop when strep throat or scarlet fever isn't properly treated. Rheumatic fever is a complication of strep throat. Rheumatic fever (acute rheumatic fever) is a disease that can affect the heart, joints, brain, and skin. A rare but potentially life-threatening disease, rheumatic fever is a complication of untreated strep throat caused by bacteria called group A. Rheumatic fever is a serious disease caused by untreated strep throat or scarlet fever.