Rheumatic fever is an autoimmune disease that affects the heart, joints, skin, and brain. It occurs as a result of a streptococcal throat infection and abnormal immune response in genetically susceptible individuals. The disease is most common in children aged 5-15 years from developing countries. It can lead to long term heart complications such as rheumatic heart disease if untreated. Prevention involves proper treatment of streptococcal infections with antibiotics.