erythema marginatum

Erythema marginatum is a skin rash characterized by reddening of the skin in disk-shaped areas with elevated edges. It is a characteristic sign of rheumatic fever, a rare inflammatory disease that can develop after an untreated streptococcal infection, primarily affecting children. While rheumatic fever can cause joint inflammation, its most significant danger is to the heart.1

Erythema itself is any abnormal redness of the skin caused by dilated and irritated superficial capillaries, leading to increased blood flow. Other types of erythema include erythema multiforme, with its distinctive target-like lesions, and erythema nodosum, which presents as painful nodules on the legs. Erythrasma is a separate superficial skin infection caused by bacteria, resulting in reddish-brown scaly patches.23