Gyrate erythema.

The gyrate erythemas consist of a nonspecific group (often called erythema annulare centrifugum) for which the cause is usually unknown, and three specific types (erythema marginatum rheumaticum, erythema chronicum migrans [Lyme disease], and erythema gyratum repens). The first specific type, erythema marginatum rheumaticum, has become extremely rare with the decline of its associated disease, rheumatic fever. The second specific type, erythema chronicum migrans, is caused by a spirochete transmitted by the I. ricinus complex of ticks. The third specific type, erythema gyratum repens, is uncommon, morphologically distinctive, and an indicator of serious disease, usually internal malignancy, in almost every instance.