Gyrate erythema in the setting of tinea pedis.

Gyrate erythema, which also is known as erythemaannulare centrifugum (EAC), is a reactive dermatitisthat is thought to occur in response to an underlyingtrigger. The superficial form is characterized bythe typical, centrifugally-expanding, annular,erythematous patches or plaques with a distincttrailing scale. The deep form also is a centrifugallyexpanding,erythematous plaque but with induratedborders and absence of scale. These cutaneousfindings are thought to be reactive, most often inresponse to infections or drugs and, less likely, tounderlying malignant conditions.