History:

This is one of the annular erythemas known as erythema annulare centrifugum.It is a reaction pattern in the skin with a variety of causes including drugs,other chemicals,coexisting fungal infection elsewhere,collagen diseases and even underlying malignancy.

The classic pattern shows the trailing scale lagging behind the advancing edge of the lesion.Always scrape these rashes for dermatophyte fungus anyway just in case you are misdiagnosing a Tinea corporis.This man had no obvious cause for his condition.The lesions would last 3 to 4 weeks then disappear for several months only to recur.