History:

Erythema annulare centrifugum (EAC) is a reaction pattern in the skin to a variety of underlying skin conditions including infections , particularly fungal, collagen diseases, internal malignancy, food sensitivity, drugs etc. The deep variant histologically does not show scale but the more superficial variant with spongiosis as well as the tight perivascular lymphocytic variant will show a trailing scale behind the advancing edge of the ring.

See Dermnet