Erythema Annulare Centrifugum

Abstract

Erythema annulare centrifugum is classified generally into a superficial and a deep type. Whether those types are variants of the same process or unrelated to one another, and whether they represent non-specific patterns or specific clinico-pathologic entities, is controversial. To answer those questions, we analyzed 82 biopsy specimens from 73 patients with a clinical and histopathologic diagnosis of erythema annulare centrifugum, gyrate erythema, or figurate erythema regarding a variety of clinical and histopathologic findings. We found substantial differences between cases with a wholly superficial type and cases with a superficial and deep infiltrate. Clinically, a collarette of scales was seen only in the superficial type. Histopathologically, some findings were much more common in the superficial type (eg, spongiosis, parakeratosis, crusts, edema of the papillary dermis, epidermal hyperplasia) and others in the deep type (eg, sleeve-like arrangement of the infiltrate, melanophages, subtle vacuolar changes at the dermo-epidermal junction, individual necrotic keratinocytes). Whereas cases of the superficial type could be distinguished from differential diagnoses by a variety of clinical and histopathologic findings, most cases of the deep type showed subtle signs of lupus erythematosus. Neither type was associated consistently with any other systemic disease. Because the superficial and the deep type of erythema annulare centrifugum seem to be unrelated to one another, they should not be referred to by the same name. We believe that the term should be reserved for the superficial type because the latter seems to be a specific clinico-pathologic entity. By contrast, most cases of the deep type seem to be annular examples of tumid lupus erythematosus and should be diagnosed that way. If findings militate against the diagnosis of lupus erythematosus, we suggest using a descriptive term that signals non-specificity-namely, deep figurate erythema.