Clinicopathologic analysis of 66 cases of erythema annulare centrifugum.

Erythema annulare centrifugum (EAC) denotes a group of eruptions characterized by slowly migrating annular or configurate erythematous lesions. It can be classified histopathologically as the deep or superficial type. Although there are many case reports of EAC associated with various underlying conditions, no recent clinicopathologic studies exist. The purpose of this study was aimed at analyzing the clinical and histopathologic features of EAC. Sixty-six patients who have been diagnosed as EAC by clinical and histopathological examination were collected. The medical records and skin biopsy specimens of these patients were reviewed retrospectively. There were 24 male patients and 42 female ones. The mean age was 39.7 years, and the mean durtion of the disease was 2.8 years. The lower extremities, particularly the thigh, were the most frequently involved locations. The most common clinical manifestation was large (>1 cm), scaly, erythematous, indurated plaques. Forty-eight patients (72%) had combined diseases including cutaneous fungal infection (48%), such as tinea pedis, other skin diseases (18%), internal malignancies (13%), and other systemic diseases (21%). By histopathologic examination, 33 of 42 patients (78%) were identified as superficial type, and 9 patients (22%) were deep type. Therapeutic trials with systemic or topical corticosteroid and oral antihistamine did not affect the chronic and recurrent course of these patients. EAC is a chronic and recurrent disease despite treatment. EAC is thought to be highly associated with internal disease as well as with superificial fungal infection. However, it was difficult to prove a causal association. The recognition and exact diagnosis of EAC is important, because it may be a quite stressful condition and lead to unnecessary over-treatments.