Erythema multiforme: a case with unusual histopathological features.

A 14-year-old boy presented with widespread cutaneous and mucosal lesions clinically consistent with erythema multiforme. He gave a history of previous episodes of a similar eruption. Histological examination of a representative lesion showed changes consistent with erythema multiforme. It also, however, contained large numbers of eosinophils, forming a dermal interstitial infiltrate and epidermal microabscesses. The full blood examination showed a persistent eosinophilia. The appearances initially confused two experienced dermatopathologists.