Erythema Multiforme: A Mysterious Lesion!

The term " erythema multiforme (EM)" includes a wide and controversial variety of clinical expressions at the present time. This study revises the EM minor characteristics according to the most important publications found in literature. EM is a distinct dermatologic hypersensitivity pathology characterized by cutaneous or mucous lesions, and eventually, it can also involve both. In the EM minor, only one mucous membrane is affected and usually is the oral mucosa. When occur in the skin, the lesions usually appear symmetrically in the extremities and may exhibit several forms; hence, the name EM, in a target form, could be continuous or recurrent and none additional systemic involvement is present for both cases. Nowadays, many authors separate etiologically the several manifestations of the EM spectrum. However, no clinical definition is still accepted thoroughly, making more difficult the comparisons of etiological and clinical aspects, histopathological studies, and therapeutic protocols. For the present work, we tried to elucidate through an extensive literature revision, some historical and current aspects of EM, focusing mainly the EM minor and its frequent association to herpes simplex virus, with their diagnostic characteristics and current therapeutics, to facilitate the physician understanding, and to favor future researches about this mysterious disease.