NOT ALL the etiologic factors involved in the causation of erythema multiforme are as yet clear. It is also true that in the therapeusis of this dermatosis success is occasionally difficult to obtain. Because of these facts, an analytic study was made of 40 unselected patients having typical erythema multiforme exudativum. Six of these patients had accompanying bullous lesions. In view of the close relationship between erythema multiforme and erythema nodosum, 14 additional patients with the latter disease were also studied for comparison. Examples of both types of lesions were not exhibited by any one patient in this study.
The 54 patients were examined carefully, and every attempt was made to evaluate thoroughly the background, the history, the physical findings and the accessory clinical findings in each patient. In addition to inquiry being directed to age, sex, race, temperature, systemic symptoms, family history, season of incidence, occupation, duration