In summary, the diagnosis of erythema multiforme is appropriate for a self-limiting or episodic cutaneous or mucocutaneous illness with skin lesions morphologically and histologically compatible. With typical erythema multiforme minor, characterized by classic skin lesions with or without oral erosions, most patients' disease is associated with recurrent herpes simplex infections. This is particularly true with recurrent erythema multiforme. Symptomatic conservative care, antibiotic treatment for purulent secondarily infected oral lesions, and avoidance of systemic steroids are appropriate therapeutic guidelines. The more serious syndrome, erythema multiforme major, or Stevens-Johnson syndrome, is characterized by skin lesions that are somewhat atypical and different from those of erythema multiforme minor in association with erosions on multiple mucosal surfaces. Drugs and mycoplasmal infections are important precipitating factors for erythema multiforme major. Hospitalization and laboratory tests are often required because of the severity of the illness and the occasional damage to other organ systems. Conservative, symptomatic care, withdrawal of any drug that may have caused the illness, treatment of any mycoplasmal infection, and antibiotic therapy for purulent secondarily infected lesions are worthwhile therapeutic measures. Early treatment with systemic steroids may be helpful in preventing further damage, and the risks and potential benefits of such therapy must be evaluated on an individual basis.