Abstract
Erythema multiforme (EM) is an immune-mediated condition that classically presents with discrete targetoid lesions and can involve both mucosal and cutaneous sites. While EM is typically preceded by viral infections, most notably herpes simplex virus (HSV), and certain medications, a large portion of cases are due to an unidentifiable cause. EM can be confused with other more serious conditions like Stevens-Johnson syndrome (SJS); however, clinical research has provided significant evidence to classify EM and SJS as separate disorders. Treatment of EM is highly variable, depending on the etiology, the involvement of mucosal sites, and the chronicity (acute vs. recurring) of the disease. If the etiology or causal medication/infection is identified, then the medication is stopped and/or the infection is treated prior to initiating symptomatic treatment. Treatment for acute EM is focused on relieving symptoms with topical steroids or antihistamines. Treatment for recurrent EM is most successful when tailored to individual patients. First line treatment for recurrent EM includes both systemic and topical therapies. Systemic therapies include corticosteroid therapy and antiviral prophylaxis. Topical therapies include high-potency corticosteroids, and antiseptic or anesthetic solutions for mucosal involvement. Second-line therapies for patients who do not respond to antiviral medications include immunosuppressive agents, antibiotics, anthelmintics, and antimalarials.