Characteristics of pediatric recurrent erythema multiforme

Background: Erythema multiforme (EM) is an acute condition characterized by distinctive target lesions of the skin often accompanied by mucosal ulcers. A subset of individuals experience frequent episodes of recurrent EM, which is rare and poorly understood, especially in children. Objective: To characterize clinical features, laboratory findings, and treatment responses of pediatric recurrent EM. Methods: A retrospective chart review was conducted at the Children's Hospital of Wisconsin in Milwaukee, Wisconsin (2000-2015) and the Mayo Clinic in Rochester, Minnesota (1990-2015). Inclusion criterion was a diagnosis before age 18 years with recurrent EM, defined as a symmetrically distributed, fixed eruption, including target lesions, with or without mucous membrane involvement, occurring on at least three occasions. A literature review was conducted to include individuals who met the inclusion criterion. Results: Twenty-six patients were included, of whom 16 (62%) were male. The median age of onset was 9.1 years (range 0-15.7 years). Nine patients (35%) required hospitalization. Herpes simplex virus testing was positive in 9 of 17 (65%) patients. Remission was achieved in 5 of 16 (31%) patients while taking suppressive antivirals. Eight patients received continuous anti-inflammatory treatment, two (25%) of whom experienced remission. Conclusion: This study of pediatric recurrent EM found a greater male predominance, more hospitalizations, fewer cases caused by herpes simplex virus, and a lower response to immunosuppression in children than in the general population.