Rationale: Erythema multiforme (EM) is an immune-mediated disease with mucocutaneous localization and plurietiologic determinism. The term "multiforme" refers to the variety of aspects that the lesions can take from patient to patient and during evolution in a single patient.
Patient concerns: We have selected 2 cases of small children diagnosed with different etiology of EM to illustrate the importance of a correct and fast diagnosis. Case 1 involves a 2-year-old girl from a rural area who presented with fever and pruritic erythematous papular eruption. The onset of the symptoms was 3 days before presentation with fever and ulcerative lesions on the oral and labial mucosa, followed by the appearance of erythematous macular lesions, with progressive confluence to intense pruritic patches. The 2nd involves a 2-year-old boy with fever, loss of appetite, productive cough, and petechiae. He had corticosensible immune thrombocytopenia from the age of 6 months, with many recurrences. The patient received treatment with ampicillin/sulbactam and symptomatics for an erythemato-pultaceous angina. During the 2nd day of treatment the patient developed an erythematous macular eruption on the face, scalp, trunk, and limbs, with bullae formation.
Diagnoses: The 1st patient was diagnosed based on biologic findings: positive inflammatory syndrome, elevated level of anti-Mycoplasma pneumoniae immunoglobulin M antibodies and immunoglobulin E. Histopathologic examination described papillary dermal edema, inflammatory infiltrate, and lymphocyte exocytosis. In the 2nd case, the hemoleucogram identified 12,000/mm platelets and the medulogram aspect was normal. Serology for Epstein-Barr virus was negative. The diagnosis was EM secondary to M pneumoniae infection in case 1 and secondary to administration of ampicillin/sulbactam in case 2.
Interventions: In both cases, etiopathogenic treatment consisting of steroidal antiinflammatory drugs, antihistamines was administered. Because of specific etiology, the 1st case received antibiotics.
Outcomes: The evolution was favorable in 10 to 14 days; the patients were discharged after etiopathogenic treatment consisting of steroidal antiinflammatory drugs, antihistamines, and/or antibiotics.
Lessons: Performing a detailed clinical examination, medical history of drug use, infection or general diseases can establish a good diagnosis of EM. Histopathologic examination can help. The treatment is etiologic, pathogenic, and symptomatic. EM usually has a self-limited evolution.