Misdiagnosis of erythema multiforme: a literature review and case report.

Erythema multiforme is primarily considered a disease of the skin. Diagnosis tends to be centered on dermatologic lesions of the extremities, with mouth ulcers regarded as a secondary finding. The purpose of this paper was to report a case of an 8-year-old male diagnosed with erythema multiforme limited to the oral cavity. The patient was referred to Texas A&M Health Science Center's Baylor College of Dentistry for biopsy of recurrent mouth ulcers following an outbreak of a fever blister. Previous hospitalization occurred twice due to severe mouth ulcers causing dehydration and loss of nutrition. He was treated with 10 mg of prednisone twice daily and was able to eat and drink without pain within 48 hours. Nearly all lesions healed within 5 days of therapy. Although rare, erythema multiforme should always be considered in the differential diagnosis in the event of acute onset stomatitis.