Erythema Multiforme Major

**Semantic type:** Disease or Syndrome

**Definition:** A severe, sometimes life-threatening, form of erythema multiforme. It is considered to be a hypersensitivity skin reaction triggered by a variety of stimuli, including infections and medication. It is characterized by raised, edematous papules in the extremities; involvement of one or more mucous membranes; and epidermal detachment involving less than ten percent of the total body surface area.