Erythema multiforme major

In dermatology, erythema multiforme major is a form of rash with skin loss or epidermal detachment.
The term "erythema multiforme majus" is sometimes used to imply a bullous presentation.
According to some sources, there are two conditions included on a spectrum of this same disease process:

Stevens–Johnson syndrome
Toxic epidermal necrolysis which described by Alan Lyell and previously called Lyell syndrome.

In this view, EM major, SJS and TEN are considered a single condition, distinguished by degree of epidermal detachment.
However, a consensus classification separates erythema multiforme minor, erythema multiforme major, and SJS/TEN as three separate entities.