Skin involvement in toxic epidermal necrolysis?

Ans. is 'd' i.e., > 30% Erythema multiforme It is an acute , often self limited eruption characterized by a distinctive clinical eruption, the hallmark of which is target lesions (Iris lesions). EM can present with wide spectrum of severity which can be classified into 1. Erythema multiforme minor It is simply referred to as erythema multiforme (i.e. if not specified about other 2 types, erythema multiforme means EM minor). Localized eruption of skin with or without mucosal involvement. 2. Steven- Johnson syndrome (SJS) There are mucosal erosions with pruritic macules. In this epidermal detatchment is 10-30% of the body surface area. 3. Toxic epidermal necrolysis (TEN) When skin detachment is more then 30% of BSA. It is also called Lyell's syndrome. Therefore TEN & SJS are considered as single syndrome i.e. SJS-TEN syndrome (Erythema multiforme major). If area involved is more than 30% it is TEN & if area involved is 10-30%, it is SJS.