Erythema Multiforme

Erythema Multiforme Minor

Target lesions

No mucosal involvement

least severe

Erythema Multiforme Major/SJS

Nikolsky sign

mucosal involvement

< 10% BSA

Toxic Epidermal Necrolysis

Nikolsky sign

mucosal involvement

most severe

How to differentiate between SJS and TEN?

amount of BSA

> 30% BSA is TEN

< 10% is SJS/erythema multiforme

between 10-30% is grey area