Erythema Multiforme, Stevens–Johnson Syndrome and Toxic Epidermal Necrolysis

Erythema multiforme, Stevens-Johnson syndrome and toxic epidermal necrolysis are a group of diseases characterized by varying degrees of skin and mucosal involvement. They are generally associated with drugs, although a proportion of cases of erythema multiforme, and to a lesser degree Stevens-Johnson syndrome, are attributed to certain infections such as the herpes simplex virus. These diseases were previously thought to be a single spectrum of disease, with erythema multiforme being the mildest and toxic epidermal necrolysis being the most severe. However, there is evidence to show that erythema multiforme is now considered a distinct entity, whilst Stevens-Johnson syndrome, Stevens-Johnson syndrome/toxic epidermal necrolysis overlap, and toxic epidermal necrolysis are variants of the same disease spectrum. As these conditions are quite rare and have associated significant morbidity, controversies exist in the management of the more severe variants, in particular, whether or not to give high-dose corticosteroids or intravenous immunoglobulin. This chapter will review these conditions and their current management.