Severe Cutaneous Adverse Reactions to Drugs

Abstract

Abstract The severe cutaneous adverse reactions (SCARs) are drug allergy syndromes characterised by a dermatosis and significant internal organ involvement which confers a risk of systemic morbidity and mortality. The major entities classified as SCARs are: acute generalised exanthematous pustulosis (AGEP), drug reaction with eosinophilia and systemic symptoms (DRESS) and Stevens–Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). The toxic dermatitis of AGEP is complicated by sheets of tiny pustules; DRESS is distinguished by an urticated exanthem, facial oedema, atypical targets and purpura; in SJS/TEN there is multisite mucositis and a blistering dermatosis resulting in widespread epidermal loss. Severe DRESS can be complicated by liver failure, whereas in SJS/TEN large insensible fluid losses, thermoregulatory dysfunction, metabolic stresses and sepsis can complicate skin loss. Management of all the SCAR syndromes depends on the immediate cessation of the culprit drug and the institution of supportive therapy and, when appropriate, active treatment.