Different individuals may respond diversely to the same drug, in terms of efficacy and toxicity. Adverse drug reactions cause about 6% of all hospital admissions and account for up to 9% of hospitalization costs. Drug-induced skin injury (DISI) is the most common presentation of adverse drug reactions, ranging from maculopapular eruptions to severe adverse cutaneous drug reactions (SCARs) with mortality of up to 40%. Specific genetic polymorphisms confer susceptibility to different types of DISI. Identifying patients genetically at risk for SCARs is one of the goals of pharmacogenomics. In this article, the aspects of clinical dermatology relevant to the pharmacogenetics of DISI are reviewed. Many SCARs are now preventable, with consequent reduction of morbidity, mortality and healthcare costs.
Keywords: HLA; Stevens–Johnson syndrome; acute generalized exanthematous pustulosis; cutaneous adverse drug reaction; drug reaction with eosinophilia and systemic symptoms; drug-induced skin injury; hypersensitivity syndrome; pharmacogenetic; toxic epidermal necrolysis.