Making a diagnosis in severe cutaneous drug hypersensitivity reactions.

Abstract

Severe cutaneous adverse reactions (SCAR) are relatively uncommon but can be life-threatening. This review focuses on the nonanaphylactic (non-IgE-mediated) phenotypes of drug hypersensitivity, with specific reference to diagnosis and management of acute generalized exanthematous pustulosis (AGEP), drug reaction with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN). Here, we review recent guidelines on optimal supportive care as well as publications of interventional treatment for SJS/TEN, including various immunomodulating therapies, and management strategies for severe ocular disease with the use of amniotic membrane transplantation. In DRESS, long-term autoimmune sequelae are increasingly recognized and modify strategies for treatment of the acute episode. If the causative drug is not apparent from careful inspection of the drug exposure history, in-vitro diagnostics, HLA testing and skin testing before drug challenge testing may be considered and we present an algorithm for investigation of complex cases. Careful phenotypic analysis of the increasingly complex recognized patterns of SCAR facilitates the enhancement in our understanding of T-cell mediated drug hypersensitivity and allows the improvement of in-vitro diagnostic testing to minimize patient exposure to test substances in all but a very limited number of cases, thereby enhancing safety.