LAUSR

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare but severe drug hypersensitivity reaction presenting with skin eruption, fever, lymphadenopathy, eosinophilia and organ system involvement. The rash is typically morbilliform in nature and can become infiltrative and indurated with associated edema. Eosinophilia is noted in up to 90% of cases and some patients exhibit leukocytosis up to 50 000 cells/μL with prominent thrombocytopenia. The liver is the most commonly involved internal organ in DRESS syndrome and fulminant hepatic necrosis is a leading cause of death in these patients. The timing of this drug eruption is the hallmark of DRESS syndrome. In contrast to most other drug hypersensitivities, DRESS syndrome often presents 2 to 6 weeks after the initiation of an offending medication. The pathogenesis is not clearly elucidated, but possible mechanisms include deficient drug metabolism leading to build-up of toxic metabolites, immunologic over-activation resulting in recruitment of cytotoxic T-cells and eosinophils into tissues and reactivation of herpesvirus, particularly human herpesvirus-6 (HHV-6). A wide variety of medications have been associated with development of DRESS syndrome, most commonly implicated include aromatic anticonvulsants, sulfasalazine, dapsone, and minocycline. The treatment revolves around prompt removal of the offending medication, symptomatic support, and corticosteroids to mitigate internal organ damage.