DRESS Syndrome

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a potentially life-threatening drug hypersensitivity reaction that occurs 2-8 weeks after exposure.  Characteristic clinical findings include a diffuse, erythematous skin rash, fever, facial swelling, lymphadenopathy, eosinophilia, and visceral organ dysfunction.  The diagnosis is largely clinical; treatment involves the immediate cessation of the inciting drug and supportive care (eg, fluids).  Most patients recover completely within weeks or months, but relapses may occur.

DRESS syndrome is a delayed T cell–mediated hypersensitivity reaction commonly associated with medications such as antiepileptics (eg, phenytoin), antibiotics (eg, minocycline), and allopurinol.  Unlike other drug reactions, DRESS syndrome has an unusually long latency (2-8 weeks) between drug initiation and the manifestation of symptoms.

The exact pathogenesis is unclear but likely involves a combination of metabolic, genetic, and immunologic factors that cause activation of drug-specific T lymphocytes.  These activated T cells release proinflammatory cytokines (eg, tumor necrosis factor alpha), which trigger a robust immune response that leads to inflammation, tissue injury, and necrosis across multiple organ systems, including the skin, liver, kidneys, lungs, and heart.