The drug hypersensitivity syndrome - What is the pathogenesis?

Drug hypersensitivity syndrome (DHS) is a severe idiosyncratic reaction ass ociated with drug therapy. Cutaneous eruptions are the most common idiosync ratic reaction to drugs, but DHS is not just a drug-related eruption. We de fined DHS by the clinical tried of fever, rash, and internal organ involvem ent.(1) The pathogenesis of this disease is not well defined; however, intr iguing clinical and laboratory observations and associations provide insigh t into the mechanistic puzzle of this iatrogenic disease. The article in th is issue by Descamps et al(2) raises further questions as to this syndrome' s association with viral infection. Understanding the pathomechanism of DHS is important for the prevention and improved management of these potential ly life-threatening reactions.