DRESS syndrome caused by efalizumab.

We report a case of drug reaction with eosinophilia and systemic symptoms (DRESS) to efalizumab. A 52-year-old man developed a widespread papulovesicular rash after 4 weeks of treatment with efalizumab (1.0 mg/kg/week) for treatment-resistant severe psoriasis. Histology revealed a subepidermal blister with eosinophil-rich inflammatory cell infiltrate. Subsequently, the patient developed high peripheral eosinophilia, abnormal liver function, malaise and fever, all requiring inpatient admission. Efalizumab was discontinued immediately, but the rash persisted for 4 months and was only controlled by oral prednisolone at a dose of 30 mg/day. To our knowledge, this is the first reported case of DRESS caused by efalizumab.