DRESS syndrome (drug rash, eosinophilia and systemic symptoms) is an idiosyncratic drug reaction characterised by rash, fever, lymphadenopathy and internal organ involvement. The authors report a case of this syndrome presenting with fever, generalised pruritus, macular rash and cholestatic hepatitis during allopurinol treatment. This case resolved with drug withdrawal, but the death rate in the setting of hepatic failure can reach 10%. Rapid diagnosis is crucial as prompt withdrawal of the offending drug is the key of the treatment, while the potential role of corticosteroids remains controversial.