A case of sulphasalazine-induced DRESS syndrome with delayed acute interstitial nephritis.

Drug rash with eosinophilia and systemic symptoms (DRESS syndrome) is a rare and severe drug-induced hypersensitivity syndrome characterized by haematological abnormalities (hypereosinophilia and/or mononucleosis) and multiorgan involvement. Renal failure has been rarely described. We report the case of a 77-year-old female with sulphasalazine-induced DRESS syndrome who improved rapidly on corticosteroid treatment. After prednisone withdrawal, the patient developed renal failure that necessitated a session of haemodialysis. A kidney biopsy showed acute tubulointerstitial nephritis with an intense lymphocytic infiltrate and tubular necrosis. Kidney function normalized after a further 2 weeks of corticosteroid treatment. This is the first histologically proven case of acute tubulointerstitial nephritis in the setting of sulphasalazine-induced DRESS syndrome.