Allopurinol sensitivity: Report of two cases

Abstract

Two cases of sensitivity to allopurinol are reported. Patient 1, a 72-year-old white man, developed a fever 11 days after beginning therapy with allopurinol 300 mg daily. He was admitted to the hospital 11 days later with nausea, vomiting, generaliczed weakness, a generalized maculopapular rash and ahnurnially elevated liver enzymes. On admission, allopurinol was discontinued and diphenhydramine hydrochloride, 100 mg daily, and cyproheptadine hydrochloride, 16 mg daily, were • started. Prednisone, 60 mg/day, was begun six days later with subsequent reduction in fever and liver enzyme levels. Daily' prednisone was reduced over the next 28 days to 20 mg, the dosage at discharge on day 37. Patient 2, a 53-year-old black man, developed a pruritic erythematous maculopapular rash, fever and general malaise four weeks after beginning treatment with allopurinol 200 mg daily. Allopurinol was discontinued immediately before admission to the hospital. Liver enzymes and white blood cell count were elevated. Four days after admission, the rash began to desquamate and the fever abated. The patient was discharged after 17 days. Skin and white blood cell count returned to normal within four weeks of discharge. The classic symptoms, clinical course and treatment of allopurinol sensitivity reactions are reviewed. Moderate and severe reactions seem to be more prevalent in patients with preexisting renal impairment. Allopurinol should be discontinued in any patient with a suspected sensitivity reaction accompanied by fever and skin rash. Patients whose symptoms do not improve or worsen probably require steroids.