Fatal allopurinol hypersensitivity syndrome after treatment of asymptomatic hyperuricaemia

Allopurinol, an analogue of hypoxanthine, which inhibits xanthine oxidase, is an effective urate lowering drug that has been the cornerstone in the treatment of hyperuricaemia and gout for decades. In most patients, the drug is well tolerated, however, about 2% of treated patients develop a skin rash. Also, an estimated 0.4%, particularly people with kidney failure or having concomitant thiazide diuretic therapy, may experience a severe idiosyncratic reaction, known as allopurinol hypersensitivity syndrome. ] Most are asymptomatic and will never develop gout. Also, high urate concentrations do not seem to cause cardiovascular disease, as was previously thought. Consequently, urate lowering agents are not indicated in the treatment of asymptomatic hyperuricaemia. 4 5 We report a case of fatal allopurinol hypersensitivity syndrome after inappropriate treatment of asymptomatic hyperuricaemia.