[Topical silver sulfadiazine-induced acute renal failure]

Prolonged topical application of silver sulfadiazine cream can induce argyria and adverse effects of sulphonamides. We report a case of a woman with acute renal failure following repeated applications of topical silver sulfadiazine on pyoderma gangrenosum wounds.

A 61 year-old woman suffering from rheumatoid arthritis, Sjogren's syndrome and scleroderma was treated with corticosteroids (1 mg/kg/day) and topical application of silver sulfadiazine cream (200 g/day) for extensive pyoderma gangrenosum wounds on the legs. Three weeks later, the patient was transferred to intensive care because of pulmonary edema, oligoanuria and disrupted consciousness. Laboratory data revealed leukopenia (1100/mm(3)) with neutropenia and renal failure (serum creatinine 316 micromol/l). Proteinuria was moderate and ultrasonography of the kidneys was normal. Silver concentration in blood was 1818 nmol/l (N < 92 nmol/l) and 1381 nmol/l (N < 9 nmol/l) in urine. Sulfadiazine concentration in blood was undetectable. All the signs regressed after withdrawal of silver sulfadiazine and after several sessions of hemodialysis.

Various causes of renal failure are discussed in our patient. However, direct silver-induced renal toxicity is the most likely and is confirmed by the high concentration of silver in blood and urine and the improvement on withdrawal of the topical cream, without modification in the oral treatment. The absence of red corpuscles and crystals in the urine and undetectable concentrations of sulfadiazine in blood are not in favor of sulphonamide renal toxicity. Furthermore, the autoimmune diseases of our patient were well-controlled. Leukopenia could be secondary to silver sulfadiazine medullar toxicity. This observation confirms that this topical cream should not be used for long periods on extensive wounds.