Uremic frost

Abstract

Uremic frost is the white crystalline material found on the skin in the setting of severe azotemia. When blood urea nitrogen (BUN) levels rise, the level of urea in the sweat also rises. When sweat with significantly higher levels of urea evaporates, the urea crystallizes and is deposited on the skin as “uremic frost.” Typically seen with BUN levels?>?200, uremic frost was a common dermatologic finding in the pre-dialysis era. Today, however, it is rarely observed. Typically, if found at all today, uremic frost is seen in underdeveloped countries or in patients non-compliant with dialysis. It is generally a clinical diagnosis, but can be confirmed by testing the urea levels of the crystals diluted in a saline solution. The treatment is dialysis and the prognosis is grave, as its presence signifies severe azotemia.