Uremic frost is a colloquial description for crystallized urea deposits that can be found on the skin of those affected by chronic kidney disease (CKD). Uremic frost was first described in 1865 by Harald Hirschsprung (1830-1916), a Danish pediatrician. He was also the first to describe Hirschsprung's disease in 1886. The disease now carries his name. Uremic frost has become increasingly uncommon with the advent of dialysis in the 1950s. Uremic frost is a classical pre-dialysis era description of crystallized urea deposits over the skin of patients with prolonged kidney failure and severe uremia. High blood urea level leads to high secretion of urea by sweat glands as a component of sweat. As water evaporates off the skin, it results in crystallization of the remaining urea which appear as white salts over the skin. This condition is more common in severe, untreated uremia and is associated with serum BUN levels >200. It is becoming rare in people with chronic kidney disease managed on long-term hemodialysis, with estimated prevalence between 0.8 and 3%.