Uremic frost

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) and uremia.^[1] It was first described in 1865 by Harald Hirschsprung (1830-1916), a Danish pediatrician.^[2]

Uremic frost on forehead and scalp

The condition arises when high blood urea levels lead 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.^[3] This condition is more common in severe, untreated uremia and is associated with serum blood urea nitrogen (BUN) levels above 200^{[clarification needed]}. It is becoming rare in people with chronic kidney disease managed on long-term hemodialysis, with estimated prevalence between 0.8 and 3%.^[4][5][6]