uremic frost
Crystalline deposits of urea on the skin surface, appearing as a white powdery coating in patients with severe uremia.
Full Definition
Uremic frost is a rare but pathognomonic sign of severe uremia, manifesting as white, crystalline deposits of urea that accumulate on the skin surface, particularly on the face, scalp, and areas of high sweat production. This finding indicates extremely elevated blood urea nitrogen levels, typically exceeding 200-300 mg/dL, and represents a medical emergency requiring immediate dialysis. In pediatric nephrology, uremic frost is uncommon due to earlier recognition and treatment of chronic kidney disease, but when present, it signifies life-threatening uremic toxicity. The crystals form when urea is excreted through sweat glands and crystallizes as the sweat evaporates. Other severe uremic signs often accompany this finding, including altered mental status, pericarditis, and bleeding tendency.
Usage
Usage note: This is a rare finding in modern pediatric practice due to earlier intervention; indicates urgent need for dialysis.
In Context
- "The patient presented with uremic frost and altered mental status, indicating severe uremic toxicity." — Emergency department assessment
- "Uremic frost was noted on the forehead and scalp with blood urea nitrogen of 280 mg/dL." — Critical care consultation