From the Guidelines
The rash associated with impaired renal function is called uremic frost. This condition occurs in advanced kidney failure when urea and other waste products that would normally be filtered by the kidneys accumulate in the body and are excreted through the skin 1. Uremic frost appears as a white, powdery deposit on the skin, often on the face, chest, and extremities. It's relatively rare today due to earlier intervention with dialysis in patients with kidney failure. The condition is a sign of severe uremia (high levels of urea in the blood) and indicates the need for immediate medical attention, typically dialysis.
Key Characteristics of Uremic Frost
- The mechanism involves nitrogenous waste products crystallizing on the skin surface after being excreted in sweat.
- Patients with uremic frost often experience intense itching (uremic pruritus) and may have yellowish skin discoloration (uremic complexion) as well.
- This manifestation represents a late-stage complication of kidney disease and requires prompt medical intervention. Some studies also report other oral and skin manifestations in patients with impaired renal function, such as lichenoid oral lesions, oral hairy leukoplakia, Kaposi’s sarcoma, and non-Hodgkin lymphoma, particularly in those undergoing immunosuppressive therapy 1. However, uremic frost is specifically associated with the accumulation of urea and other waste products in the skin due to kidney failure.
From the Research
Cutaneous Manifestations of Renal Disease
The rash associated with impaired renal function is known as uremic frost.
- Uremic frost is a striking cutaneous finding seen in patients with severe kidney disease 2.
- It is caused by an increased concentration of urea in the sweat, resulting in a white coating on the skin 3, 2.
- Uremic frost generally occurs at blood urea nitrogen levels of approximately 200 mg/dl, although it may arise with less severe uremia 2.
Prevalence of Uremic Frost
- Uremic frost is a rare manifestation of chronic renal failure, occurring in approximately 3% of patients on hemodialysis 4.
- It is often associated with other cutaneous manifestations, such as xerosis, pruritus, and cutaneous pigmentation 4.
- The treatment of uremic frost is largely aimed at correcting the underlying cause of uremia and the other life-threatening conditions associated with renal failure 2.
Other Cutaneous Manifestations
- Other cutaneous manifestations of renal disease include half-and-half nails, Kyrle's disease, and pseudo-Kaposi's sarcoma 3, 4.
- These manifestations can provide important clues to the diagnosis of renal disease and can help guide treatment 3.
- The early recognition of cutaneous signs can relieve suffering and decrease morbidity in patients with renal disease 4.