Table 2.

Etiologic factors involved in uremic pruritus (11–15)

Electrolyte Abnormalities	Endocrine Disorders	Neurocutaneous	Other
Hypervitaminosis A	Secondary hyperparathyroidism	Abnormal signaling within cutaneous C nerve fibers	Xerosis (dry skin)
Hypercalcemia		Peripheral neuropathy	Elevated levels of inflammatory cytokines IL-2 and -6
Hyperphosphatemia		Increased serum β-endorphin, a μ-receptor agonist, in hemodialysis patients	Iron deficiency anemia
Hypermagnesemia		Substance P	↑ Amounts of dermal mast cells and histamine
			↑ Serum C-reactive protein
			↑ γ-Aminobutyric acid