Pruritus in Chronic Kidney Disease

Nupur N. Uppal; Antonio Corona; Steven Fishbane


Curr Opin Nephrol Hypertens. 2022;31(5):435-441. 

In This Article

Pathobiology of Pruritus in Kidney Disease

Although the exact reason that itch exists is not fully known, it is likely that similar to pain, it serves to ward off noxious environmental stimuli. Pain may signal more severe disruptions and itch lighter and more difficult to discern stimuli, like an arthropod crawling on the skin surface. A stimulus on/in the skin is detected by free nerve endings and transmitted to the dorsum (posterior section) of the spinal cord, where the signal continues to the brain for contextual processing. The nerve stimulation in the skin, or the resulting scratch, leads to the release of substances like histamine and cytokines which is important in that it connects the nervous and immune systems.

The pathogenesis of CKD-aP is incompletely understood. The current understanding is that, like all itching, it is a spectrum that ranges from itch being a normal, physiologic response, while at the other end of the spectrum lies pathologic itching. The latter refers to the perception of itchiness being present without a corresponding pruritogenic stimulus. For CKD-aP specifically, an array of factors has been hypothesized to be responsible for its pathogenesis. In the paragraphs that follow, we will briefly explore some of these contributing factors.