*2.7.2 Pruritis*

It is a common and troubling symptom of itching, which patients experience during and after haemodialysis, the symptom of which cannot be attributed to other causes [18].

It has a prevalence of 22–48% in haemodialysis patients.

Cause is often multifactorial and includes: xerosis, hyperparathyroidism, neuropathy, immune dysregulation and inadequate dialysis.

The two major hypotheses of pathogenesis of uremic pruritis include:


Other proposed theories include toxin deposition, based on observation that pruritis was associated with underdialysis and CKD-MBD.

Treatment involves:

a.Optimising dialysis: Achieving dialysis adequacy of Kt/V of >1.2 has been associated with reduced incidence of itching.

Expanded haemodialysis is a new concept in haemodialysis with medium cut-off membrane, which increases the clearance of middle and large molecules without significant albumin loss, compared to conventional haemodialysis, which clears only small molecules. This might help patients with severe pruritic symptoms and other complications of CKD (**Table 3**) [19].


#### **Table 3.**

*Various sizes of uremic toxins and their clinical effect.*

	- a.Skin emollients.
	- b.Antihistamines like montelukast or cetirizine.
	- c.Phototherapy: UV B (wavelength 280–315 nm) is effective in treatment of pruritis.
	- d.Opioid receptor agonist: nalfurafine given iv after HD improved patient experience.
	- e.Nalfurafine is an orally active kappa opioid receptor agonist which has shown benefit in treatment of uremic pruritis.
	- f. Gabapentin: given 300 mg after HD was effective in reducing pruritis.
	- g.Other therapies include capsaicin, long-chain fatty acids and immunosuppressants.
