What is the initial management for itching that starts during peritoneal dialysis?

Initial Management of Itching in Peritoneal Dialysis Patients

Start with optimizing dialysis adequacy (target Kt/V ~1.6), normalizing calcium-phosphate balance, controlling parathyroid hormone levels, correcting anemia with erythropoietin, and applying emollients regularly—this stepwise approach forms the foundation before considering any pharmacologic interventions. 1

First-Line Management: Optimize Dialysis Parameters

Ensure Adequate Dialysis

• Increase dialysis dose to achieve a target Kt/V of approximately 1.6, as pruritus is significantly more common in underdialyzed patients and symptoms often improve with better dialysis adequacy 1, 2
• Studies demonstrate that improved dialysis techniques consistently reduce the prevalence of itching in end-stage renal disease patients 2

Correct Metabolic Abnormalities

• Normalize calcium-phosphate balance to accepted levels, as divalent-ion abnormalities contribute to uremic pruritus 1, 3
• Control parathyroid hormone levels, since secondary and tertiary hyperparathyroidism frequently accompany end-stage renal disease and may contribute to pruritus 1, 3
• Correct anemia with erythropoietin if present, as iron-deficiency anemia has been implicated in the pathophysiology of uremic pruritus 1, 4

Address Xerosis (Dry Skin)

• Apply emollients regularly (preferably twice daily), as xerosis is the most common cutaneous sign in dialysis patients and lowers the threshold for itch 1, 5
• An aqueous gel containing high water content (80%) applied twice daily significantly reduces itching and improves xerosis in patients with mild uremic pruritus 5

Second-Line Treatment: Topical Therapy

Topical Capsaicin

• Apply capsaicin 0.025% cream to affected areas four times daily, which has demonstrated significant efficacy with 14 of 17 patients reporting marked relief and 5 achieving complete remission in randomized trials 1
• Capsaicin works by depleting neuropeptides including substance P in peripheral sensory neurons 1

Phototherapy

• Consider broad-band UVB (BB-UVB) phototherapy if topical treatments provide insufficient relief after 2-4 weeks of consistent use, as this has strong evidence supporting its effectiveness for uremic pruritus 1

Third-Line Treatment: Systemic Therapy

Gabapentin (Most Effective Medication)

• Administer gabapentin 100-300 mg after each dialysis session (three times weekly) if first and second-line measures fail 1
• These doses are significantly lower than those used in non-ESRD populations due to reduced renal clearance 1
• Common side effects include mild drowsiness 1

Important Pitfalls to Avoid

Ineffective Treatments

• Do NOT use cetirizine, as it has been specifically shown to be ineffective for uremic pruritus despite efficacy in other pruritic conditions 1, 6
• Avoid calamine lotion and crotamiton cream, as there is no literature supporting their use and crotamiton has been shown ineffective compared to vehicle control 1
• Avoid long-term sedative antihistamines (diphenhydramine, hydroxyzine) except in palliative care settings, as they may predispose to dementia 1, 6

Treatment Limitations

• Limit topical doxepin to 8 days maximum, 10% of body surface area, and 12 g daily if used for severe cases 1
• Non-sedative antihistamines (fexofenadine 180 mg, loratadine 10 mg) may be tried but have limited evidence for efficacy specifically in uremic pruritus 1

Clinical Context

Pruritus affects 42-60% of peritoneal dialysis patients, typically beginning about 6 months after dialysis initiation 7, 3. The condition can be generalized (50% of cases) or localized (commonly affecting the back, face, or arteriovenous fistula arm), with intensity ranging from mild intermittent irritation to intractable itch that severely disrupts sleep and quality of life 1, 7. Symptoms often worsen during summer months or at night 1, 7.