Interventions for chronic pruritus of unknown origin.

Area of Science:

• Dermatology
• Clinical Trials
• Evidence Synthesis

Background:

• Chronic pruritus of unknown origin (CPUO) affects 8-15% of patients with pruritus, with higher prevalence in the elderly.
• Pathophysiology of CPUO is poorly understood, making treatment challenging.
• Effective management of pruritus relies on identifying and treating the underlying cause, which is not possible in CPUO.

Purpose of the Study:

• To assess the efficacy and safety of interventions for chronic pruritus of unknown origin (CPUO) in adults and children.
• To identify evidence-based treatments for CPUO.
• To evaluate outcomes such as pruritus intensity, adverse events, quality of life, and sleep disturbances.

Main Methods:

• Systematic review of randomized controlled trials (RCTs) and quasi-RCTs.
• Searched multiple databases including Cochrane Skin Group, CENTRAL, MEDLINE, and Embase up to July 2019.
• Included studies assessing interventions for CPUO (IFSI classification category VI) in adults and children, comparing them against placebo, sham procedures, or no treatment.

Main Results:

• A significant lack of evidence was found for common interventions like emollients, corticosteroids, and antihistamines.
• One study on serlopitant (a neurokinin 1 receptor antagonist) was included, involving 257 participants.
• Low-certainty evidence suggests serlopitant 5 mg may reduce pruritus intensity compared to placebo; effects on other outcomes and lower doses are uncertain due to very low-certainty evidence and indirectness.

Conclusions:

• There is a substantial lack of evidence for effective treatments for chronic pruritus of unknown origin (CPUO).
• Serlopitant showed potential for reducing pruritus intensity, but the evidence is of low certainty.
• Further high-quality studies with larger sample sizes focusing specifically on CPUO patients are required to guide clinical practice.