Interventions for chronic pruritus of unknown origin

• Published in: Cochrane database of systematic reviews 2020-01, Vol.1 (1), p.CD013128
• Main Authors: Andrade, Andrea, Kuah, Chii Yang, Martin-Lopez, Juliana Esther, Chua, Shunjie, Shpadaruk, Volha, Sanclemente, Gloria, Franco, Juan Va
• Format: Article
• Language: English
• Subjects: Aging - pathology; Child health; Emollients - therapeutic use; Humans; Mental health; P. PSYCHOLOGICAL, PSYCHIATRIC AND RELATED DISORDERS OF THE SKIN; Phototherapy; Pruritus - drug therapy; Pruritus - etiology; Pruritus - therapy; Quality of Life; Randomized Controlled Trials as Topic; Severity of Illness Index; Skin Care - methods; Skin Cream - therapeutic use; Skin disorders; Treatment Outcome
• ISSN: 1469-493X; 1469-493X
• DOI: 10.1002/14651858.CD013128.pub2

Pruritus is a sensation that leads to the desire to scratch; its origin is unknown in 8% to 15% of affected patients. The prevalence of chronic pruritus of unknown origin (CPUO) in individuals with generalised pruritus ranges from 3.6% to 44.5%, with highest prevalence among the elderly. When the origin of pruritus is known, its management may be straightforward if an effective treatment for the causal disease is available. Treatment of CPUO is particularly difficult due to its unknown pathophysiology. To assess the effects of interventions for CPUO in adults and children. We searched the following up to July 2019: Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, and trials registries. We checked the reference lists of included studies for additional references to relevant trials. We sought to include randomised controlled trials and quasi-randomised controlled trials that assessed interventions for CPUO, as defined in category VI ('Other pruritus of undetermined origin, or chronic pruritus of unknown origin') of the International Forum for the Study of Itch (IFSI) classification, in children and adults. Eligible interventions were non-pharmacological or topical or systemic pharmacological interventions, and eligible comparators were another active treatment, placebo, sham procedures, or no treatment or equivalent (e.g. waiting list). We used standard methodological procedures expected by Cochrane. Our primary outcomes were 'Patient- or parent-reported pruritus intensity' and 'Adverse events'. Our secondary outcomes were 'Health-related quality of life', 'Sleep disturbances', 'Depression', and 'Patient satisfaction'. We used GRADE to assess the certainty of evidence. We found there was an absence of evidence for the main interventions of interest: emollient creams, cooling lotions, topical corticosteroids, topical antidepressants, systemic antihistamines, systemic antidepressants, systemic anticonvulsants, and phototherapy. We included one study with 257 randomised (253 analysed) participants, aged 18 to 65 years; 60.6% were female. This study investigated the safety and efficacy of three different doses of oral serlopitant (5 mg, 1 mg, and 0.25 mg, once daily for six weeks) compared to placebo for severe chronic pruritus; 25 US centres participated (clinical research centres and universities). All outcomes were measured at the end of treatment (six weeks from baseline), except adverse events, which were monitored throughout. A pharmaceu