Effects of Psychological Interventions on Itch, Scratching, and Excoriations: A Systematic Review and Meta-analysis.

Psychological interventions reduce itch in patients with skin diseases. However, previous systematic reviews and meta-analyses did not include patients with non-skin-related chronic itch and did not consider excoriations as outcome. This study therefore summarized randomized controlled trials investigating effects of psychological interventions on itch, scratching, and excoriations in patients with chronic itch due to all causes. A systematic literature search was conducted. A random effects model was used to aggregate between-group effect sizes. It was found that 17 of the 20 trials included patients with atopic dermatitis. Small to large post-treatment and follow-up effects were observed on self-rated itch intensity (post-treatment: k = 12, g = -0.37 [-0.60; -0.15]; follow-up: k = 6; g = -0.59 [-0.97; -0.21]), externally rated excoriations (post-treatment: k = 6, g = -0.29 [-0.49; -0.09]; follow-up: k = 6; g = -0.34 [-0.53; -0.15]), and self-rated scratching intensity (post-treatment: k = 2, g = -0.99 [-1.35; -0.63]; follow-up: k = 2; g = -0.85 [-1.22; -0.48]). Small post-treatment effects were observed on self-rated itch frequency (k = 3, g = -0.22 [-0.40; -0.04]). Thus, psychological interventions show promise in reducing not only itch and scratching, but also excoriations, with effects lasting up to 1 year.