A Narrative Review of Placebo and Nocebo Effects on Itch

Abstract

There is limited information available on the evaluation of placebo or nocebo effects on itch. The present study developed a search strategy using PubMed to evaluate literature related to placebo and/or nocebo effects on itch. The search strategy identified 65 articles. After the independent review of each article, 10 studies were selected for inclusion. These studies varied, in terms of methods and outcome measures. Overall, verbal suggestion, conditioning, and/or placebo topical therapies led to placebo and/or nocebo effects on itch. Further understanding the mechanisms of placebo and nocebo effects on verbal suggestion and conditioning can open doors to the development of therapeutic strategies that could ameliorate or improve itch in patients.