The authors would like to publish an erratum to the above article.

The Discussion section of the original publication previously said:

Furthermore, PSAAD was developed to meet regulatory guidance and—unlike POEM, Itch Numeric Rating Scale (v2.0), Skin Pain Numeric Rating Scale (v2.0b), and Peak Pruritus Numerical Rating Scale—to be included in product-labelling claims in the USA and Europe.

However, these instruments, including the Peak Pruritus Numerical Rating Scale, have either accumulated sufficient evidence to meet regulatory guidance related to product-labelling claims and/or have since been recommended for use in clinical trials. Accordingly, the specific references to these instruments should be deleted, and the sentence should read as follows:

Furthermore, PSAAD was developed to meet regulatory guidance and to be included in product-labelling claims in the USA and Europe.

The original article has been corrected.