Expert opinion on characteristics of vulval LS: initial identification of important clinical features through an international electronic-Delphi consensus study.

Background: Lichen sclerosus (LS) is a chronic inflammatory condition mainly affecting genital skin. It causes distressing symptoms that impact daily quality of life as well as progressive anatomical changes and potential risk of cancer. Vulval LS is often misdiagnosed and treatment delayed. If non-experts are supported to identify clinical features of LS, they may diagnose the condition sooner and commence timely treatment or refer to specialist services for assessment and confirmatory biopsy.

Objectives: To reach international expert consensus on clinical diagnostic features for vulval LS.

Methods: Between March and May 2023, a four-stage electronic-Delphi consensus exercise was conducted. In the first three rounds, participants were asked to rate the importance of a list of clinical features. Responses from round one were summarised and presented in rounds two and three, along with additional features suggested by participants. Any items which met the definition of consensus as 'very important/critical', or 'not important' were not voted upon again in subsequent rounds. In round four, items which met agreement for 'important but not critical' were ranked in order of their importance. Consensus was defined a priori, and all rounds were conducted anonymously.

Results: A total of 47 participants from 14 countries completed round one with 42 (89%) retained by round 3 when consensus was determined. Round four was completed by 36 (77%) participants. Participants completing all four rounds predominantly included healthcare professionals (78%, n=28) and patient support group representatives (19%, n=7). In round one, 21 diagnostic features were voted upon. Participants suggested an additional 10 features which were subsequently added to the round two survey. After three rounds, consensus was achieved for five diagnostic features: whiteness, itch, changes in anatomy, burying of the clitoral area, and improvement in response to topical steroids. There were also 12 features voted as 'important but not critical' and participants subsequently ranked them in the 4th round.

Conclusions: Experts have agreed on five critical diagnostic features for vulval LS in adults and an additional 12 features that may also be important. Future research should assess these clinical features for diagnostic validity through a multicentre diagnostic test accuracy study.