Forming diagnostic criteria for vulvar lichen planus

Vulvar lichen planus is a debilitating skin condition usually complicated by delayed diagnosis due to its highly variable clinical appearance and inconsistent histopathological characteristics. This study aims to devise a clinical diagnostic tool for the disease and to correlate this with histopathology findings.

The retrospective single-centre chart review was conducted for patients presenting between January 2010 and December 2019. Clinical features were compared between 243 women with clinically suspected vulvar lichen planus with available histopathology, 50 patients with biopsy-proven vulvar lichen sclerosus and 50 patients with culture-proven chronic vulvovaginal candidiasis. Features which significantly differentiated between conditions were further studied using multivariate nonlinear regression analyses to formulate a score-based diagnostic criteria. Criteria was then applied to the remaining patients with inconclusive biopsies (classified as 'normal', 'non-specific' or 'suggestive or lichenoid') to determine sensitivity and specificity.

The clinical features that significantly differentiated the conditions were the presence of erosions (P < 0.001), glazed erythema (P < 0.001), oral involvement (P < 0.001), pain/burning sensation (P < 0.001) and hyperkeratotic border (P < 0.001). A score ≥2 correlated with a histopathological diagnosis of vulvar lichen planus with a sensitivity of 100%. The specificity was 92% and 88% when compared against vulvar lichen sclerosus and chronic vulvovaginal candidiasis, respectively. Sensitivity was 97%, 97% and 93% in suggestive, nonspecific and normal histopathological subgroups, respectively.

The proposed criteria may aid clinicians in diagnosing patients if histopathology is inconclusive. Nonspecific and suggestive findings on biopsy for patients with ≥2 features on diagnostic criteria are comparable to a conclusive biopsy.