Efficacy of topical hyaluronic acid for symptomatic oral lichen planus: A systematic Review

Background: Oral lichen planus (OLP) is a chronic inflammatory disorder with a potential of malignant transformation. Despite the extensive research on the topic, the management of OLP is still quite challenging, with no definitive cure. Objective: The present systematic review assessed the efficacy of topical hyaluronic acid in the management of OLP. Material and Methods: A comprehensive search of PubMed, Scopus, Web of Science and Google Scholar was carried out by two independent investigators. All randomized clinical trials that compared the efficacy of hyaluronic acid with other interventions and/or placebo in the management of OLP and fulfilled the following criteria were included: 1) OLP diagnosis was confirmed clinically and histopathologically, 2) the study included systemically healthy patients aged 15 years and older, 3) a minimum sample size of 10, and 4) reporting the main outcomes including pain, erythema, and ulcer size. Case reports, case series, reviews, animal studies, uncontrolled trials were excluded. Results: Four clinical trials involving 234 patients were included. Two studies compared hyaluronic acid with a topical corticosteroid, and two studies compared it with placebo. Only one of the four included studies was at low risk of bias. Overall, topical hyaluronic acid showed good efficacy in alleviating the signs and symptoms of OLP. Two studies found hyaluronic acid significantly more effective in reducing pain and improving clinical signs of OLP compared to placebo. Compared to topical corticosteroids, one study reported comparable results; and one study found hyaluronic acid to be superior to triamcinolone in reducing pain but inferior to triamcinolone in improving the healing time. Conclusion: The limited available evidence suggests that hyaluronic acid may have some benefits in the management of OLP. Further well-designed studies with adequate follow-up periods are highly recommended.