Effectiveness of hyaluronic acid in the management of oral lichen planus: a systematic review and meta-analysis

Oral lichen planus (OLP) is a chronic inflammatory immune-mediated condition that has been identified as a potentially malignant oral disorder. Various therapies have been proposed for its management as alternative to corticosteroids. However, no definitive treatment has been identified that can result in complete remission or minimal recurrence. Hyaluronic acid has recently been used as an alternative therapy for the management of OLP. This study aimed to systematically review the effectiveness of Hyaluronic acid in the management of symptomatic OLP. Online electronic databases and manual searches were performed for randomized controlled trials (RCTs) published in English between January 2010 and April 2022. RCTs were identified that compared the efficacy of hyaluronic acid and other interventional therapies at baseline and during follow-up. The Cochrane Risk of Bias tool was used to assess the quality of the included studies. Visual analog scale (VAS) scores, Thongprasom sign scores, lesion size, degree of erythema, clinical severity, and disease severity were assessed both quantitatively and qualitatively. Seven studies were analyzed. Five studies reported a high risk of bias while the remaining two studies reported an unclear risk of bias. The overall quantitative assessment of size, symptoms, degree of erythema, and sign score in OLP lesions treated with HA was not statistically significant compared to that in the control group (P > 0.05). In addition, subgroup analysis comparing HA with placebo or corticosteroids did not yield statistically significant (P > 0.05) results. Qualitatively, both HA and tacrolimus resulted in an effective reduction in signs and symptoms. Clinical/disease severity index/scores were inconsistent. A high degree of heterogeneity was observed among the included studies. None of the included studies reported the side effects of HA. These findings suggest that corticosteroids, tacrolimus, placebo, and HA could be equally effective in OLP management. The clinical/disease severity index or score reduction cannot be determined with certainty. Thus, OLP can be treated with HA as an alternative therapy. Owing to limited clinical trials on HA, high heterogeneity, and high risk of bias in the included studies, definitive conclusions cannot be derived.