Significant efficacy of short-course, low-concentration betamethasone mouthwash therapy for severe erosive oral lichen planus: a randomized controlled trial

OBJECTIVES: To evaluate the short-term efficacy of low-concentration betamethasone mouthwash for severe erosive oral lichen planus (EOLP). MATERIALS AND METHOD: In this randomized, investigator-blind, positive-controlled trial, OLP patients with erosive lesions received betamethasone mouthwash (0.137 mg/mL) or dexamethasone mouthwash (0.181 mg/mL) three times daily for 2 or 4 weeks and were followed up for 3 months to observe recurrence. The primary outcome was the week-2 reduction in erosive area. RESULTS: Fifty-seven participants were randomized to betamethasone (n = 29) and dexamethasone (n = 28). At week 2, participants using betamethasone (n = 28) experienced a greater reduction in erosive area than gargling with dexamethasone (n = 26). Similarly, secondary outcomes, including the healing proportion of erosions, reduced pain level, reduction in atrophic area, Thongprasom score, and recurrence interval, showed the superiority of betamethasone. At week 4, betamethasone (n = 7) was not superior to dexamethasone (n = 15) in further reducing lesional area and pain level. No serious adverse events were documented. CONCLUSIONS: The 0.137 mg/mL compound betamethasone mouthwash exhibited significant efficacy in rapidly enhancing erosion healing within 2 weeks and extending the recurrence interval with a good safety profile. CLINICAL RELEVANCE: This study proved the significant efficacy of short-course 0.137 mg/mL betamethasone mouthwash therapy for treating erosion and pain, providing a novel topical agent for patients with severe EOLP. TRIAL REGISTRATION: This study was prospectively registered at the International Clinical Trials Registry Platform (ChiCTR1800016507) on 5 June 2018. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00784-023-05051-w.