31891 Oral metronidazole use in mucosal lichen planus

Abstract

Lichen planus (LP) is estimated to impact 0.2-1% of the adult population. The mucosal variants, including oral, esophageal, and vulvovaginal forms have remitting chronic courses that negatively impact quality of life. Mucosal variants are more challenging to treat than cutaneous LP due to lower likelihood of spontaneous regression. Metronidazole, an antibiotic for anaerobic or protozoal infections, has been reported as an effective treatment and, in some cases, causes remission of cutaneous LP, when patients were treated for a concomitant infection. Following IRB approval, we reviewed patients at our institution over the last 10 years with a diagnosis of LP using international classification of disease (ICD) codes. We collected demographics, treatment methods, disease course, diagnosis, adverse effects, and comorbidities. While 956 charts were reviewed, only 558 of these had LP and 273 qualified as mucosal LP. Fifty-three patients with mucosal LP were treated with oral metronidazole. Six patients (11.3%) reported complete resolution at their first follow-up, while 25 patients reported partial improvement at their first follow-up (47.2%). Twenty-two patients (41.5%) had no improvement with metronidazole even after their second follow-up visit. Discontinuation of metronidazole was most often due to insufficient response (n = 27, 50.9%), with only 13 patients (24.5%) experiencing adverse effects, 61.5 % of which were gastrointestinal in nature. Due to the relatively mild side effect profile compared with alternative treatment options, metronidazole is reasonable to try in patients with mucosal LP.