No good treatments available
According to our findings purslane is clinically effective in the treatment of oral lichen planus. Considering the lack of side-effects during the study period, it may be a favorable alternative treatment for OLP.
https://pubmed.ncbi.nlm.nih.gov/19585472/
http://www.oralmedicinelondon.co.uk/conditions-treated/oral-medicine/lichen-planus/