Hi doctors, can you tell me what is lichen planus and how is caused and what treatment is best for it?

Lichen Planus. Lichen planus will wax and wane. It is a chronic rash of unknown cause with no cure, may be itchy and poorly understood by medicine. It can be managed with medication both topical and oral. It may resolve on its own. Wish i could help more; see your dermatologist to manage this disease.