Please tell me what can i do to help to clear up the dark spots from lichen planus?

See a dermatologist: The post-inflammatory darkening that can happen after lichen planus lesions heal can be a problem. Sometimes the strong topical steroids we use to treat LP helps also with the darkening. Hydroquinone is also useful in lightening these spots. Foremost, it is important that you are being treated for LP to minimize the chances you will get new dark spots. See your dermatologist to discuss options.