I have had lichen planus since late 90's. is it normal to have it so long? still get painful sores on tongue.should i see dermatology or oral surgeon?

Can happen: This varies from individual to individual. Both severity and duration varies. Some patients continue to have lichen planus for the rest of their lives. I would consult with either an oral surgeon or an oral pathologist. There are medications that may be helpful, especially in the acute phases.

Normal: Lichen planus is one of those maladies that tends to stay with us once it is acquired. It tends to display as both skin lesions and oral lesions...So, it is dealt with by professionals in both specialties. A dermatologist or a dental professional trained in oral medicine or oral biology can give more information regarding treatment.

Dermatologist: Lichen planus in the oral cavity has several causes that can be treated. You should see a dermatologist who can perform additional tests eg. Patch testing if indicated to find the cause if possible.

I would recommend: dermatologist, unless it is an oral surgeon who is experienced with lichen plans