Suggest Treatment For Scalp Psoriasis

My son has been suffering with scalp psoriasis for over 10 yrs. no treatments have helped, he is now bald except for his hairline all the way around the perimeter of his head. I would like to know if there are any treatments that will begin to regrow is head. he is 18 yrs old & insecure as a result of suffering through his school years being teased & ostrasized