This is a group of autoimmune diseases characterized by blisters, sloughing, and ulceration of the gums. Only a special biopsy can determine which of these diseases you have. The treatment is topical steroids with or without oral medication. These diseases can be very painful and can also involve the skin or even the eyes, in which case blindness is possible if severe enough and left untreated. If you think that you may have something like that described above, see a periodontist for a proper diagnosis and treatment.