[4] The autoimmune reaction most commonly affects the oral mucosa in the mouth, causing lesions in the gums (gingiva), known as desquamative gingivitis.

When the condition is active, the basement membrane is dissolved by the antibodies produced, and areas of skin lift away at the base, causing hard blisters which scar if they burst.

In other words, this is a desquamating/blistering disease in which the epithelium "unzips" from the underlying connective tissue, allowing fluid to gather that subsequently manifest as bullae, or blisters.

Many other drugs have been used to treat mucous membrane pemphoid, including azathioprine, cyclophosphamide, methotrexate, thalidomide, mycophenolate mofetil, leflunomide, sulphasalazine, sulphapuridine, sulphamethoxypiridazine, tetracyclines (e.g. minocycline, doxycycline) and nicotinamide.

Sometimes surgical procedures are required to repair scars, prevent complications such as blindness, upper airway stenosis or esophageal stricture.