The diagnosis is confirmed by taking a skin biopsy of a typical blister. Under the microscope, the pathologist can see a split between the main layers of the skin, the epidermis and the dermis. This is thought to occur because antibodies and white blood cells attack the membrane that holds the skin together. It can be thought of as a type of allergy to one's own skin, i.e. one of the autoimmune disorders. If the pemphigoid is widespread, hospital admission is usually arranged so the blisters and raw areas can be expertly dressed, and the effect of treatment assessed.
Infection also needs to be treated.
Bullous pemphigoid is treated with steroid tablets, usually prednisone. The dose is adjusted until the blisters have stopped appearing, which usually takes several weeks. The dose of prednisone is then slowly reduced over many months or years. As steroids have some undesirable side effects, we try to reduce the dose as low as possible. If this is done too quickly, the blisters reappear.