Bullous pemphigoid is an autoimmune disorder that occurs when the immune system attacks the skin and causes blistering.
People develop large, itchy blisters with areas of inflamed skin.
Doctors can diagnose bullous pemphigoid by examining skin samples under a microscope and checking for certain antibody deposits.
Treatment involves corticosteroids and drugs that suppress the immune system.
(See also Overview of Blistering Disorders.)
Bullous pemphigoid occurs more often in people over age 60 but can occur in children. It is a less serious disease than pemphigus vulgaris (which also causes blistering), is not usually fatal, and does not result in widespread peeling of skin. It can involve a large portion of the skin, however, and can be very uncomfortable.
Although the cause of bullous pemphigoid is unknown, drugs (such as furosemide, spironolactone, sulfasalazine, antipsychotic drugs, penicillin, penicillamine, and etanercept), physical causes (such as radiation therapy for breast cancer and ultraviolet radiation), skin disorders (such as psoriasis, lichen planus, and some infections), and certain other disorders (such as diabetes, rheumatoid arthritis, ulcerative colitis, and multiple sclerosis) may be triggers.
Itching is often the first symptom of bullous pemphigoid. Before blisters appear, large, raised areas may develop, sometimes looking like hives. The immune system eventually forms antibodies directed against the skin, resulting in large, tense, and very itchy blisters surrounded by areas of normal-appearing skin or red, inflamed skin. Blisters commonly develop on the parts of the body that are able to flex, such as the backs of the knees, the underarms, the insides of the elbows, and the groin. Blisters in the mouth are rare.
Doctors usually recognize bullous pemphigoid by its characteristic blisters. However, it is not always easy to distinguish it from pemphigus vulgaris and other blistering conditions, such as severe poison ivy. Bullous pemphigoid is diagnosed with certainty by examining a sample of skin under a microscope (skin biopsy). Doctors differentiate bullous pemphigoid from pemphigus vulgaris by noting the layers of skin involved and the particular appearance of antibody deposits.
Initially, doctors give people potent corticosteroid creams, such as clobetasol, to apply directly to the skin. These creams may reduce the need for drugs taken by mouth. People who have blisters on large portions of skin often need the corticosteroid prednisone taken by mouth, which is gradually reduced (tapered) after several weeks. Most people are symptom-free after 2 to 10 months.
The combination of nicotinamide and either minocycline or tetracycline is sometimes successful in treating bullous pemphigoid. Other drug options include treatment with only dapsone, sulfapyridine, or erythromycin. Sometimes, drugs that suppress the immune system, such as methotrexate, azathioprine, mycophenolate mofetil, rituximab, or cyclophosphamide, are given to people with severe disease that does not respond to other treatment. Immune globulin given by vein (intravenously) is used occasionally.
Although some skin care, such as keeping the affected areas clean to prevent infection and perhaps wearing loose-fitting clothes, may be needed, most people do not require hospitalization for intensive skin care treatment.