Pemphigus

Pemphigus (pemphigus vulgaris) is a rare, severe autoimmune disease in which blisters of varying sizes break out on the skin, the lining of the mouth, the genitals, and other mucous membranes.

Pemphigus develops most often in middle-aged or older people. It rarely develops in children. In this disease, the immune system produces antibodies that attack specific proteins that connect the epidermal cells (the cells in the top layer of skin) to each other. When these connections are disrupted, the cells separate from the lower layers of the skin, and blisters form. A similar-appearing but less dangerous disease, bullous pemphigoid, results in shallower blisters.

Symptoms

The major symptom of pemphigus is the development of clear, soft, painful blisters of various sizes. In addition, the top layer of skin may detach from the lower layers in response to slight pinching or rubbing, causing it to peel off in sheets.

The blisters that develop often first appear in the mouth and soon rupture, forming painful ulcers (sores). More blisters and ulcers may follow until the entire lining of the mouth is affected, causing difficulty swallowing. Blisters form on the skin as well. These blisters then rupture, leaving raw, painful, crusted wounds. The person feels generally ill. Blisters may be widespread, and once ruptured, they may become infected. When severe, pemphigus is as harmful as a serious burn. Similar to a burn, the damaged skin oozes large amounts of fluid and is prone to infection by many types of bacteria.

Diagnosis and Treatment

Doctors usually recognize pemphigus by its characteristic blisters, but the disorder is diagnosed with certainty by examining a sample of skin under a microscope (skin biopsy). Sometimes doctors use special chemical stains that allow antibody deposits to be seen under the microscope. Doctors differentiate pemphigus from bullous pemphigoid by noting the layers of skin involved and the particular appearance of the antibody deposits.

Without treatment, pemphigus is usually fatal. With treatment, 90% of people with pemphigus survive. High doses of corticosteroids are the mainstay of treatment. If the disease is controlled, the dose of corticosteroids is tapered. If the person does not respond to treatment or the disease flares up as the dose is tapered, an immunosuppressant, such as azathioprine or cyclophosphamide, is also given. People with severe pemphigus may also undergo plasmapheresis, a process in which antibodies are filtered from the blood (see Section 14, Chapter 171). Injections of gold salts are sometimes used. Immune globulin given intravenously is a new, safe and effective treatment for severe pemphigus. Some people respond well enough to discontinue drug therapy, whereas others must continue taking low doses of the drugs for long periods.

In a hospital, the raw skin surfaces require extraordinary care, similar to the care given to people with severe burns. Antibiotics may be needed to treat infections in ruptured blisters. Dressings, sometimes filled with petroleum jelly, can protect raw, oozing areas.