Pemphigus is a category skin diseases that cause blisters to form on the skin and mucous membranes (mouth, nose, throat, eyes). This produces painful raw areas on the skin and mouth that will not heal. In some cases, these sores can cover a significant area of the skin and are at risk of becoming infected.
Pemphigus is a type of autoimmune disease that results from the body’s immune system attacking the skin. The immune system produces antibodies against proteins in the skin known as desmogleins. These proteins form the glue that keeps skin cells attached and the skin intact. When desmogleins are attacked, skin cells separate from each other and fluid can collect between the layers of skin, forming blisters that do not heal. In some cases, these blisters can cover a large area of skin. (Pemphigus is not contagious).
It is unclear what triggers pemphigus in some people. Although it appears people may inherit genes that increase their risk of developing pemphigus, there are other factors that may be required to trigger the disease in those who are susceptible. In rare cases, pemphigus may be triggered by medications. In such cases, the disease usually goes away after the medication is stopped.
Different Types of Pemphigus
There are several types of pemphigus. The type of disease depends on what layer in the skin the blisters form and where they are located on the body. People with pemphigus vulgaris, for example, have blisters that occur in the lower layer of the epidermis, whereas people with pemphigus foliaceus have blisters that form in the topmost layer. The type of antibody that is attacking the skin cells may also define the type of disease present.
- Pemphigus vulgaris is the most common type of pemphigus. Pemphigus vulgaris usually starts in middle-aged and older adults, but is can occur at any age. Painful blisters appear on normal-looking skin and mucous membranes. The sores almost always start in the mouth. The blisters of pemphigus vulgaris form within the deep layer of the epidermis. Blistered skin becomes so fragile that it may peel off by rubbing a finger on it. The blisters normally heal without scarring, but pigmented spots (spots where skin appears darker than the surrounding skin) may remain for a number of months.
- Pemphigus vegetans is a form of pemphigus with thick sores in the groin and under the arms.
- Pemphigus foliaceus involves crusted sores or fragile blisters that often appear first on the face and scalp and later on the chest and other parts of the body. Unlike pemphigus vulgaris, blisters do not form in the mouth. The sores are superficial and often itchy, and are rarely as painful as pemphigus vulgaris blisters. There may also be loose, moist scales on the skin.
- IgA pemphigus is a blistering disorder in which a different type of antibody binds to the cell surface of epidermal cells. This disease is different from other forms of pemphigus because it involves a different type of antibody (called IgA) than other types. The disease may result in blisters similar to those seen in pemphigus foliaceus, or it may involve many small bumps containing pus. This is the most benign, or least harmful, form of pemphigus.
What Is Pemphigoid?
Pemphigoid is another blistering skin disease caused by autoimmunity. It is a different disease despite the similar name. Pemphigoid produces a split in the cells where the epidermis and the dermis (the layer below the epidermis) meet, causing deep, tense (taut or rigid) blisters that do not break easily. Pemphigus, on the other hand, causes a separation within the epidermis, and the blisters are soft, limp, and easily broken.
Pemphigoid is seen most often in the elderly and may be fatal. Usually, both pemphigus and pemphigoid are treated with similar medications. Severe cases may require different approaches to treatment.
Diagnosis of Pemphigus
There are several medical tests that may be used to help diagnose pemphigus.
- A blister biopsy. A sample of the blistered skin is removed and examined under the microscope to determine the layer of skin in which the cells are separated.
- Direct immunofluorescence. A biopsy of a skin sample is treated in the laboratory with a chemical compound to find the abnormal desmoglein antibodies that attack the skin. The specific type of antibodies that form may indicate what type of pemphigus is present
- Indirect immunofluorescence. Sometimes called an antibody titre test, a sample of blood is tested to measure pemphigus antibody levels in the blood and to help determine the severity of the disease. This test may also be used to determine if someone is responding to treatment.
Treatment of Pemphigus
The recommended treatment will depend on the type of pemphigus and the severity of the disease.
Many patients will go into complete remission with treatment, although this may take a number of years. Other patients will need to continue to take small doses of medication to keep the disease under control.
Treatment often begins with one, or more medications, typically a high-dose corticosteroid (prednisone). This is an anti-inflammatory medication that suppresses the immune system. High doses are often required to bring pemphigus under control. Corticosteroids may be taken by mouth, or applied directly to the skin (topical corticosteroids)
After the skin condition is brought under control, the prescribed dose of corticosteroid is reduced to the lowest levels possible to keep symptoms under control.
Immunosuppressive medications may also be prescribed to minimize the use of corticosteroids, including mycophenolate mofetil, azathioprine, cyclophosphamide, and methotrexate.
All of these medications can cause serious side effects. You should see your doctor regularly for blood and urine tests. Be sure to report any problems or side effects you experience to the doctor.
With prolonged high-dose corticosteroid therapy, common side effects include susceptibility to life-threatening infections, delayed wound healing, osteoporosis, cataracts, glaucoma, type 2 diabetes, loss of muscle mass, peptic ulcers, swelling of the face and upper back, and salt and water retention.
To reduce the risk of osteoporosis, bone density measurements are taken, and patients with low bone density are prescribed osteoporosis medications, such as alendronate or risedronate. Extra calcium and vitamin D intake, exercise, and stopping smoking are also recommended. For diabetes caused by steroid use, patients must be on a low sugar diet and may need to take diabetes medications.
The immunosuppressive drugs that are used to treat pemphigus can also increase the chances of developing an infection and may cause anemia (a decrease in the white blood cells in the blood) inflammation of the liver, nausea, vomiting, or allergic reactions.
People with severe pemphigus that cannot be controlled with corticosteroids may undergo plasmapheresis, a treatment in which the blood containing the damaging antibodies is removed and replaced with blood that is free of antibodies. Such patients can also be treated with IVIG, or intravenous immunoglobulin, which is given daily for 3 to 5 days, every 2 to 4 weeks for 1 to several months. Plasmapheresis and IVIg are both very expensive treatments, since they require large amounts of donated and specially processed blood. Scientists have reported success in treating difficult cases of pemphigus vulgaris with a combination of IVIg and rituximab, a cancer medication.
It may take several months to years for the ulcers and blisters of pemphigus vulgaris to disappear after treatment has begun because circulating antibodies remain in the blood for a long time. Lesions in the mouth are particularly slow to heal. Blisters in the mouth can make brushing the teeth painful, leaving you prone to gum disease and tooth loss. A dentist can offer approaches that enable you to maintain healthy teeth and gums. Avoiding spicy, hard, and acidic foods will help, since those foods can irritate or trigger the blisters. If you are taking corticosteroids, you should receive advice for maintaining a diet low in calories, fat, and sodium, and high in potassium and calcium.
Reference: National Institute of Arthritis and Musculoskeletal and Skin Diseases
Last updated June 2013