Pemphigus

Pemphigus is a group of rare autoimmune diseases that cause blistering of the skin and mucous membranes (mouth, nose, throat, eyes, and genitals). Some forms of the disease, including the most common form, may be fatal if left untreated.

What Causes Pemphigus?

Normally, our immune system produces antibodies that attack viruses and harmful bacteria to keep us healthy. In people with pemphigus, however, the immune system mistakenly attacks the cells in the epidermis, or top layer of the skin, and the mucous membranes. 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.

It is unclear what triggers the disease, although it appears that some people have a genetic susceptibility. Environmental agents may trigger the development of pemphigus in people who are likely to be affected by the disease because of their genes. In rare cases, it may be triggered by certain medications. In those cases, the disease usually goes away when the medication is stopped.

Is Pemphigus Contagious?

Pemphigus is not contagious. It does not spread from person to person.

Is Pemphigus Hereditary?

Though there can be a genetic predisposition to develop pemphigus, there is no indication that the disease is hereditary.

Who Gets Pemphigus?

Pemphigus affects people across racial and ethnic lines. Research has shown that certain ethnic groups (such as the eastern European Jewish community and people of Mediterranean descent) are more susceptible to pemphigus. A particular type of pemphigus occurs more frequently in people who live in the rain forests of Brazil.

Men and women are equally affected. Research studies suggest a genetic predisposition to the disease. Although the onset usually occurs in middle-aged and older adults, all forms of the disease may occur in young adults and children.

What Are the Different Types of Pemphigus?

There are several types of pemphigus and other similar blistering disorders. The type of disease depends on where (what layer) in the skin the blisters form and where they are located on the body. Blisters always occur on or near the surface of the skin, which is called the epidermis. People with pemphigus vulgaris, for example, have blisters that occur within the lower layer of the epidermis, while 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 in the United States. Soft and limp blisters appear on healthy-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, and are often painful. 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 immunoglobulin A or 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.
• Paraneoplastic pemphigus is a rare disease that is distinct from pemphigus, but shares some features of it. It occurs in people with certain types of cancer, including some lymphomas and leukemias. It often involves severe ulcers of the mouth and lips, cuts and scarring of the lining of the eye and eyelids, and skin blisters. Because the antibodies also target the membranes lining the airways, patients may develop life-threatening problems in the lungs. This disease is different from pemphigus, and the antibodies in the blood are different. Special tests may be needed to identify paraneoplastic pemphigus.

How is Pemphigus Diagnosed?

A diagnosis of pemphigus has several parts:

• A visual examination by a dermatologist. The doctor will take a complete history and physical exam, noting the appearance and location of the blisters.
• A blister biopsy. A sample of a blister is removed and examined under the microscope. The doctor will look for cell separation that is characteristic of pemphigus, and will also 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 exists.
• 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. Once treatment begins, this blood test may also be used to find out if treatment is working.

Pemphigus is a serious disease, and it is important to do all of these tests to confirm a diagnosis. No single test is right all of the time.

Because it is rare, pemphigus is often the last disease considered during diagnosis. Early diagnosis may permit successful treatment with only low levels of medication, so consult a doctor if you have persistent blisters on the skin or in the mouth. In the most common form of pemphigus (pemphigus vulgaris), the mouth is often the first place that blisters or sores appear.

What Type of Doctor Treats Pemphigus?

Pemphigus is a rare disease of the skin; therefore, dermatologists are the doctors best equipped to diagnose and treat people with pemphigus. If you have blisters in the mouth, a dentist can provide guidance for maintaining good oral health. This is important for preventing gum disease and tooth loss.

How Is Pemphigus Treated?

Treatment for pemphigus vulgaris may involve using one or more drugs. The main goal is to suppress the immune system so that it will stop attacking the tissues. Your doctor may prescribe corticosteroids and immunosuppressive drugs.

For more information on Pemphigus vulgaris

Source: NIAMS