Pemphigus

Overview of pemphigus

Pemphigus is a disease that causes blisters to form on the skin and inside of the mouth, nose, throat, eyes, and genitals. The disease is rare in the United States.

Pemphigus is an autoimmune disease in which the immune system mistakenly attacks cells in the top layer of the skin (epidermis) and mucous membranes. People with this condition produce antibodies against desmogleins, proteins that bind skin cells to each other. When these bonds are broken, the skin becomes brittle and fluid can accumulate between its layers, forming blisters.

There are several types of pemphigus, but the main two are:

• Pemphigus vulgaris, which usually affects the skin and mucous membranes, such as the inside of the mouth.
• Pemphigus foliaceus, affecting only the skin.

There is no cure for pemphigus, but in many cases it can be controlled with medication.

Who gets pemphigus?

You are more likely to get pemphigus if you have certain risk factors. This includes:

• Ethnic background. While pemphigus occurs among ethnic and racial groups, certain populations are at greater risk for certain types of the disease. People of Jewish (especially Ashkenazi), Indian, Southeast European, or Middle Eastern ancestry are more susceptible to pemphigus vulgaris.
• Geographical position. Pemphigus vulgaris is the most common type worldwide, but pemphigus foliaceus is more common in some places, such as some rural areas in Brazil and Tunisia.
• Gender and age. Women get pemphigus vulgaris more often than men, and the age of onset is usually between 50 and 60 years of age. Pemphigus foliaceus usually affects men and women equally, but in some populations, women are more affected than men. Although the age of onset of pemphigus foliaceus is usually between 40 and 60 years of age, in some areas, symptoms may appear during childhood.
• Genes. Scientists believe that the higher incidence of the disease in certain populations is due in part to genetics. For example, data show that certain variants in a family of immune system genes called HLA are associated with a higher risk of pemphigus vulgaris and pemphigus foliaceus.
• Medications. Rarely, pemphigus occurs as a result of taking certain medications, such as certain antibiotics and blood pressure medications. Medicines containing a chemical group called thiol have also been linked to pemphigus.
• Cancer. In rare cases, the development of a tumor, in particular the growth of a lymph node, tonsil or thymus gland, can provoke the disease.

Types of pemphigus

There are two main forms of pemphigus and they are classified according to the layer of skin where the blisters form and where the blisters are located on the body. The type of antibodies attacking the skin cells also helps determine the type of pemphigus.

The two main forms of pemphigus are:

• Pemphigus vulgaris is the most common type in the United States. Blisters form in the mouth and on other mucosal surfaces, as well as on the skin. They develop in the deep layers of the epidermis and are often painful. There is a subtype of the disease called pemphigus autonomicus, in which blisters form primarily in the groin and under the armpits.
• Leaf pemphigus less common and affects only the skin. Blisters form in the upper layers of the epidermis and may be itchy or painful.

Other rare forms of pemphigus include:

• Paraneoplastic pemphigus. This type is characterized by mouth and lip ulcers, but usually also blistering or inflamed lesions on the skin and other mucous membranes. With this type, severe lung problems can occur. People with this type of disease usually have a tumor, and the disease may improve if the tumor is removed surgically.
• IgA pemphigus. This form is caused by a type of antibody called IgA. Blisters or bumps often appear in groups or rings on the skin.
• medicinal pemphigus. Some medications, such as some antibiotics and blood pressure medications, and drugs that contain a chemical group called thiol, can cause blisters or pemphigus-like sores. The blisters and sores usually disappear when you stop taking the medicine.

Pemphigoid is a disease that is distinct from pemphigus but shares some common features. Pemphigoid causes splitting at the junction of the epidermis and underlying dermis, resulting in deep hard blisters that are not easily broken.

Symptoms of pemphigus

The main symptom of pemphigus is blistering of the skin and, in some cases, mucous membranes such as the mouth, nose, throat, eyes, and genitals. The blisters are brittle and tend to burst, causing hard sores. Blisters on the skin may coalesce, forming rough patches that are prone to infection and produce large amounts of fluid. Symptoms vary somewhat depending on the type of pemphigus.

• Pemphigus vulgaris blisters often start in the mouth, but they may later appear on the skin. The skin can become so brittle that it flakes off when rubbed with a finger. Mucous membranes such as the nose, throat, eyes, and genitals may also be affected.

  The blisters form in the deep layer of the epidermis and are often painful.

• Leaf pemphigus only affects the skin. Blisters often first appear on the face, scalp, chest, or upper back, but they can spread to other areas of the body over time. Affected areas of the skin may become inflamed and flaky in layers or scales. Blisters form in the upper layers of the epidermis and may be itchy or painful.

Causes of pemphigus

Pemphigus is an autoimmune disease that occurs when the immune system attacks healthy skin. Immune molecules called antibodies target proteins called desmogleins, which help bind neighboring skin cells to each other. When these bonds are broken, the skin becomes brittle and fluid can pool between the layers of cells, forming blisters.

Normally, the immune system protects the body from infections and diseases. Researchers don't know what causes the immune system to turn on the body's own proteins, but they believe both genetic and environmental factors are involved. Something in the environment can trigger pemphigus in people who are at risk due to their genetic predisposition. Rarely, pemphigus can be caused by a tumor or certain medications.