Overview of Pemphigus
Pemphigus is a disease that causes blistering of the skin and the 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 the mucous membranes. People with the disease produce antibodies against desmogleins, proteins that bind skin cells to one another. When these bonds are disrupted, skin becomes fragile, and fluid can collect between its layers, forming blisters.
There are several types of pemphigus, but the two main ones are:
- Pemphigus vulgaris, which normally affects the skin and mucous membranes such as the inside of the mouth.
- Pemphigus foliaceus, which only affects the skin.
There is no cure for pemphigus, but in many cases, it is controllable with medications.
Who Gets Pemphigus?
You are more likely to get pemphigus if you have certain risk factors. These include:
- Ethnic background. While pemphigus occurs across ethnic and racial groups, some populations are at greater risk for certain types of the disease. People of Jewish (especially Ashkenazi), Indian, Southeast European, or Middle Eastern descent are more susceptible to pemphigus vulgaris.
- Geographic location. Pemphigus vulgaris is the most common type worldwide, but pemphigus foliaceus is more common in some places, such as certain rural regions of Brazil and Tunisia.
- Sex and age. Women get pemphigus vulgaris more frequently than men do, and the age of onset is usually between 50 and 60 years old. Pemphigus foliaceus generally affects men and women equally, but in some populations, women get the disease more frequently than men do. While the age of onset of pemphigus foliaceus is usually between 40 and 60 years old, in some areas, symptoms may begin in childhood.
- Genes. Scientists believe that the higher frequency of the disease in certain populations is partly due to genetics. For example, evidence shows that certain variants in a family of immune system genes called HLA are linked to a higher risk of pemphigus vulgaris and pemphigus foliaceus.
- Medications. In rare cases, pemphigus has resulted from taking certain medicines, such as certain antibiotics and blood pressure medications. Medicines that contain a chemical group called a thiol have also been linked to pemphigus.
- Cancer. Rarely, the development of a tumor—in particular a growth in a lymph node, tonsil, or thymus gland—can trigger the disease.
Types of Pemphigus
There are two major forms of pemphigus, and they are categorized based on the layer of skin where the blisters form and where the blisters are found on the body. The type of antibody that attacks the skin cells also helps define 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 other mucosal surfaces, as well as on the skin. They develop within a deep layer of the epidermis and are often painful. There is a subtype of the disease called pemphigus vegetans in which blisters form mainly in the groin and under the arms.
- Pemphigus foliaceus is less common and only affects the skin. The blisters form in upper layers of the epidermis and may be itchy or painful.
Other rare forms of pemphigus include:
- Paraneoplastic pemphigus. This type is characterized by sores in the mouth and on the lips, but blisters or inflamed lesions usually also develop on the skin and other mucosal surfaces. Severe lung problems may occur with this type. People with this type of the disease usually have a tumor, and the disease may improve if the tumor is surgically removed.
- IgA pemphigus. A type of antibody called IgA causes this form. Blisters or pimple-like bumps often appear in groups or rings on the skin.
- Drug-induced pemphigus. Certain medicines, such as some antibiotics and blood pressure medications, as well as drugs that contain a chemical group called a thiol, may bring on pemphigus-like blisters or sores. The blisters and sores usually go away when you stop taking the medication.
Pemphigoid is a disease that is different from pemphigus but shares some of its features. Pemphigoid produces a split where the epidermis and the underlying dermis meet, causing deep, rigid blisters that do not break easily.
Symptoms of Pemphigus
The main symptom of pemphigus is blistering of the skin and in some cases, the mucosal surfaces, such as the inside of the mouth, nose, throat, eyes, and genitals. The blisters are fragile and tend to burst, causing crusty sores. Blisters on skin may join together, forming raw-looking areas that are prone to infection and that ooze large amounts of fluid. The symptoms vary somewhat depending on the type of pemphigus.
- Pemphigus vulgaris blisters often start in the mouth, but later on, they can develop on the skin. The skin may become so fragile that it peels off by rubbing a finger on it. Mucosal surfaces such as those of the nose, throat, eyes, and genitals may also be affected.
Blisters form within the deep layer of the epidermis, and they are often painful.
- Pemphigus foliaceus only affects the skin. Blisters often appear first on the face, scalp, chest, or upper back, but they may eventually spread to other areas of skin on the body. The affected areas of skin may become inflamed and peel off in layers or scales. The blisters form in the upper layers of the epidermis, and they may be itchy or painful.
Causes of Pemphigus
Pemphigus is an autoimmune disorder that happens when the immune system attacks healthy skin. Immune molecules called antibodies target proteins called desmogleins, which help link neighboring skin cells to one another. When these connections are broken, skin becomes fragile and fluid can collect between layers of cells, forming blisters.
Normally, the immune system protects the body from infection and disease. Researchers do not know what causes the immune system to turn on the body’s own proteins, but they believe that both genetic and environmental factors are involved. Something in the environment may trigger pemphigus in people who are at risk because of their genetic makeup. In rare cases, pemphigus may be caused by a tumor or by certain medications.