Pemphigus foliaceus is an autoimmune disease that causes itchy blisters to form on your skin. It’s part of a family of rare skin conditions called pemphigus that produce blisters or sores on the skin, in the mouth, or on the genitals.

There are two main types of pemphigus:

  • pemphigus vulgaris
  • pemphigus foliaceus

Pemphigus vulgaris is the most common and most severe type. Pemphigus vulgaris affects not just the skin, but also the mucous membranes. It causes painful blisters to form in your mouth, on your skin, and in your genitals.

Pemphigus foliaceus causes small blisters to form on the upper torso and face. It’s milder than pemphigus vulgaris.

Pemphigus erythematosus is a type of pemphigus foliaceus that causes blisters to form only on the face. It affects people with lupus.

Pemphigus foliaceus causes fluid-filled blisters to form on your skin, often on your chest, back, and shoulders. At first the blisters are small, but they gradually grow and increase in number. Eventually they can cover your whole torso, face, and scalp.

The blisters break open easily. Fluid may ooze from them. If you rub your skin, the whole top layer can separate from the bottom later and peel off in a sheet.

After the blisters break open, they can form sores. The sores scale and crust over.

Although pemphigus foliaceus usually isn’t painful, you may feel pain or a burning sensation in the area of the blisters. The blisters may also itch.

Pemphigus foliaceus is an autoimmune disease. Normally, the immune system releases proteins called antibodies to fight off foreign invaders like bacteria and viruses. In people with an autoimmune disease, the antibodies mistakenly go after the body’s own tissues.

When you have pemphigus foliaceus, antibodies bind to a protein in the outer layer of your skin, called the epidermis. In this layer of skin are cells called keratinocytes. These cells produce the protein — keratin — that provides structure and support to your skin. When antibodies attack keratinocytes, they separate. Fluid fills the spaces they leave behind. This fluid creates the blisters.

Doctors don’t know what causes pemphigus foliaceus. A few factors can increase your likelihood of getting this condition, including:

  • having family members with pemphigus foliaceus
  • being exposed to the sun
  • getting an insect bite (in South American countries)

Several drugs have also been linked to pemphigus foliaceus, including:

  • penicillamine (Cuprimine), used to treat Wilson’s disease
  • angiotensin converting enzyme inhibitors such as captopril (Capoten) and enalapril (Vasotec), used to treat high blood pressure
  • angiotensin-II receptor blockers such as candesartan (Atacand), used to treat high blood pressure
  • antibiotics such as rifampicin (Rifadin), used to treat bacterial infections
  • nonsteroidal anti-inflammatory drugs (NSAIDs)

Pemphigus foliaceus can start at any age, but it most often affects people ages 50 to 60. People who are of Jewish heritage are at increased risk for pemphigus vulgaris.

The goal of treatment is to get rid of the blisters and heal the blisters you already have. Your doctor may prescribe corticosteroid cream or pills. This medicine brings down inflammation in your body. High doses of corticosteroids can cause side effects such as increased blood sugar levels, weight gain, and bone loss.

Other drugs used to treat pemphigus foliaceus include:

  • Immune suppressants. Drugs like azathioprine (Imuran) and mycophenolate mofetil (CellCept) prevent your immune system from attacking your body’s own tissues. The main side effect from these drugs is an increased risk for infection.
  • Antibiotics, antiviral drugs, and antifungal medicines. These can prevent the blisters from getting infected if they break open.

If blisters cover a lot of your skin, you might need to stay in the hospital for treatment. Doctors and nurses will clean and bandage your sores to prevent infection. You may get fluids to replace what you’ve lost from the sores.

Blisters that break open can become infected with bacteria. If the bacteria get into your bloodstream, they can cause a life-threatening infection called sepsis.

See your doctor if you have blisters on your skin, especially if they break open.

Your doctor will ask about your symptoms and examine your skin. They might remove a piece of tissue from the blister and send it to a lab for testing. This is called a skin biopsy.

You might also have blood test to look for antibodies your immune system produces when you have pemphigus foliaceus.

If you’ve been diagnosed with pemphigus already, you should contact your doctor if you develop:

  • new blisters or sores
  • a rapid spread in the number of sores
  • fever
  • redness or swelling
  • chills
  • weakness or achy muscles or joints

Some people get better without treatment. Others may live with the disease for many years. You might need to take medicine for years to prevent the blisters from coming back.

If a medication caused pemphigus foliaceus, stopping the drug can often clear up the disease.