Pemphigus causes blisters on your skin and mucous membranes. The blisters rupture easily, leaving open sores, which may ooze and become infected.

The signs and symptoms of two common types of pemphigus are as follows:

• Pemphigus vulgaris. This type usually begins with blisters in your mouth and then on your skin or genital mucous membranes. The blisters typically are painful but don't itch. Blisters in your mouth or throat may make it hard to swallow and eat.
• Pemphigus foliaceus. This type causes blisters on the chest, back and shoulders. The blisters tend to be more itchy than painful. Pemphigus foliaceus doesn't cause mouth blisters.

Pemphigus is distinct from bullous pemphigoid, which is a blistering skin condition that affects older adults and may cause death.

Pemphigus is an autoimmune disorder. Normally, your immune system produces antibodies to fight off harmful invaders, such viruses and bacteria. But in pemphigus, the body produces antibodies that damage cells of your skin and mucous membranes.

Pemphigus isn't contagious. In most cases, it's unknown what triggers the disease.

Rarely, pemphigus is triggered by the use of angiotensin-converting enzyme inhibitors, penicillamine and other drugs.

Your risk of pemphigus increases if you're middle-aged or older. The condition tends to be more common in people of Middle Eastern or Jewish descent.

Possible complications of pemphigus include:

• Infection of your skin
• Infection that spreads to your bloodstream (sepsis)
• Malnutrition, because painful mouth sores make it difficult to eat
• Medication side effects, such as high blood pressure and infection
• Death, if certain types of pemphigus are left untreated