What Is the Difference between Pemphigus and Pemphigoid?

Pemphigus and pemphigoid are two similar but different diseases. They are both diseases of the immune system, attacking different cells, and both cause blisters, though they differ in the types of blisters they cause as well as their locations. Both diseases are incurable, but treating the blisters helps reduce symptoms.

As autoimmune diseases, pemphigus and pemphigoid produce antibodies that target specific cells that differ between the two diseases. Pemphigus attacks cells called desmogleins, which are special protein cells in the skin that bind skin cells together. Blisters occur when desmogleins separate. Pemphigoid, on the other hand, targets collagen proteins. Although symptoms of these two diseases are similar, there are several differences.

One of the differences between pemphigus and pemphigoid is the location of the blisters that form. Pemphigus blisters occur in the outer layer of skin, called the epidermis, and in the layers of membrane that line the organs of the body, called mucous membranes. Pemphigoid blisters occur where the epidermis and next layer, called the dermis, join together.

Another difference between pemphigus and pemphigoid is the type of blister each disease creates. A pemphigus blister is fragile, breaks easily, and leaves raw skin. A pemphigoid blister is tight and does not break easily, but it does cause pain and itchiness. Pemphigus blisters break more easily than pemphigoid blisters mainly because of their location in the epidermis. Pemphigoid blisters are more cushioned.

Pemphigoid and pemphigus each have individual types of the diseases. Types of these diseases are classified by the parts of the body where blisters primarily appear. Both diseases have common and rare forms.

Pemphigus vulgarus (PV) is the common type of pemphigus and causes blisters in the mouth. It is found to occur in people ages 40 to 60. Pemphigus foliaceus (PF) is a type that causes blisters that start on the scalp and progress to the face, back, and chest. Mouth blisters do not generally occur. Paraneoplastic pemphigus (PNP) is rare but more severe because it appears as a complication of lymphoma and causes irreversible lung damage.

Also referred to as connective tissue autoimmune skin disease, pemphigoid has three different types. Gestational pemphigoid occurs toward the end of pregnancy or immediately following childbirth. Bullous pemphigoid (BP) results in blisters on the upper arms, inner thighs, and chest. Mucous membrane pemphigoid (MMP), also known as cicatricial pemphigoid, is commonly found to occur in people ages 40 to 70. Blisters occur only in the mucous membrane of organs and can cause scars that have the potential of leading to disabilities.

Treatment for pemphigus and pemphigoid is similar. There is no cure for either disease. Managing the blister outbreaks, however, is possible. Topical and oral steroids are the first line of defense. Corticosteroid ointments help relieve itching and inflammation while oral steroids help reduce the immune system responses.

When steroids are not effective, immunosuppressive medicines may be necessary. These medications treat more severe instances of pemphigus and pemphigoid that do not respond well to corticosteroids initially. Immunosuppressant medicines are often prescribed temporarily and treatment is continued with steroids. For outbreaks that are accompanied by infection or are at risk for developing infection, antibiotics are prescribed.