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Posted by Elaine Moore Oct 23, 2006 |
Autoimmune pemphigus refers to several rare autoimmune dermatological conditions, which are characterized by blistering of the skin and mucous membranes. Pemphigus disorders belong to the family of Autoimmune Bullous Skin Diseases. There are several different types of pemphigus. Each of these disorders causes different symptoms and has a different disease course. The three main types of pemphigus include: paraneoplastic pemphigus, pemphigus vulgaris and pemphigus foliaceus. Other autoimmune conditions that cause blistering and may be confused with pemphigus include bullous pemphigus, bullous lupus, and Hailey-Hailey disease.
PARANEOPLASTIC PEMPHIGUS
Paraneoplastic diseases are those that occur in conjunction with certain cancers. Paraneoplastic conditions may occur either before or after the cancerous condition is detected. Paraneoplastic pemphigus usually occurs in patients who are already diagnosed with an internal cancer. Paraneoplastic pemphigus is the most serious form of pemphigus and it is the most rare of the three types. It is characterized by painful sores of the mouth, lips and esophagus and by several types of skin lesions. The lungs may also be affected, causing a condition known as bronchiolitis obliterans, which causes a potentially fatal destruction of alveoli in lung tissue.
Paraneoplastic pemphigus doesn't respond well to treatment. Its presence suggests the presence of a hidden tumor in patients not yet diagnosed with cancer. The tumor itself may be benign, and its surgical removal will usually improve the condition of pemphigus.
PEMPHIGUS VULGARIS
Pemphigus Vulgaris (PV)is the most common form of pemphigus and represents approximately 70 percent of all pemphigus disorders. The sores in PV may not always resemble blisters because of their tendency to form erosions. PV is caused by circulating antibodies that attack the skin and bind to the desmoglein-3 protein found on skin cells. This protein normally allows skin cells to adhere to one another. When this protein is destroyed, the skin cells separate, causing a condition of acantholysis that results in blistering of the skin and mucous membranes of the mouth, eyes and genitals.
PEMPHIGUS FOLIACEUS
Pemphigus foliaceus, which is the least severe form of pemphigus, is characterized by crusted, scaly sores, or fragile blisters that usually occur on the scalp, later spreading to the face, chest, and back. Oral or other mucocutaneous blisters do not occur in this disorder. Circulating antibodies in pemphigus foliaceus bind to desmoglein-1 protein (found on the surface of the top dry layer of skin) rather than to the desmoglein-3 protein affected in PV. Unlike the blisters seen in PV, the lesions in pemphigus foliaceus may itch and may easily be confused with eczema or dermatitis.
CAUSES OF PEMPHIGUS
The causes of pemphigus are unknown. In some cases pemphigus has been found to occur as a side effect of certain medications. Drugs suspected of triggering pemphigus include ACE inhibitors such as Elanapril and chelating agents such as penicillamine. Pemphigus is known to occur in people with other autoimmune disorders, primarily myasthenia gravis and in people with certain cancers, for instance, thyroid cancer.
DIANOSING PEMPHIGUS
Diagnosed is made by tissue studies of exudates taken from lesions or from skin biopsies. Direct immunofluoresent antibody (IFA) techniques can be used to demonstrate the presence of desmoglein antibodies in tissue samples. Blood tests for desmoglein antibodies are also used to determine the specific type of pemphigus that is present. Antibodies to desmoglein-1 are seen in pemphigus foliaceus, and antibodies to desmoglein-3 occur in pemphigus vulgaris.
TREATMENT OF PEMPHIGUS DISORDERS
Pemphigus is usually treated with high doses of oral corticosteroids, usually Prednisone, and cytotoxic drugs such as Imuran and Cytoxan, which are added to reduce the effects of the steroids. In cases of pemphigus foliaceus, hydroxychloroquine (Plaquenil) and Dapsone are sometimes used. Because of the toxicity of these medications, blood and urine tests must be performed regularly.
The lesions in pemphigus must be cleaned and topical corticosteroids are used to prevent erosion. The blisters in pemphigus are open wounds prone to infection. Antibiotics are frequently used to prevent infection. Infections are one of the primary causes of mortality in patients with pemphigus.
Resources:
Pemphigus, Dermatologic Disease Database, American Osteopathic College of Dermatology, www.aocd.org/skin/dermatologic_diseases/pemphigus.html.
International Pemphigus Foundation, http://www.pemphigus.org/