Pemphigus ( or ) is a rare group of blistering autoimmune diseases that affect the skin and mucous membranes. The name is derived from the Greek root pemphix, meaning "pustule".In pemphigus, autoantibodies form against desmoglein, which forms the "glue" that attaches adjacent epidermal cells via attachment points called desmosomes. When autoantibodies attack desmogleins, the cells become separated from each other and the epidermis becomes detached, a phenomenon called acantholysis. This causes blisters that slough off and turn into sores. In some cases, these blisters can cover a large area of the skin.Originally, the cause of this disease was unknown, and "pemphigus" was used to refer to any blistering disease of the skin and mucosa. In 1964, researchers found that the blood of patients with pemphigus contained antibodies to the layers of skin that separate to form the blisters. In 1971, an article investigating the autoimmune nature of this disease was published. Types
The several types of pemphigus (pemphigus vulgaris, pemphigus foliaceus, intraepidermal neutrophilic IgA dermatosis, and paraneoplastic pemphigus) vary in severity. Skin lesions caused by pemphigus can lead to fatal infections, so treatment is extremely important. Pemphigus vulgaris (PV - ICD-10 L10.0) is the most common form of the disorder and occurs when antibodies attack desmoglein 3. Sores often originate in the mouth, making eating difficult and uncomfortable. Although PV may occur at any age, it is most common among people between 40 and 60. It is more frequent among Ashkenazi Jews. Rarely, it is associated with myasthenia gravis.
Diagnosis
Pemphigus defines a group of autoimmune intraepithelial blistering diseases that are characterized by loss of normal cell-cell adhesion (acantholysis), and by the presence of pathogenic (predominantly IgG) autoantibodies reacting against epithelial adhesion molecules. Pemphigus is further divided in two major subtypes: pemphigus vulgaris (PV) and pemphigus foliaceus (PF). However, several other disorders such as IgA pemphigus, IgE pemphigus, pemphigus herpetiformis, drug-induced pemphigus, Senear Usher syndrome, and endemic pemphigus foliaceus exist, and are recognized by a dermatologist from the appearance and distribution of the skin lesions. It is also commonly diagnosed by specialists practicing otolaryngology- head and neck surgery, periodontists, oral and maxillofacial surgeons, and eye doctors, as lesions can affect the eyes and mucous membranes of the oral cavity. Intraorally, it resembles the more common diseases lichen planus and mucous membrane pemphigoid. Definitive diagnosis requires examination of a skin or mucous membrane biopsy by a dermatopathologist or oral pathologist. The skin biopsy is taken from the edge of a blister, prepared for histopathology and examined with a microscope. The pathologist looks for an intraepidermal vesicle caused by the breaking apart of epidermal cells (acantholysis). Thus, the superficial (upper) portion of the epidermis sloughs off, leaving the bottom layer of cells on the "floor" of the blister. This bottom layer of cells is said to have a "tombstone" appearance. Definitive diagnosis also requires the demonstration of antidesmoglein autoantibodies by direct immunofluorescence on the skin biopsy. These antibodies appear as IgG deposits along the desmosomes between epidermal cells, a pattern reminiscent of chicken wire.