Pemphigus
Overview
Pemphigus is a rare group of autoimmune blistering diseases that affect the skin and mucous membranes.
Causes
The real cause of this disorder is not known to medical research; however, it seems to be a case of autoimmune disease. In the case of Pemphigus vulgaris, the immune system starts to counteract specific proteins in healthy skin cells in the skin tissues or the mucous membranes. These particular type of proteins known as desmogleins are critical in binding skin cells to each other, in a normal human body.
Diagnosis
Pemphigus is recognized by a dermatologist from the appareance and distribution of the skin lesions. Definitive diagnosis requires examination of a skin biopsy by a dermatopathologist. 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 anti-desmoglein 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. Anti-desmoglein antibodies can also be detected in a blood sample using the ELISA technique. A high titre of cANCA (cellular Anti Neutrophil Cytoplasmic Antibody) is an important feature of the disease.
Treatment
If not treated, pemphigus can be fatal due to overwhelming infection of the sores. The most common treatment is the administration of oral steroids, especially prednisone. The side effects of cortico-steroids may require the use of so-called steroid-sparing or adjuvant drugs. The immuno-suppressant CellCept (Mycophenolic acid) is among those being used.[6] Intravenous gamma globulin (IVIG) may be useful in severe cases, especially paraneoplastic pemphigus. Mild cases sometimes respond to the application of topical steroids. Recently, Rituximab, an anti-CD20 antibody, was found to improve otherwise untreatable severe cases of Pemphigus vulgaris. [7][8] All of these drugs may cause severe side effects, so the patient should be closely monitored by doctors. Once the outbreaks are under control, dosage is often reduced, to lessen side effects. If paraneoplastic pemphigus is diagnosed with pulmonary disease, a powerful cocktail of immune suppressant drugs is sometimes used in an attempt to halt the rapid progression of bronchiolitis obliterans, including solumedrol, ciclosporin, azathioprine and thalidomide. Plasmapheresis may also be useful. If skin lesions do become infected, antibiotic may be prescribed. In addition, talcum powder is helpful to prevent oozing sores from adhering to bedsheets and clothes.