Question: What is (are) Pemphigus vulgaris ?
Answer: Pemphigus vulgaris is an autoimmune disorder that involves blistering of the skin and mucous membranes. It occurs almost exclusively in middle-aged or older people. Many cases begin with blisters in the mouth, followed by skin blisters that may come and go. In most cases, the exact cause of pemphigus vulgaris is unknown. It has rarely been observed in multiple members of the same family. Treatment is aimed at reducing symptoms and preventing complications. Severe cases are treated similarly to severe burns.
Source: GARD

Question: What causes Pemphigus vulgaris ?
Answer: What causes pemphigus vulgaris? Pemphigus vulgaris is an autoimmune disorder. The immune system produces antibodies against specific proteins in the skin and mucous membranes. These antibodies create a reaction that cause skin cells to separate. Although it is rare, some cases of pemphigus vulgaris are caused by certain medications. Medications that may cause this condition include: Blood pressure medications called ACE inhibitors Chelating agents such as penicillamine, which remove certain materials from the blood While in many cases the exact cause of pemphigus vulgaris remains unknown, several potentially relevant factors have been identified. Genetic factors: Predisposition to pemphigus is linked to genetic factors.Certain major histocompatibility complex (MHC) class II molecules, in particular alleles of human leukocyte antigen (HLA) DR4, appear to confer susceptibility to pemphigus vulgaris. Age: Peak age of onset is from 50-60 years. Infants with neonatal pemphigus typically recover after protection from their mother's antibodies have cleared their systems. The disease may, nonetheless, develop in children or in older persons, as well. Disease association: Pemphigus commonly occurs in individuals who also have other autoimmune diseases, particularly myasthenia gravis and thymoma. Pemphigus is not contagious. It does not spread from person to person. Though there can be a genetic predisposition to develop pemphigus, there is no indication the disease is hereditary.
Source: GARD