Pemphigus vulgaris (PV) is an acquired autoimmune bullous disease of the skin and mucous membranes. It is typically characterized by the presence of circulating pathogenic autoantibodies (predominantly immunoglobulin G4 [IgG4]) against desmoglein, a cadherin-family, keratinocyte cell surface adhesion molecule of the desmosome, although other antibody subtypes and autoantibodies against other antigenic targets have been described. The target antigens in PV are desmoglein 3 (Dsg3) with or without desmoglein 1 (Dsg1). More than half of patients have both skin and mucosal involvement. In the mucosal-dominant type of PV, autoantibodies against Dsg3 (anti-Dsg3 Ig) are typically present, and in the mucocutaneous type, autoantibodies against Dsg1 and Dsg3 are usually present; however, variations in these patterns can be seen in the real-world setting.

The estimated incidence worldwide is 0.76-5 cases per million per year, although PV occurs in higher incidences in individuals of Jewish ancestry, as well as in certain geographic areas (Middle East, Southeastern Europe, and India). Variants of the ST18 gene have been found to confer increased risk of PV in some populations. PV is typically a disease of adults, with average age of onset between 40 and 60 years, but PV rarely can occur in childhood and young adulthood. There does not appear to be a consistent sex predilection.

Almost all patients with PV develop painful erosions on the oral mucosa, and individuals with the mucocutaneous type also develop flaccid bullae, erosions, and crusted erosions / plaques on the skin.

Oral mucosal involvement is more common than genital involvement. The larynx, esophagus, conjunctiva, nasopharynx, and urethra can be involved rarely. Genital involvement is usually observed in the setting of extensive mucocutaneous disease and, as such, is considered a marker of disease severity and associated with treatment resistance and poor prognosis. In a small study (n=34), 44% of women had genital involvement of PV, and it was primarily observed in patients with moderate-to-severe mucocutaneous disease. PV is rarely seen in isolation on genital skin.

Patients with genital involvement typically present with erosions that can occur on the labia majora, labia minora, cervix, vagina, and clitoris.