Pemphigus vulgaris - Anogenital in
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.
L10.0 – Pemphigus vulgaris
49420001 – Pemphigus vulgaris
Differential Diagnosis & Pitfalls
- IgG/IgA pemphigus – A rarely reported condition. Unclear whether it represents a separate entity or pemphigus vulgaris that is transitioning to IgA pemphigus. Clinical findings in a recently reported series resembled pemphigus vulgaris, pemphigus foliaceus, and IgA pemphigus. In IgG/IgA pemphigus, dapsone can be used as an ancillary treatment.
- Mucous membrane pemphigoid – Can be isolated to the vulva, or it may involve the vulva as part of a more generalized presentation.
- Bullous pemphigoid – This autoimmune bullous dermatosis is less likely to have genital involvement and can be distinguished by histological and immunofluorescence studies.
- Aphthous ulcers
- Behçet disease
- Herpes simplex virus (HSV) – The genital ulcerations may be diffuse but are composed of smaller lesions (1-2 mm) that coalesce. Unlike pemphigus, significant cutaneous involvement in genital herpes would be unusual.
- Reactive nonsexually related acute genital ulcers (RNSRAGU)
- Pemphigus foliaceus
- Paraneoplastic pemphigus – Associated with underlying neoplasms (non-Hodgkin lymphoma, chronic lymphocytic leukemia, Castleman disease, thymomas, sarcomas, Waldenström macroglobulinemia).
- Erythema multiforme
- Stevens-Johnson syndrome – Usually drug induced and accompanied by high fever, skin tenderness, mucosal erosions, and desquamation 1-3 weeks after starting the inciting medication.
- Epidermolysis bullosa acquisita
- Hailey-Hailey disease
- Contact dermatitis
- Lichen planus
Drug Reaction Data