Author: Shahnawaz Towheed MS2, Y, Miller-Monthrope, Dermatologist/Dermatopathologist, Toronto, Canada, 2024

Definition: Pemphigus Vulgaris is an autoimmune blistering disorder affecting the skin and mucous membranes. 

Epidemiology: It has an incidence of approximately 1-5 cases per million people per year and predominantly affects middle-aged and older adults, with a higher prevalence in certain ethnic groups, such as the Ashkenazi Jewish population and patients of East Indian descent. 

Etiology: The condition is caused by autoantibodies against desmogleins, which are essential proteins in skin cell adhesion. 

Signs/ Symptoms: Clinically, it presents with flaccid blisters and erosions, particularly in the mouth, and can progress to involve the skin. 

Diagnosis: Diagnosis is confirmed through biopsies of involved skin and a biopsy for direct immunofluorescence of uninvolved skin, which shows IgG antibodies against the keratinocyte cell surface in a “chicken wire pattern”. 

Treatment: The treatment typically requires high-dose corticosteroids, and immunosuppressive agents like azathioprine, and rituximab.

Complications: The prognosis is generally favourable with appropriate management, though the condition can be chronic and require long-term treatment. Corticosteroids first used for PV in the 1950s reduced the mortality from 75% to 30%. This was further reduced to below 5% with the addition of other immunosuppressive agents introduced in the 1980s. 

References:

1.     Alpsoy E, Akman-Karakas A, Uzun S. Geographic variations in epidemiology of two autoimmune bullous diseases: pemphigus and bullous pemphigoid. Arch Dermatol Res. 2015;307(4):291-298. doi:10.1007/s00403-014-1531-1

2.     Russo I, De Siena FP, Saponeri A, Alaibac M. Evaluation of anti-desmoglein-1 and anti-desmoglein-3 autoantibody titers in pemphigus patients at the time of the initial diagnosis and after clinical remission. Medicine (Baltimore). 2017;96(46):e8801. doi:10.1097/MD.0000000000008801

3.     Kridin K, Sagi SZ, Bergman R. Mortality and Cause of Death in Patients with Pemphigus. Acta Derm Venereol. 2017 May 8;97(5):607-611. doi: 10.2340/00015555-2611. PMID: 28093595.

4.     Joly P, Maho-Vaillant M, Prost-Squarcioni C, et al. First-line rituximab combined with short-term prednisone versus prednisone alone for the treatment of pemphigus (Ritux 3): a prospective, multicentre, parallel-group, open-label randomised trial. Lancet. 2017;389(10083):2031-2040. doi:10.1016/S0140-6736(17)30070-3