INVESTIGATIVE REPORT
1095 Advances in dermatology and venereology ActaDV Acta Dermato-Venereologica ActaDV
Pemphigus Vulgaris and Pemphigus Foliaceus: Differences in Epidemiology and Mortality
Khalaf KRIDIN 1, Shira ZELBER-SAGI 2 and Reuven BERGMAN 1
1
Department of Dermatology, Rambam Health Care Campus and Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, and 2 School of Public Health, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, Israel
Little is known about differences in epidemiological features and prognosis between pemphigus vulgaris( PV) and pemphigus foliaceus( PF). The objective of this study was to compare PV and PF patients regarding ethnic variations and mortality rates. Mortality of PV and PF patients was compared with age- and sex-matched control subjects in the general population. The study cohort comprised 207 patients with PV and 30 with PF diagnosed during the period 2000 to 2015. The incidence rate of PV among Jews was 3.6- fold high er than among Arabs( p < 0.001), whereas no ethnic predisposition to PF was noted( p = 0.379). The risk of death for patients with PV was almost 3-fold higher than in the general population( standardized mortality ratio( SMR) 2.6). For patients with PF, the risk of mortality was not significantly increased relative to the general population( SMR 1.4). There is a racial predisposition to PV, whereas PF is sporadic. Mortality among patients with PV is higher compared with PF and the general population.
Key words: pemphigus; vulgaris; foliaceus; epidemiology; mortality; prognosis.
Accepted May 22, 2017; Epub ahead of print May 24, 2017 Acta Derm Venereol 2017; 97: 1095 – 1099.
Corr: Khalaf Kridin, Department of Dermatology, Rambam Health Care Campus, POB 9602, Haifa 31096, Israel. E-mail: dr _ kridin @ hotmail. com
Pemphigus is a rare, chronic, potentially life-threatening, autoimmune blistering disease of the skin and mucous membranes. It has 2 major subtypes: pemphigus vulgaris( PV) and pemphigus foliaceus( PF). The aetiopathogenesis of pemphigus is characterized by acantholysis and intraepidermal blister formation, resulting from IgG autoantibodies directed against desmoglein( Dsg) 3( PV) and / or Dsg 1( PF), 2 transmembrane desmosomal glycoproteins( 1, 2).
Pemphigus has an uneven geographical and ethnic distribution. We recently reported that the incidence rate of all variants of pemphigus in northern Israel was 3-fold higher among Jews than among Arabs( the major ethnic populations in Israel), with an overall annual incidence of 7.2 / million( 3). The annual incidence of PV is variable, and ranges from 0.76 / million in Finland( 4) to 16.1 / million in Jerusalem( 5). In most populations PF is less common than PV, and the estimated annual incidence varies between 0.5 – 1.0 / million in Western Europe( 6) to 6.7 / million in Tunisia( 7). PF is rare and sporadic worldwide, and its ethnic predominance is yet to be demonstrated( 8).
The mainstay treatments for pemphigus are systemic corticosteroids and immunosuppressive therapy. The prognosis for patients with pemphigus has improved greatly since the introduction of corticosteroid therapy; nevertheless, pemphigus remains a potentially life-threatening disease( 6), with a relatively high mortality rate after diagnosis, ranging from 5 % to 30 % during various lengths of follow-up( 9 – 11). In 2 recent studies from the UK and Taiwan, the risk of death was calculated as 2-to- 3-fold higher than in the control or general population( 12, 13). We have demonstrated previously that overall mortality of patients with pemphigus is 2.4-times greater than for the general population( 14).
The differences in the risk of overall mortality in patients with PV and PF relative to the general population have not yet been investigated. Moreover, the mortality of PF, as a distinct disease relative to the general population, has not been profiled.
The objectives of this study were to investigate and compare the 2 major subtypes of pemphigus regarding:( i) the incidence rate in 2 distinct ethnic populations; and( ii) mortality rates compared with the general population, by tracking an immunopathologically validated large cohort of consecutive PV and PF patients over an extended period of time. The data obtained represent the first comparison between PV and PF patients regarding mortality rates relative to the general population.
MATERIALS AND METHODS Study population
The study comprised all Israeli patients in Haifa( population: 875,000) and the northern( population: 691,000) districts with a new diagnosis of PV or PF from the beginning of January 1990 to the end of December 2015( 2008 census). The study cohort also included 16 patients diagnosed between 1985 and 1989, and followed up intensely during the study period.
To assess the incidence of PV and PF for an extended duration, we conducted a retrospective cohort study from January 2000 to December 2015. Incidence data are more reliable from 2000 due to the installation of a computerized system in our institute, which enables confirmation of every PV or PF case, and due to a better accessibility to the Israeli census. Rambam Health Care Campus is the tertiary referral centre providing dermatology services for the entire north-west region of Israel, and is the only hospital in the region that offers diagnostic laboratory immunopathology sample analysis. Thus, regional patients with suspected pemphigus are
This is an open access article under the CC BY-NC license. www. medicaljournals. se / acta Journal Compilation © 2017 Acta Dermato-Venereologica. doi: 10.2340 / 00015555-2706 Acta Derm Venereol 2017; 97: 1095 – 1099