Acta Dermato-Venereologica 99-12CompleteContent | Page 18

1127 CLINICAL REPORT Pemphigus Foliaceus and Pemphigus Erythematosus are the Most Common Subtypes of Pemphigus in Northern Finland Anna-Kaisa FÖRSTI 1,2# , Ossi VUORRE 3# , Eveliina LAURILA 4 , Jari JOKELAINEN 5 , Laura HUILAJA 2 and Kaisa TASANEN 2 1 Department of Dermatology, Mehiläinen Länsi-Pohja Oy, Kemi, 2 Department of Dermatology and Medical Research Center Oulu, PEDEGO Research Unit, University of Oulu, Oulu University Hospital, 3 Faculty of Medicine, University of Oulu, Oulu, 4 Jyväskylä Health Centre, Jyväskylä, and 5 Infrastructure for Population Studies, Faculty of Medicine, University of Oulu and Unit of General Practice, Oulu University Hospital, Oulu, Finland # These authors contributed equally. Pemphigus is an autoimmune skin disease characte- rized by blistering and erosions of the skin and mu- cous membranes. Pemphigus is rare in Northern and Western Europe, but its incidence is higher around the Mediterranean Sea. The most common type worldwide is pemphigus vulgaris. The aim of this study was to investigate the incidence of pemphigus subtypes in Northern Finland between 1985 and 2017. A total of 46 patients diagnosed with pemphigus at the Depart- ment of Dermatology of Oulu University Hospital were found; the female/male ratio was 1.7. In contrast to many other countries, it was found that, in Northern Finland, the superficial pemphigus subtypes were the most common: erythematosus or foliaceus (65%) fol- lowed by pemphigus vulgaris (26%). Over the past 4 decades the annual incidence of pemphigus in Finland has increased from 0.76 to 2.8 cases per million per- sons. Key words: autoimmune blistering skin disease; pemphigus; epidemiology; incidence; Finland. Accepted Aug 8, 2019; E-published Aug 9, 2019 Acta Derm Venereol 2019; 99: 1127–1130. Corr: Anna-Kaisa Försti, Mehiläinen Länsi-Pohja Oy, Department of Der- matology, Kauppakatu 25, FIN-94100 Kemi, Finland. E-mail: anna-kaisa. [email protected] P emphigus comprises a group of rare autoimmune bullous diseases, characterized by the production of autoantibodies against desmogleins, a family of epidermal adhesion proteins. Autoantibodies against desmogleins (Dsg) 1 and 3 cause loss of intraepidermal adhesion, resulting in epidermal acantholysis, bliste- ring and erosions of the skin and mucous membranes (1–4). Due to the rarity of pemphigus and the diversity of its variants, it is challenging to distinguish the dif- ferent types of pemphigus using clinical findings alone. Therefore, diagnosis of pemphigus relies on direct and indirect immunofluorescence microscopy, serology and histopathology. The gold standard diagnostic technique is direct immunofluorescence microscopy of skin biopsy, which reveals intercellular binding of immunoglobulin G (IgG) and/or complement 3 (C3) within the epidermis. In addition, Dsg antibodies are detectable by enzyme linked immunosorbent assays (ELISA) of patient sera, SIGNIFICANCE Pemphigus comprises a group of autoimmune skin diseases characterized by blistering and erosions of the skin and mucous membranes. Pemphigus is rare in Northern and Western Europe, but its incidence is higher around the Mediterranean Sea. The most common type worldwide is pemphigus vulgaris. To the best of our knowledge, there are no recent reports of the incidence of pemphigus in Nordic populations. The latest study into the incidence of pemphi- gus in Finland is from the 1970s. However, the incidence may have been affected, for example, by immigration. This is a retrospective database study of all patients with pem- phigus diagnosed in the Oulu University Hospital between 1985 and 2017. The current study included 46 patients, and interestingly, the most prevalent subtype was superficial pemphigus foliaceus or erythematosus (65%). This study also reports comorbidities of study patients and treatments used for pemphigus in the Oulu University Hospital. and the histology of skin biopsy can help to determine the sub-type of pemphigus (3, 4). The 2 main forms of pemphigus are pemphigus vulga- ris (PV) and pemphigus foliaceus (PF). A third notable type is paraneoplastic pemphigus, which is a rare variant associated with malignancies and a more severe clinical phenotype (2). An essential difference between PV and PF is the degree of mucosal involvement and serological status. PV generally begins in the oral mucous mem- branes and can be manifested in the skin, whereas PF typically exhibits skin symptoms only, with no mucosal involvement (5). In both PV and PF, the disease can be manifested in the skin, and Dsg 1 antibodies are then present. In PV manifesting solely on the mucous mem- branes, only Dsg 3 antibodies are detected. Dsg 1 and 3 antibodies also correlate with disease activity (2, 4). Pemphigus vegetans is a special form of PV, in which symptoms are predilected to axillary, umbilical, mam- mary and other intertriginous areas. Papillomatosis and fissured vegetation may develop. PF has its own variant, pemphigus erythematosus (PE), which resembles PF clinically, but usually has a less severe clinical manifes- tation that is limited to the face (1). The incidence of pemphigus varies significantly by geographical region and ethnicity. The reported incidence This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2019 Acta Dermato-Venereologica. doi: 10.2340/00015555-3280 Acta Derm Venereol 2019; 99: 1127–1130