Epidemiology of pemphigus in Sofia, Bulgaria. A 16-year retrospective study (1980-1995)

Background Pemphigus is a disease showing an uneven geographical distribution. In Bulgaria pemphigus has always represented a substantial part of diagnosed bullous diseases, but previous epidemiological data are incomplete. Our purpose was to evaluate retrospectively the incidence and prevalence of pemphigus in the district of Sofia (the capital of Bulgaria; population 1 200 000) for a sixteen-year period. Methods The files of all the newly registered patients with pemphigus in the City Hospital of Dermatology in Sofia during the period Jan 1 1980 to Dec 31 1995, were collected and analysed with regard to personal statistics, ethnic origin, profession, history of the disease including age and season of onset, symptoms, clinical diagnosis, severity, laboratory findings, associated illnesses, therapy, and cure rate. Special attention was paid to smoking, alcohol abuse, and the presence of triggering factors such as emotional stress, drug intake, underlying diseases, neoplasias, or others. Results During the 16-year period studied, 74 newly diagnosed cases of pemphigus occurred in the district of Sofia, giving a prevalence of 0.38 per 100 000 inhabitants and a mean incidence of 0.47/100 000/year for the overall population and 0.51/100 000/year for the population aged above 20 years. The most common clinical variant is pemphigus vulgaris, frequently occurring in the fifth-sixth decades. The vast majority of the patients are workers or professionals. Conclusions The results of the present retrospective study reveal a relatively high prevalence and incidence of pemphigus in Bulgaria, compared to that encountered in other countries. Our data is similar to that reported from Greece. Whether the Balkan Peninsula represents a focus of population groups with high susceptibility to pemphigus is a problem which could be highlighted by further epidemiological studies in this geographic area.