The Prevalence And Incidence Of Hidradenitis Suppurativa In Canada: Results From A Population-Based Survey


      Hidradenitis suppurativa (HS) is a chronic, inflammatory and debilitating skin disease that usually presents after puberty as subcutaneous nodules. Because HS is not routinely reported, its incidence is more likely underestimated. The prevalence of HS in the American and French general population is estimated at less than 1%, although point prevalence reports have reached 4% in Denmark. No published study reported the epidemiology of HS in Canada. The objective of this study was to estimate the prevalence and incidence of HS in the adult Canadian population.


      A questionnaire, including previously validated questions, was developed to determine the self-reported and the diagnosed prevalence and incidence of HS. For the self-reported prevalence, patients were questioned if they had described HS related symptoms. Diagnosed prevalence was assessed by asking participants if they have received a diagnosis of HS. This survey was administered to a web-based panel of respondents representing the general Canadian population.


      A total of 10,002 people of the general population were surveyed. In the past 6 months, 71% of patients had 2 boils or more which were mostly located in the axillia or armpits (48.4%) and in the groin (37.6%). The first symptoms appeared on average at 24.1 years old and at 28.1 years old in the diagnosed and the self-reported groups respectively. The prevalence of HS was 3.84% (2.36% and 1.49% in the diagnosed cases and the self-reported cases respectively), while the annual incidence was estimated at about 30 new cases per 10,000 population over a one year period.


      This was the first attempt to estimate HS prevalence in Canada. Closed to a 4% prevalence, results indicate that there is a relatively high proportion of patients with HS in Canada, but their distribution in terms of severity of the disease remains to be established.