Prevalence of Hidradenitis Suppurativa in Lund and Gothenburg, Sweden: An Analysis from the Global Hidradenitis Suppurativa Atlas Initiative

Abstract Introduction: Epidemiologic studies of hidradenitis suppurativa (HS) from Sweden are limited. The aim of this study was to investigate the prevalence of HS in Lund and Gothenburg, Sweden. Methods: This study was a part of the Global Hidradenitis Suppurativa Atlas (GHiSA) initiative. The study was multicentered and included apparently healthy adults accompanying a patient to the Department of either Endocrinology or Ophthalmology in a Swedish University Hospital from February 1 to November 30, 2023. Recruitment occurred in the waiting rooms where the study participants were consecutively invited to answer a validated screening questionnaire which had been translated into Swedish. In the questionnaire, the key screening questions asked were whether the study participant had had 2 or more boils/abscesses in the past 6 months and if these were in any of the typical skin sites for HS. Screen-positive and randomly selected screen-negative participants were clinically examined for HS by a dermatologist to verify the results. Results: A total of 551 accompanying adults were approached of which 505 answered the questionnaire. The prevalence of HS in this sample was 0.99% (95% confidence interval [0.43% 2.30%]). There was a statistically significant difference in BMI between the HS and control group, but not in relation to age or sex. Conclusion: HS appears to be a common chronic disease in Sweden. Also, there is a strong association between overweight/obesity and HS.