Prevalence of self-reported hidradenitis suppurativa patients in a cohort of Danish blood donors - a cross-sectional study.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by recurrent inflamed nodules. No pathognomonic test is available for HS, hence the diagnosis is based on three clinical criteria. We used a questionnaire previously developed for diagnosis of HS to estimate the cross-sectional prevalence and characterize HS patients in the Danish Blood Donor Study cohort.

METHOD: A questionnaire containing the HS screening questions, the Major Depression Inventory, the Short Form-12, as well as questions about height, weight and drinking habits was answered by 27,725 blood donors.

RESULTS: The prevalence of HS was 1.8% (confidence interval 95%: 1.6% - 2.0%) in the cohort of Danish blood donors. Donors with HS were on average 4.7 years younger (P<0.001), had 2.7 kg/m2 higher mean BMI (P<0.001) and were significantly more likely to smoke (OR 1.44, 17.9% vs 12.1%, P=0.002) compared with donors without HS. Furthermore, significantly more donors with HS were classified as having a moderate depression (3.2% vs 0.7%, P<0.001). Also significantly more with HS were apprenticeship educated, received educational support and sickness or cash benefits.

CONCLUSION: The prevalence of HS in the cohort of blood donors was estimated to 1.8% (Confidence interval 95%: 1.6% - 2.0%). Donors with HS reported characteristics similar to those reported for hospital-based HS patients such as higher BMI, smoking rates and lower socioeconomic status than donors without HS. This article is protected by copyright. All rights reserved.