Low and high body mass index in hidradenitis suppurativa patients-different subtypes?

Introduction Overweight is a well established risk factor for Hidradenitis Suppurativa (HS). In this cross sectional study, we compare HS patients with a high body mass index (BMI) with HS patients with a low BMI to investigate differences in disease characteristics. Materials and method Patients were recruited from 17 dermatological centers from 4 continents. A total of 246 patients with a BMI below 25 were compared to 205 patients with a BMI of above 35. Results Patients with a high BMI suffered more severe disease (Hurley, physician global assessment, number of areas affected and patient reported severity, p < 0.001 for all). There was no difference in smoking (p = 0.783) nor in family history (p = 0.088). In both low and high BMI patients, early onset of HS was a predictor of positive family history (p < 0.001, for each). For low BMI patients, an increase in BMI significantly increased patient reported severity (p < 0.001). For patients with a high BMI, number of pack years significantly increased patient reported severity (p = 0.001). Cluster analysis of eruption patterns were location specific for low BMI patients but severity specific for high BMI patients. Discussion Patients with a low and high body mass index could represent two clinically different subtypes. We suggest a non-linear relationship between BMI and impact of HS. As patients go from a low BMI patient to a high BMI patient (or from high to low), eruption patterns and risk factors may change. This article is protected by copyright. All rights reserved.