The mechanical stress in skin folds as an explanation of the location of hidradenitis suppurativa lesions

Background: It is suspected that mechanical stress of intertriginous areas contributes to Hidradenitis suppurativa (HS) pathophysiology. This presupposes that mechanical stress is greater in the skin folds. Little is however known of the mechanical stresses of the regions that form part of the definition of HS. It is hypothesized that both folds and total skin (including subcutis) thickness play a role in the mechanics of skin folds.

Objectives/Methods: In order to gain a better understanding of mechanical stress of intertriginous areas, a mathematical model was created to investigate the influence of subcutis and dermis thickness, as well as the crease depth on the mechanical stress. We studied the mechanical stress induced by the creation of skin creases in a parametric study of these quantities.

Results: The model suggests that for large subcutis thicknesses and deep skin creases significant fractions of the epidermis experience large stresses, whereas this is not the case when the subcutis becomes relatively thinner.

Conclusion: The theoretical finding provides a background for the role of obesity in HS pathophysiology, and it supports a role for mechanical stress in the pathogenesis of HS.