Development of Striae Distensae - A Mechanochemical Model

Abstract

Striae distensae, otherwise known as stretch marks, are common skin lesions found in a variety of clinical settings. They occur frequently during adolescence or pregnancy when there is rapid tissue expansion, but may also occur in severe weight loss and in corti- costeroid excess. Despite a considerable volume of investigative research, the pathogenesis of striae distensae remains obscure. The interpretation of histologic samples, the major investigative tool, demonstrates an association between dermal lymphocytic inflammation, elastolysis and a scarring response. In this thesis, we investigate the pathogenesis of striae distensae by addressing the coupling between mechanical forces and dermal pathology. We develop a mathematical model for illustrating the effect of fibroblasts and the extracellu- lar matrix in the formation of striae, use linear stability analytical theory to predict the range of parameter values where instability sets in and confirm them using finite difference schemes. We show how a mathematical approach provides a realistic framework that may account for the formation of the stretch marks.