Evaluation of anisotropic properties of striae distensae with regard to skin surface texture and viscoelasticity

BACKGROUND: Striae distensae (SD) are skin lesions of parallel streaks, which mostly occur during rapid tissue expansion. Considering the etiological mechanism of SD, including dermal network ruptures and alignment to mechanical stretch, structural directionality or anisotropy could be expected. Non-invasive objective methods for measuring the anisotropy of SD have not been suggested yet. Therefore, we evaluated the anisotropic properties of SD with regard to skin surface texture and viscoelasticity, to verify them as new objective evaluation parameters of SD. METHODS: Thirty-two healthy subjects with SD on their body participated. Anisotropy of skin surface texture and biomechanical properties of SD-involved skin and adjacent normal skin was assessed and compared. RESULTS: Analysis of skin surface texture, based on the x60 magnified images, revealed that SD have more disordered patterns compared to the regular honeycomb patterns seen in the normal surrounding skin. SD have bigger sizes of each blob than normal skin. The overall anisotropy of skin texture was significantly higher in SD. Skin biomechanical parameters, measured using Cutiscan((R)) , indicated the less deformable, less recovered, and less viscoelastic properties of SD. When comparing viscoelastic properties over 360 degrees , SD were more anisotropic than the adjacent normal skin as well. CONCLUSION: We observed that SD were significantly more anisotropic than adjacent normal skin with regard to skin surface texture and viscoelasticity. Therefore, anisotropy could be an objective evaluation parameter to represent the distinctive features of SD. It can be applied for evaluation of the SD severity and clinical efficacy of various treatments.