A pilot study of treatment of striae distensae with variable square pulse Erbium: YAG laser resurfacing

Summary Background Striae distensae ( SD ) are a frequent skin condition for which treatment remains a challenge. Various laser treatments have been employed to remove the epidermis and cause dermal wound and heating with subsequent dermal collagen remodeling. Objective To determine the efficacy and safety of a variable square pulse Erbium: YAG ( VSP Er: YAG ) laser for the treatment of striae in skin phototypes III ‐ IV . Methods Twenty‐one women with SD were treated monthly for 2 months with VSP Er: YAG laser resurfacing using a 7‐mm spot size. One side of their striae was randomly treated with one pass of 400 mJ in short pulse ( SP ) mode with 50% overlapping and one pass of 2.2 J/cm 2 in smooth ( SM ) mode with nonoverlapping. The other side of their striae was treated with two passes of 400 mJ in SP mode with 50% overlapping. Objective and subjective assessments were obtained at baseline and 1‐, 3‐, and 6‐month after treatment. Results In both SP & SM and SP only group, volume of SD measured by Visioscan VC 98 reduced significantly at 6‐month follow‐up visit ( P =.017 and P =.034, respectively). There were no statistically significant differences in skin roughness ( SER ), skin smoothness ( SESM ), and surface measured by Visioscan VC 98. Transient postinflammatory hyperpigmentation ( PIH ) is the common side effect found in patients with darker skin tone even in nonsun exposure areas and can last as long as 6 months. Conclusions VSP Er: YAG laser resurfacing is a promising treatment option for SD . Lower fluence should be used in patients with darker skin phototype to avoid the risk of PIH . In addition, pre‐ and post‐treatment with topical preparations for PIH prevention may be needed.