The Optimal Application of Medium Potency Topical Corticosteroids in Preventing Laser-Induced Inflammatory Responses—An Animal Study

Background: During ablative fractional resurfacing (AFR) laser therapy, thermal damage to the skin is inevitable, resulting in inflammatory responses and small wounds. Corticosteroids are known for their anti-inflammatory effect. However, inappropriate application of corticosteroids carries the risk of delayed wound healing. Therefore, we aimed to find the optimal administration route, timing, and duration of medium potency corticosteroid treatment to prevent AFR laser-induced inflammatory responses and to minimize the risk of delayed wound healing. Methods: We determined the anti-inflammatory efficacy of corticosteroids by skin erythema and tissue biopsies on C57BL/6 mice. Wound healing was evaluated by crust area and epithelial gap. Finally, Masson’s trichrome stain and α-SMA immunohistochemistry stain were used to analyze scar contracture. Results: Our results demonstrated that one dose of medium-potency topical corticosteroid applied immediately after AFR laser treatment could prevent erythema effectively with minimal disruption to wound healing. Notably, when more than one dose was administered, wound healing was delayed and scar contracture was aggravated by the application of medium-potency topical corticosteroids in a dosage-dependent manner. Conclusion: Our findings suggested that single-dose medium-potency topical corticosteroids could potentially improve AFR laser-induced acute inflammatory responses in clinical applications.

Emerging Technologies in Scar Management: Laser-Assisted Delivery of Therapeutic Agents

Topical application of medications is difficult through intact skin due to physiological barrier of stratum corneum. Effective transdermal drug delivery system can offer distinct advantages over the topical application and oral administration of drugs. Laser systems have showed clinical benefits for patients in various types of scars for decades. In particular, the advent of fractional resurfacing advanced laser has enhanced the scar treatments dramatically. A fractional laser irradiates cells with high precision by controlling the area and degree of ablation through laser settings. In addition to local thermal destruction and stimulation, fractionated devices may also play an important role in drug delivery through the skin. Preclinical studies substantiate enhanced drug accumulation for a variety of topically applied drugs after ablative fractional laser therapy. Laser-assisted drug delivery is an evolving technology with potentially broad clinical applications. Multiple studies demonstrate that laser pretreatment of the skin can increase the permeability and depth of penetration of topically applied drug molecules. We discuss the mechanisms of laser-assisted drug delivery for scar treatment to enhance our understanding of this evolving technology and suggest optimal protocols of treatment.