A Head-to-Head Comparison of Topical Collagen Powder to Primary Closure for Acute Full-Thickness Punch Biopsy-Induced Human Wounds: An Internally Controlled Pilot Study.

Background: Collagen-based products have been implemented in wound healing due to collagen’s hemostatic properties, low antigenicity, and poor culture ability. Objective: To compare the rate and quality of full-thickness wound healing for topical collagen powder and primary closure. Methods: Eight volunteers received one 4 mm punch biopsy on each thigh. One wound was managed with primary closure while the other received daily collagen powder. Wounds were biopsied at four weeks for histopathological analysis. Subjects rated itch, pain, and treatment preferences at weeks 1, 2, 4, 6, and 12. Results: Six out of eight collagen-treated wounds were completely healed 4 weeks after initial wounding. Histologic analysis of the wounds revealed epidermal re-epithelization in both groups. More organized granulation tissue was noted in collagen-treated wounds and confirmed using Masson trichrome and CD31 staining for collagen and neoangiogenesis, respectively. Subjects reported similar itch and pain metrics between wounds. Both subjects and blinded dermatologists preferred the early cosmetic appearance of collagen-treated wounds over primarily closed wounds. Limitations: Small sample size, absence of negative control. Conclusion: These data suggest that collagen powder is non-inferior to primary closure at the macro- and microscopic levels, while possibly leading to superior early cosmetic outcomes and accelerated histologic wound maturation. Ethics/Clinical Trials Registration: Study was approved by the George Washington University Institutional Review Board (IRB protocol #121745). ClinicalTrials.gov: NCT03481907. J Drugs Dermatol. 2019;18(7):667-673.