Effects of Topical Vitamin K, Vitamin K and Retinol, and Arnica on Post-Laser Bruising

The objective of this study is to assess the comparative utility of topical formulations in hastening the resolution of skin bruising. For each subject, four standard bruises of 7 mm diameter each were created on the bilateral upper inner arms, 5 cm apart, two per arm, using a 595-nm pulsed-dye laser. Randomization was used to assign one topical agent (5% vitamin K, 1% vitamin K and 0.3% retinol, 20% arnica or white petrolatum) to exactly one bruise per subject, which was then treated under occlusion twice a day for 2 weeks. A dermatologist rated bruises in standardized photographs immediately after bruise creation and at week 2.