background. Claims have been made suggesting that topical arnica prevents and speeds the resolution of bruises, yet there are no well-designed placebo-controlled studies to date evaluating topical arnica's effect on bruising.

objective. To compare the efficacy of topical arnica in the prevention and resolution of laser-induced bruising.

methods. Nineteen patients with facial telangiectases were enrolled in this randomized, double-blinded, placebo-controlled study and were divided into pretreatment and posttreatment groups. The pretreatment group applied arnica with vehicle to one side of the face and vehicle alone to the other side of the face twice a day for 2 weeks prior to laser treatment. The posttreatment group followed the same procedure for 2 weeks after laser treatment. On day 0, all patients were treated for facial telangiectases using a 585 nm pulsed dye laser. Bruising was assessed using a visual analog scale on days 0, 3, 7, 10, 14, and 17 by the patient and the physician. In addition, photographs taken at each of the follow-up visits were later assessed by a second physician using the visual analog scale.

results. There was no statistically significant difference between the mean scores of arnica and vehicle (P = 0.496) and the mean scores of arnica and vehicle (P = 0.359) in the pretreatment and posttreatment groups, respectively.

conclusion. No significant difference was found between topical arnica and vehicle in the prevention or resolution of bruising.