To evaluate the efficacy and safety of a collagen dressing for healing of wounds induced by fractional CO₂ laser in patients with atrophic facial acne scars.

Seventy patients with atrophic facial acne scars were recruited to this study, and randomly divided into a treatment group and a control group. Both the two groups were treated by two sessions of fractional CO₂ laser with an interval of one month. After each session of laser therapy, the treatment group were topically treated with a collagen dressing for 20 minutes once a day for 10 consecutive days, while the control group did not apply any collagen dressing. All the patients were followed for 6 months. Efficacy was evaluated by the degree of acute inflammatory reaction, time needed for crust shedding and patient comfort level. The length of downtime as well as incidence of post-inflammatory hyperpigmentation and other adverse reactions were also assessed.

Compared with the control group, the treatment group showed a decrease in the score for acute inflammatory response（W = 312, P < 0.01）, time needed for crust shedding（t = 2.08, P < 0.05）, incidence rate of post-inflammatory hyperpigmentation（χ² = 6.06, P < 0.05）, length of downtime（t = 3.14, P< 0.05）, but an increase in self-reported comfort level（W = 172, P < 0.01）. No new scar formed in any of these patients.

The collagen dressing is effective in reducing incidence of adverse reactions and improving satisfaction degree of patients with atrophic facial acne scars after fractional CO₂ laser therapy.

Cicatrix; Acneiform eruptions; Lasers, gas; Bandages, hydrocolloid; Collagen