Fractional CO2 laser for the treatment of acne scars

Background Numerous reports have been published on skin rejuvenation by the so‐called fractional laser device that delivers a laser beam in a dot form over a grid pattern. Aims In this study, we characterized the effects of a fractional CO₂ laser on atrophic acne scars at the clinical and ultrastructural levels. Methods Seven healthy adult Japanese volunteers (aged 32–46 years, mean 37.6, five men and two women of Fitzpatrick skin type III) were recruited for this study. A fractional CO₂ laser device, SmartXide DOT (DEKA, Florence, Italy), was used with irradiation parameters set as follows: output power 10 W, pulse width 600 μs, dot spacing 800 μm, and stack 2 (irradiation output power 0.91 J/cm²). A clinical examination and punch biopsy of each subject was performed before and just after the irradiation, and also at week 3 after three irradiation sessions. The biopsy specimens were stained with toluidine blue and were examined ultrastructurally. Results Clinical improvement of the atrophic acne scars was observed at week 3 after the third irradiation session in all cases compared with the condition before treatment. Histologically, outgrowths of many degenerated elastic fibers were observed as irregular rod‐shaped masses in the superficial dermis prior to the treatment in the region of the acne scars. At week 3 after the third irradiation, the degenerated elastic fibers were no longer observed, and the elastic fibers were elaunin‐like. Conclusions The fractional CO₂ laser is considered to be very effective for treating atrophic acne scars.