Comparison of Normal Saline Injection with Pneumatic Injector to Subcision for the Treatment of Atrophic Acne Scars.

Acne scarring is a concerning consequence of acne with a prevalence of 11 to 14 percent after acne resolution. Needle subcision is usually used by clinicians to treat acne scars due to its safety and simplicity. Recently, normal saline injection with a pneumatic injector has shown compatible outcomes in treating acne scars. This study compared the effectiveness of acne scar treatment with a pneumatic injector and that of hypodermic needle subcision. Twenty patients with moderate to severe atrophic acne scars were voluntarily enrolled. All consecutive patients were randomly selected and treated with normal saline injection by using a pneumatic injector on one side of the face during three sessions, separated by a four-week interval. The other side of the face was treated with needle subcision at the end of the first week of the protocol. Subjective assessments were performed by self-evaluation and two blinded dermatologists. For objective assessment, the depth and volume of acne scars were estimated by an ultraviolet A light video camera and Vernier calipers at baseline and four, eight, and 12 weeks. Pain score and adverse reactions were also noted at each visit. Eighteen patients with Fitzpatrick Skin Type III or IV completed the study. Differences in the resolution in diameter and the volume of boxcar and rolling acne scars over 12 weeks of follow-up between the pneumatic injection and needle subcision groups were statistically significantly improved relative to at baseline; however, there was no statistically significant difference in the efficacy between the two modalities. Satisfaction with each modality was not statistically different. No serious adverse effects occurred. Minor reactions such as minor hematoma and subcutaneous emphysema resolved within two weeks. The efficacy of normal saline injection with a pneumatic injector is not statistically different from that of needle subcision in treating boxcar and rolling acne scars; however, less side effects were recorded. Given this advantage, the use of pneumatic injectors should be considered for treating acne scars.