Adverse events of fractionated carbon dioxide laser: review of 373 treatments.

OBJECTIVE: To determine the frequency and classification of adverse events (AEs) associated with fractionated carbon dioxide (CO₂) laser treatment.
METHODS: A retrospective evaluation of 373 successive fractionated 10,600-nm CO₂ laser treatments in 287 patients conducted in a single center. AEs of laser therapy, including onset, duration, and treatment, were identified and analyzed through chart review, telephone calls, and email.
RESULTS: Three hundred seventy-three treatments resulted in 47 AEs (12.6%) in 40 patients (13.9%). The most frequent AEs were allergic or contact dermatitis (4.6%) acneiform breakout (3.5%), prolonged erythema (1.1%), and herpes simplex virus outbreaks (1.1%). AEs were distributed across different ages, skin types (95% Type II, III, 5% Type IV), and laser parameters. Three of 22 patients (13.6%) with two body areas treated simultaneously and six of 16 patients (37.5%) with three body areas treated simultaneously experienced AEs. Because of the multiple areas treated, some patients experienced multiple AEs. Six AEs were documented in the three patients who underwent two concurrent treatments, and a total of nine AEs were documented in six patients who underwent three concurrent treatments. The 24 patients who had subsequent additional treatments had three documented AEs (12.5%).
CONCLUSION: CO₂ fractionated laser skin treatment is associated with a relatively low complication rate when one body location is treated, but the complication rate increases with three concurrent treatments of multiple body locations. Subsequent treatments of the same body location after a healing period of 1 to 6 months resulted in no greater risk of AEs.