Color‐Guided Long‐Pulsed 532/1064‐nm
KTP
/Nd:
YAG
Laser for Post‐Acne Erythema: A Real‐World Study
Jiayi Jiang, Ying Yang, Xiaoqing Wang, Jingwen Jiang, Yan Tang, Bingrong Zhou ABSTRACT
Purpose
Post‐acne erythema (PAE) is a common sequela of inflammatory acne. Pulsed dye laser is effective for vascular erythema but is associated with purpura and downtime. This study evaluated the real‐world effectiveness and tolerability of a standardized, color‐guided long‐pulsed 532/1064‐nm KTP/Nd:YAG protocol for PAE.
Methods
This single‐center retrospective cohort study screened 147 patients and included 136 eligible patients. All patients completed three sessions at 4‐week intervals. Each session comprised low‐fluence full‐face 532‐nm KTP scanning followed by lesion‐targeted treatment: 532‐nm KTP for pink‐to‐red lesions and 1064‐nm Nd:YAG for violaceous lesions, with both wavelengths used when both color patterns were present. Outcomes included an adapted CAT score, erythematous area percentage, Investigator Global Assessment, satisfaction, pain, 6‐month quantitative stability, clinical worsening, and adverse events.
Results
The median CAT score decreased from 5 to 1, and the median erythematous area percentage decreased from 4.50% to 1.00% (both p < 0.001). Median CAT improvement rates were 58.34%, 84.52%, and 87.50% in low‐, intermediate‐, and high‐severity groups, respectively; the between‐group difference was not significant ( p = 0.10). All patients in this cohort achieved at least 25% improvement on Investigator Global Assessment. Satisfaction was 97.79%, and the median pain score was 2/10. Transient erythema resolved within 1–3 days. One patient (0.74%) developed purpura with a small blister; no pigmentary sequelae or scarring occurred. At 6 months, CAT score and erythematous area percentage remained comparable with the 1‐month posttreatment values in the overall cohort ( p = 0.285 and p = 0.346, respectively) and across baseline severity subgroups (all p > 0.05).
Conclusion
These findings suggest that a standardized three‐session, color‐guided long‐pulsed 532/1064‐nm KTP/Nd:YAG protocol may be an effective and well‐tolerated option for PAE, with exploratory 6‐month quantitative stability, warranting confirmation in prospective controlled studies.