308‐nm Excimer Light for Inflammatory Acne in Pregnancy: A Prospective Pilot Study

Abstract

BACKGROUND/PURPOSE: Concerns about fetal safety limit acne treatments during pregnancy. The 308-nm excimer light offers targeted UVB exposure to lesions with less impact on healthy skin compared to whole-body NB-UVB. We assessed the efficacy and safety of lesion-directed excimer light for inflammatory acne in pregnancy, including folate monitoring and obstetric outcomes. METHODS: This single-center, single-arm pilot study was conducted in 13 pregnant women with inflammatory acne in the second trimester. Lesion-directed 308-nm excimer light was delivered to facial lesions twice weekly for 8 weeks with erythema-guided escalation; serum folate was monitored, and obstetric outcomes were captured prospectively. For assessment of improvement, the Investigator's Global Assessment (IGA) and the Dermatology Life Quality Index (DLQI) were applied. Analyses emphasized estimation with 95% CIs; exploratory patient-reported/assessor correlations used Spearman's ρ with exact p-values. RESULTS: Both inflammatory and non-inflammatory lesions improved; the primary endpoint showed a 48.3% mean reduction in inflammatory lesions at Week 8, 5/13 achieved a ≥ 2-grade IGA improvement, and mean DLQI improved by 5.9 points. Serum folate remained within the reference range, and obstetric outcomes were reassuring. CONCLUSION: Excimer light was associated with clinically meaningful reductions in inflammatory acne lesions with reassuring safety signals and obstetric outcomes. It may be a pregnancy-compatible option when other therapies are limited and merits evaluation in controlled trials.