Treatment of redness in rosacea with potassium-titanyl-phosphate (KTP) 532 nm laser with and without topical 1% ivermectin cream: a randomized split-face trial.

Objective: Facial erythema and telangiectasia in rosacea are commonly treated with vascular lasers. Combination with ivermectin 1% cream, may enhance outcomes when combined with laser therapy. This study assesses whether topical ivermectin improves the efficacy of Potassium Titanyl Phosphate (KTP) 532 nm laser for facial erythema in rosacea. Methods: This is a randomized, evaluator-blinded, split-face study. 24 patients with rosacea received four KTP laser sessions; one facial side was additionally treated daily with ivermectin 1% cream. The primary outcome was the change in Normalized Erythema Index (NEI). Secondary measures included Skin Redness Index (SRI), Clinical Erythema Assessment, Physician Global Assessment, telangiectasia score, inflammatory lesion counts, patient satisfaction, and safety. Results: At week 16, the combination side showed a significantly greater NEI reduction than laser alone (ΔNEI%: 16.6 vs 5.3; p = 0.04). No significant differences were observed in SRI, and all other scores. However, papule reduction across visits was significantly greater with ivermectin (p = 0.02). Both treatments were well tolerated, with no serious adverse events. Conclusion: KTP laser effectively reduces erythema and inflammatory lesions; adjunctive ivermectin may further enhance papulopustular lesions. The combination is well tolerated, suggesting a potential adjunctive role for topical ivermectin in laser-based rosacea therapy. clinicalTrials.gov (NCT06033352).