Efficacy of Long-Pulsed 755-nm GentleLASE Alexandrite Laser for Epidermal Pigmentary Lesions in Skin Types III-V

Abstract

Background: Epidermal pigmentary lesions, including freckles, senile lentigines, solar keratosis, and melasma, are common cosmetic concerns with variable responses to available treatment modalities. The long-pulsed 755 nm alexandrite laser may provide effective clearance while improving overall skin appearance.

Objective: To evaluate the efficacy of the long-pulsed GentleLASE alexandrite laser in treating epidermal pigmentary lesions in patients with skin types III to V.

Methods: This prospective, single-arm interventional study included 20 patients aged 18 to 66 years. Patients were recruited and treated from January to March 2026 at the Lahore branch of the American Laser of Cosmetic Dermatology. The study included 10 patients with freckles, four with senile lentigines/solar keratosis, and six with melasma. The entire face was initially treated using a 12-mm spot size at 12 - 16 J/cm² with dynamic cooling, followed by targeted lesion treatment at 16 - 20 J/cm² without dynamic cooling. Each patient was followed for three months, with assessments at one, two, and three months. Clinical improvement, patient satisfaction, adverse effects, photographs, and lesion clearance were assessed.

Results: Freckles showed 60 to 80% lesion clearance after one treatment session. Senile lentigines and solar keratosis demonstrated 80 to 100% clearance following a single treatment. Among six patients with melasma, four showed improvement despite previous resistance to other treatment modalities, whereas two showed no improvement. None of the melasma patients experienced worsening after treatment.

Conclusion: Long-pulsed GentleLASE alexandrite laser treatment produced substantial improvement in epidermal pigmentary lesions, particularly freckles, senile lentigines, and solar keratosis, with benefits often evident after a single session. Entire-face treatment followed by targeted regional treatment may additionally improve skin texture, translucency, and pores while maintaining patient satisfaction and avoiding occlusive dressings in selected patients with skin types III–V.