A retrospective analysis of the management of freckles and lentigines using four different pigment lasers on Asian skin

Background : The risk of post-inflammatory hyperpigmentation (PIH) is increased during freckles and lentigines treatment in Asians. Objective : To determine the effectiveness and safety of using 595-nm long pulsed dye laser (LPDL), 755-nm LP Alexandrite laser, 532-nm QS Nd:YAG laser and 532-nm LP potassium-titanyl-phosphate (KTP) laser for the treatment of freckles or lentigines in Asian patients. Methods : This is a retrospective study of 40 Chinese patients, who were divided into four groups based on treatment modality using four different pigment lasers. Each patient attended between 1 and 4 treatments (mean of 1.8), at 4-6 weeks intervals, depending on clinical response. Lesional clearance and PIH were assessed by two independent clinicians. Results : Statistically significant improvement of global and focal facial pigmentation was found after treatment with LPDL, QS Nd: YAG and LP KTP lasers. No significant improvement was found after LP Alexandrite laser. PIH risk was 20% after LP Alexandrite treatment, 10% with QS Nd: YAG, and absent after LPDL and LP KTP treatment. Conclusion : A long pulse laser and small spot size appear to reduce the risks of lentigines treatment in darker skin types.