Low-fluence Q-switched Nd:YAG 1064-nm laser versus Q-switched Nd:YAG 532-nm laser in the treatment of hyperpigmented lips: a prospective, randomized, controlled, evaluator-blinded trial

Lip hyperpigmentation is an esthetic problem. Clinical data from controlled comparative studies is insufficient to support the efficacy of laser treatments for hyperpigmented lips. This study is aimed to compare the efficacy of low-fluence Q-switched Nd:YAG 1064-nm laser (LFQS 1064-nm) versus Q-switched Nd:YAG 532-nm laser (QS 532-nm) for the treatment of hyperpigmented lips. A randomized, controlled, evaluator-blinded study was conducted in thirty subjects. They were randomized into 2 groups. The first group was treated with five treatment sessions with a 2-week interval of LFQS 1064-nm laser while the second group was treated with a single session of QS 532-nm laser. The evaluation was conducted at baseline, 2 weeks of each post treatment, and 4 weeks after the last treatment session. The efficacy was assessed by melanin index, Methuen colored plate, photographic evaluation, pain score, patient’s satisfaction, and patient’s Dermatology Life Quality Index. The adverse effects were also recorded. All patients attained throughout the study protocol. The most frequent fluence applied was 2.4 J/cm² (2.2–2.5 J/cm²) and 2.0 J/cm² (1.7–2.4 J/cm²) in the LFQS 1064-nm group and QS 532-nm group, respectively. The results of the QS 532-nm group showed greater percentage of melanin index reduction and better average mean of photographic evaluation percentage changes from the baseline than the LFQS 1064-nm group (p < 0.001 and p < 0.001, respectively). The adverse effects were less likely to occur in the LFQS 1064-nm group. Few cases of scale, hypopigmentation, bleb formation, postinflammatory hyperpigmentation, and labial edema occurred only in the QS 532-nm group.