Q-switched frequency-doubled Nd:YAG (532 nm) laser versus trichloroacetic acid 35 peeling in the treatment of dorsal hand solar lentigo: An assessor-blind split-hand randomized controlled trial

Abstract

Background Solar lentigo (SL) is a benign hyperpigmented spot occurring due to ultraviolet exposure, most commonly in the elderly. We aimed to compare the safety and efficacy of trichloroacetic acid (TCA) peeling with Q-switched laser in the treatment of SLs. Methods This assessor-blind split-hand randomized controlled trial included 45 patients with symmetric SLs on the back of their hands referred to the dermatology clinics from March 1 to June 24, 2021. TCA 35 was applied to the back of one hand, and the contralateral hand received Q-switched laser. The interventions were repeated for a total of three sessions 4 weeks apart. Eight weeks after the last treatment session, lesion lightening was graded from 1 to 4. Patient satisfaction with treatment was assessed using a visual analogue scale (VAS). Adverse events were also noted. Results Of the 45 patients included in the current study with a mean age of 52.71 +/- 9.73 years, 11 (24.4) were male. The Fitzpatrick skin type was II in 11 patients (24.4), III in 23 (51.1), and IV in 11 (24.4). Lesion lightening and patient satisfaction were both significantly better with Q-switched laser compared to TCA peeling (standardized mean difference SMD = -1.25, 95% confidence interval CI -1.69; -0.79, p < 0.001 and SMD = -1.12, 95% CI -1.56; -0.67, p < 0.001, respectively). Overall, post-inflammatory hyperpigmentation (PIH) occurred in one patient in the laser group and for in the TCA group. Also, erythema and pruritus were observed in all patients of both groups after intervention which were treated with topical repair cream. Conclusions Q-switched laser was superior to TCA peeling for the treatment of SLs in terms of lesion lightening and patient satisfaction with a large effect.