Abstract
Q-switched (QS) Nd:YAG 532-nm laser is among the most effective treatment options for solar lentigines. However, a high incidence of postinflammatory hyperpigmentation (PIH) has been reported. The available evidence on PIH prophylaxis is currently sparse and controversial. Therefore, we aimed to determine the efficacy of multiple prophylactic treatments for PIH, including topical corticosteroids, topical corticosteroids under occlusion, and topical brimonidine, in reducing the incidence of PIH following QS laser treatment of solar lentigines. Thirty-eight subjects with at least 8 solar lentigines on their forearms were recruited to receive QS Nd:YAG 532 nm laser treatment. The treatment areas on the forearms were divided into 4 areas: left upper, left lower, right upper, and right lower forearm. The lesions in each area were randomly allocated to receive different PIH prophylactic agents after laser treatment: topical clobetasol for 2 days, topical clobetasol under occlusion in single application, topical brimonidine for 3 days, or petrolatum jelly (control). The occurrence and intensity of PIH, degree of erythema, improvement of lesions, and adverse reactions were evaluated at 2, 4, 8, and 12 weeks. Patient satisfaction was assessed at the end of the study. No statistically significant differences were detected between the groups regarding the occurrence of PIH, the intensity of PIH, or the improvement of lesions. However, the incidence of posttreatment erythema was significantly lower in the lesions that received topical clobetasol and topical clobetasol under occlusion, compared to the control group, at all visits. Additionally, patient satisfaction was significantly greater with topical clobetasol and clobetasol under occlusion. Topical brimonidine had the highest side effects on itching, dryness, and eczema. In conclusion, topical clobetasol and brimonidine were not found to be significantly effective at reducing the incidence of PIH after laser treatment, but topical clobetasol and topical clobetasol under occlusion significantly increased patient satisfaction after laser treatment.