임상 논문

Riehl's melanosis is a hyperpigmentation disorder that has a significant psychological and social impact on individuals. In the past 10 years, new categories have been developed, raising questions about how to classify Riehl's melanosis. The mechanism of this disease remains unclear, although the type IV hypersensitivity response caused by allergic sensitization, as well as genetic, ultraviolet radiation, and autoimmune factors, is to blame. Clinical manifestation, dermoscopy, reflectance confocal microscopy, patch/photopatch testing, histopathology, and a novel multimodality skin imaging system have been used for the diagnosis. A variety of therapies including topical skin-lightening agents, oral tranexamic acid, glycyrrhizin compound, chemical peels, and lasers and light therapies (intense pulsed light, 1064-nm Q-Switched Nd: YAG laser, 755-nm PicoWay laser, nonablative 1927-nm fractional thulium fiber laser, new pulsed-type microneedling radiofrequency), with improved effectiveness. The latest findings on possible biomarkers and their relationship to other autoimmune diseases were also summarized. Until recently, quality-switched nanosecond lasers have been the workhorse lasers in treating pigmented lesions. However, the recently commercialized picosecond lasers have provided physicians with a novel method to manage pigmented lesions. Most recently, the first picosecond laser with a 730-nm wavelength was developed to specifically target melanin and melanocytes. We report on two Asian patients with freckles, lentigines, and melasma who were successfully treated with a novel 730-nm Ti:Sapphire picosecond laser (Picoway®; Syneron Candela, Corp). The clinical outcome was measured by the global percent of clearance, which was evaluated by blinded observers by comparing the post-treatment photographs with the baseline photographs. In both patients, a significant pigmentary reduction was achieved with only one treatment session. In both patients, the treatments were well tolerated with minimal discomfort even without topical anesthesia. No post-inflammatory hyperpigmentation or repigmentation was observed until the 6-week follow-up. The pigmentary conditions treated included freckles, lentigines, and melasma. Both subjects showed clinical improvement, with the best results observed for the treatment of freckles such that 95% of the lesions achieved excellent response (75-94% lightening). The results of this case report indicate that a novel 730-nm Ti:Sapphire picosecond laser may be effective and safe in treating pigmentary disorders in darker-skinned patients. Therefore, further well-designed, prospective clinical trials are warranted to establish the potential of 730-nm picosecond lasers and determine the optimal treatment parameters in comparison to existing laser and light modalities. Lasers Surg. Med. © 2020 Wiley Periodicals LLC. Pigmentation is one of the few major characteristics according to which scars are evaluated. Data on the treatment of the hyperpigmented component of scars are sparse. The authors aimed at evaluating the efficacy of the fractional 1,064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) picosecond laser in the treatment of the hyperpigmented component of scars. Sixteen patients with hyperpigmented scars underwent 3 to 8 treatment sessions at 3- to 6-week intervals with the 1,064-nm Nd:YAG picosecond laser (PicoWay, Candela, Resolve handpiece). The treatment response was evaluated by 2 noninvolved dermatologists on a global assessment scale (GAS) of 1 to 4. A Mexameter quantitatively evaluated the melanin content of the scar before and after laser treatments. The average GAS score of the 2 noninvolved dermatologists was 3.31 ± 0.57. The patients assessed their level of tolerance as good or excellent and their satisfaction level as moderate or high. The Mexameter showed that the melanin index decreased considerably (by 39.11 ± 11.58%) in all patients after treatment. The fractionated nonablative picosecond Nd:YAG laser was effective for the treatment of the hyperpigmented component of scars.