Efficacy And Safety Assessments Of Low-fluence Q-Switched 1064-nm Neodymium-doped Yttrium Aluminum Garnet Laser For The Treatment Of Facial Freckles

Background:Freckles is a common cutaneous pigmented disease,and is affected by sunlight.Freckles occur not only in 4-5 year's old,but also in early adolescence.Freckles become equally distributed in the face and other sun-exposed areas,which obviously had impact on the situation of patients with self-evaluation,social relations and quality of life.Histopathology findings reveal the epidermal hypermelanosis without an increase in melanocyte numbers.Solar irradiation may exacerbate the production of melanin.The traditional cryotherapy,532-nm Q-switched potassium-titanyl-phosphate laser(QS KTP)and intense pulsed light(IPL)have been used in the treatment of freckles,which iduce the skin crusting or purpura,increasing the risk of post-inflammatory hyperpigmentation(PIH),and need down time as long as 7 days.Clinically,the treatment modality with good results and no down time is required by patients and doctors..In 2008,the Korean researcher first proposed low-fluence large sport size 1064-nm QS Nd:YAG laser modality for the treatment of melasma,and this modality could significantly lighten the pigmentation and need no down time.As freckles are also epidermal cutaneous skin pigmentation,we proposed the low-flence large spot size 1064 nm QSNY laser treaatment modality will work in the intervention of freckles.Objective:To determine the effectiveness and safety of low-fluence 1064-nm Q-switched neodymiumdoped yttrium aluminum garnet(QSNY)laser treatment of facial freckles.Methods:Fifteen adult patients with facial freckles who received treatments with low-fluence large sport size 1064-nm QSNY laser were recruited from the freckles clinic of Shandong Provincial Hospital of Dermatology &Venereology from February,2013 to April 2016.After written informed consent,the patients received treatments at 2-3 weeks intervals for 3-5 times,the laser settings were 1064 nm wavelength,7mm spot size,1.5-2.5J/cm2 fluence.The patients were then followed up for 6 months after treatments.All the before and after pictures were evaluated by two dependent dermatologists and the patients self evaluation were also recorded.Results:Eight of fifteen patients had achieved excellent improvement(76–100%)at the end of treatment,and 4 of 15 patients had good improvement(51–75%).The remaining 20% had modest effects.In patient self-evaluation of the degree of improvement of freckles,nine(60%)assessed it as very much to much improved(76–100%),and six(40%)assessed it as moderate(51–75%).All the cases enrolled reported minor erythema which only lasted for several hours,and had no influence for the next day's work.Conclusion:Low-fluence large sport size 1064-nm QSNY laser treatment is a safe procedure for the treatment of facial freckles which showed improvement with no significant side effects and no down time.