This laser remains the most rapid and effective technique for removing facial spots or pigments. It involves pumping laser energy within an extremely short instant (Q-switch mode) at an appropriate wavelength (500–700mm) that can be easily absorbed by melanin, which shatters the highly aggregated melanin spots via its micro-explosion property before being metabolized and cleaned by the macrophagocytes, thus achieving the purpose of lightening black spots or removing pigments. Generally, this spot removal laser requires high energy and leads to temporary skin wounds after the operation that takes approximately 5–7 days of recovery time to scar and shed. Besides, ultraviolet injury should also be avoided during treatment to prevent unexpected pigmentation or darkening and other sequelae, which also constitutes the biggest difference with pulsed light spot removal. As long as patients fully understand the characteristics and risks of laser treatment before the operation and cooperate with postoperative wound caring, they can attain rapid and distinct improvement.
Black spots are formed due to numerous causes such as congenital genetic makeup, ultraviolet injury, skin metabolic disorder, hormonal stimulus, exposure to chemicals, chronic inflammation, or even lifestyle and smoking, which all lead to unexplained spots or pigmentation. Moreover, as black spots from numerous patients arise from years of accumulation and numerous spots of different natures coexist, this increases the complexity and number of laser treatments. Our clinic offers the Q-switch mode Nd:YAG laser, which has double wavelengths, and can be used for treating various common skin spots and pigments.
A wavelength of 532 nm can be used for the treatment of superficial spots or pigments, such as freckles, sunburns, or aging spots, which are cleansed by approximately 1-2 treatments, once every 6–8 weeks. There is a scarring period of 5–7 days after the operation, and patients should care for wounds and apply sunscreen to prevent secondary melanin aggregation or recurrence. If patients are unable to accept the wound and recovery time of this treatment, they can also opt for pulsed light spot removal, which has no constraint of recovery time, and achieves similar results by approximately 3-4 treatments.
A wavelength of 1064 nm is primarily used for the treatment of relatively deep spots or pigmented patches such as epidermal nevus, chloasma hepaticum, Nevus of Ota, nevus zygomaticus, and tattoos. Because such black spots are the result of melanin aggregation at the dermal layer, its treatment not only entails a high-energy laser but also mostly necessitates 3–6 repeated treatments (once every 6–8 weeks) to attain stable and distinct improvements. Nevertheless, along with the accumulation of laser energy and number of lasings, injuries to peripheral skin tissues also aggravate, leading to a relatively high incidence of postoperative darkening or pigmentation. Therefore, patients should pay more attention to applying sunscreen during treatment.
Despite employing appropriate laser energies and wavelengths employed for the treatment of various skin spots, the results may still differ in light of the primary spot characteristics or individual skin conditions. In particular, for large area pigmentations such as chloasma hepaticum and nevus zygomaticus, the results of laser treatments are predominantly slow to show or are insignificant. Patients should patiently cooperate with the lasing at separate times or different sites and should not be too hasty to incur re-darkening. Even in case of darkening or pigmentation during treatment, patients should not be too anxious as the original skin color can be restored after skin repair and treatment with topical drugs for 3–6 months.