Effect of wavelength on cutaneous pigment using pulsed irradiation

History of Lasers in Dermatology

“…The new theoretical understanding of the advantages of pulsed lasers led to a revival of the Q-switched lasers (ruby [30], alexandrite [31], Nd:YAG [32]) for the treatment of benign pigmented cutaneous lesions, especially for tattoo and hair removal [33]. More than 3 decades later, a nearly identical ruby laser to the one used by Goldman in 1963 became the first device approved by the FDA in 1989 for permanent removal of pigmented hair, and the Q-Switched Nd:YAG received FDA approval as a treatment modality for tattoos in 1991 [25,26].…”

Laser Treatment of Pigmented Lesions-2000

“…Pulse durations from 40 to 750 nanoseconds are able to disrupt melanosomes, but longer pulse durations, in the millisecond domain, do not appear to cause specific melanosome damage. 11 Action spectrum studies 12,13 comparing the effectiveness of different laser wavelengths in inducing pigment injury in guinea pig skin have shown similar melanosome alterations but substantial differences in threshold doses and depth of penetration. Shorter wavelengths (Ͻ600 nm) damage pigmented cells with lower energy fluences, while longer wavelengths (Ͼ600 nm) penetrate deeper into the skin but need more energy to induce melanosome disruption.…”

Laser vaccine adjuvants

“…It is well established that skin injury such as scarification or burn can enhance immune responses 40 and lasers can be used to induce such injuries to the skin. 39,[41][42][43] A number of investigators have explored the immune-stimulating effects of thermally-destructive lasers in treating cancer 44,45 and a recent review has been published covering this approach. 46 In addition, fractional laser devices used to enhance delivery of drugs and vaccines have been examined for their ability to alter immunologic responses in the skin to vaccines and immunotherapies.…”

“…35,36 While some clinical trials have suggested that alum-adjuvanted vaccines are tolerable when given intradermally, 37,38 reports of injection-site reactions with intradermally-delivered adjuvanted vaccines are much higher compared with non-adjuvanted formulations. 39 Finally, current adjuvants may not be compatible with intradermal delivery or formulation requirements, especially with newer intradermal vaccination technologies. 33,34 Not surprisingly, there is no adjuvanted intradermal vaccine licensed to date.…”