The Principles of 308 Excimer Laser Treatment

1.Stimulate melanocyte proliferation, promote melanin production
2.Induce the death of T cell
3.Promotes vitamin D3 production
4.Activate the pseudocatalase

308 nm excimer laser for the treatment of vitiligo is related to the mechanism of T cell apoptosis. 308 nm excimer laser can induce the apoptosis of activated T cells in vitiligo lesions. So that the skin lesions not only disappear completely at the naked eye, but also return to normal tissue structure at the microscopic level after irradiation. Its effect is obvious, which is more significant than that of narrow-band ultraviolet.

Vitiligo is characterized by selective destruction of melanocytes, which may be associated with an autoimmune response. Narrow spectrum ultraviolet rays (NB-UVB) may have an immunomodulatory effect on cell and autohumoral immunity, which can stabilize the depigmentation process.

In addition, Narrow spectrum ultraviolet rays (NB-UVB) is widely recognized to have similar effects to PUVA (Psoralen Ultraviolet A) in stimulating the accumulation of residual melanocytes to the outer root sheath of the peripheral hair follicle.

Melanocyte mitosis, melanin production and migration are often induced by various cytokines and inflammatory mediators, including interleukin 1, tumor necrosis factor ɑ, and leukotriene C4. Recent studies have shown that various cytokines and inflammatory mediators are increased after UVB irradiation, suggesting that this is one of the mechanisms by which UVB induces pigment recovery.