Abstract
Melasma is a common pigmentary disorder with therapeutic challenges. Laser toning, a repetitive treatment of skin with low fluence 1064-nm Q-switched neodymium:yttrium-aluminium-garnet laser, has been recently used for treatment of melasma in Asia. Its mechanism is based on the subcellular selective photothermolysis theory that low fluence Q-switched neodymium:yttrium-aluminium-garnet laser treatment influences only melanosomes without destroying the melanocytes. No response to treatment, rebound hyperpigmentation or mottled hypopigmentation has been reported during laser toning. Patients with increased vasculature and erythema are poor indicators for laser toning, and history of skin-coloring tattooing should always be determined prior to treatment due to risk of paradoxical darkening. Sensitive skin with erythema should be treated prior to laser toning in order to recover the skin barrier. It is important to use low fluence for laser toning, as high fluence with strong photoacoustic energy will disrupt the basement membrane, further aggravating melasma.
Financial & competing interests disclosure
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
No writing assistance was utilized in the production of this manuscript.
Key issues
• Melasma is a pigmentary disorder that is still difficult to treat.
• Recently, so-called laser toning using low-fluence 1064-nm Q-switched neodymium:yttrium-aluminium-garnet has been used.
• Subcellular selective photothermolysis, which destroys melanosome without destruction of melanocyte is the basic theory for the treatment of melasma with laser toning.
• Laser toning with frequent treatment or strong fluence will result in leucoderma puntate.
• It is better to avoid patients with sensitive skin with disruptive skin barrier and skin-colored tattoo.