Nail diseases are an important component of any dermatologist's practice. In many cases, treatment of nail conditions is difficult, as penetration of topical medications through the nail plate is challenging. Light therapy, which is able to travel through tissues and focus on specific targets without damage to surrounding normal skin or nail, would be a welcome option in the therapy of any nail disorder.
The excimer (308 nm) laser is already widely used for the treatment of skin psoriasis, with excellent results. Penetrating the nail plate to reach active disease has been challenging with this laser, however. Lasers and light devices have been shown to be effective in the treatment of psoriasis vulgaris, but the data for nails is scant.
Aminolevulinic acid under occlusion has been able to penetrate and affect the nail plate, suggesting that photodynamic therapy (PDT) may be an option for treatment of nail disorders. In one pilot study, however, PDT using methyl aminolevulinic acid activated by pulsed dye laser (PDL) was no more effective than using PDL alone (Fernandez-Guarino M, et al. J Eur Acad Dermatol Venereol. 2009 Aug;23(8):891-895). The same study found that monthly pulsed dye laser treatments led to a statistically significant decrease in the nail psoriasis severity index score (NAPSI) after six months.
Histologic examination of psoriasis vulgaris before and after treatment with PDL has shown significant reductions in vascular endothelial growth factor receptors (VEGFR) and TNF-alpha, an effect possibly responsible for the reduction in lesion severity.
Oram et al also examined the effects of the pulsed dye laser for nail psoriasis (Oram, et al. Dermatol Surg. 2010 March;36(3):377-381). Researchers treated nails once a month for three sessions with a long pulsed dye laser (595 nm at 8-10 J/cm2 and 1.5 ms). They found a statistically significant improvement in NAPSI scores in treated nails. To date, PDL seems to be the leading laser therapy for nail psoriasis. Controlled trials are needed to determine best treatment settings using PDL, but this offers a viable option for psoriatic disease of the nails.
Lasers have also been used for periungual diseases, such as verrucae, periungual fibromas, digital mucous cysts and ingrown nails. The CO2 for partial matricectomy has been effective and easy to perform.