Pulsed dye laser vs. photodynamic therapy in the treatment of refractory nail psoriasis: a comparative pilot study.

Background: Nail psoriasis is often refractory to traditional treatments, and patients with nail psoriasis usually demand a therapeutic option. Both photodynamic therapy (PDT) and pulse dye laser (PDL) have proved effective for plaque-type psoriasis, but they have not been evaluated in nail psoriasis. On the other hand, delta-aminolaevulinic acic has been shown to penetrate into the nail matrix and nail bed occluded with bioadhesive patches.

Objectives: To compare the efficacy of PDT and PDL in the treatment of nail psoriasis.

Methods: We studied 61 nails treated with PDT and 60 nails treated with PDL in a group of 14 patients. The PDT used PDL as the light source. Sessions were applied monthly treating one hand with PDT and the other with PDL. The hand treated with PDT was occluded with methyl-aminolaevulinic acic (MAL, Metvix) for 3 h using a bioadhesive patch. The nails treated were evaluated at baseline, and after 3 and 6 months according to the Nail Psoriasis Severity Index (NAPSI) score.

Results: A decrease in NAPSI score was observed with both treatments and in both nail matrix and nail bed involvement. No statistical differences were found between PDT and PDL (P = 0.632, P = 0.084, P = 0.535, at baseline, and 3 and 6 months, respectively), and between nail matrix and nail bed NAPSI scores (P = 0.423 and P = 0.853, respectively). The subjective impression of the patients was good, especially regarding the decrease in the pain.

Conclusions: PDL seems to be effective in the treatment of nail psoriasis and improves nail matrix and nail bed involvement. MAL does not seem to play role in the clinical response.