Comparison between the efficacy of Intense Pulsed Light (I.P.L.) versus Photo-Dynamic Therapy (P.D.T.) with methylene-blue in the treatment of psoriatic nails.

Background: Nail affection is seen in up to 50 % of patients with skin psoriasis, although up to 5% of nail psoriatic patients do not complain of skin affection. Various treatment options are emerging for nail psoriasis such as intense pulsed light Tawfik, 2014). Methylene-blue (M.B) is a phenothiazine dye which is suggested to mediate cell cyto-toxicity by the generation of hydroxyl-radicals which change the intra-cellular calcium homeo-static mechanisms (Lee and Wurster, 1995).

Objective: Evaluation and comparing the efficacy of I.P.L. and methylene-blue assisted photo-dynamic therapy for treating psoriatic nails.

Methods: 20 patients with mild to moderate psoriasis with nail involvement. Sessions were performed once every 2 weeks on all the affected nails for a maximum of 3 months (6 sessions). Nail Psoriasis Severity Index (N.A.P.S.I.) score and photo-documentation were done for all the patients to assess the nail status at the first visit, after two, six sessions and three months after finishing the six session (0 m., 1 m., 3 m. and 6 m.). Nails of the right hand were treated with methylene-blue mediated photo-dynamic therapy using the Intense Pulsed Light (IPL) as the light source, while the left hand received conventional IPL (430-1200 nm) alone.

Results: The present study showed that both treatments were effective on nail psoriasis, but MB-PDT was more effective in nail-bed lesions. There was no significant difference regarding patient satisfaction.

Conclusions: Both Intense Pulsed Light and methylene-blue assisted photo-dynamic therapy were safe, nearly pain-free, easy to use, and effective for treating nail psoriasis. MB-PDT is a new promising strategy for the treatment of nail psoriasis.