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Reduction of treatment frequency and UVA dose does not substantially compromise the antipsoriatic effect of oral psoralen-UVA

https://doi.org/10.1016/j.jaad.2004.04.029Get rights and content

Abstract

Background

The carcinogenic potential of 8-methoxypsoralen photochemotherapy (psoralen-UVA [PUVA]) is correlated with the total number of treatments and cumulative UVA dose applied during oral PUVA therapy.

Objective

We sought to determine whether reducing treatment frequency and UVA dose affects the therapeutic efficacy of oral PUVA for patients with chronic plaque psoriasis.

Methods

This was a prospective, randomized, half-side study performed in a photodermatology department in a dermatology hospital. Eighteen consecutive patients with chronic plaque psoriasis received paired PUVA regimens (0.5 minimal phototoxic dose [MPD] 4 times/wk vs 1 MPD twice/wk, 0.5 MPD twice/wk vs 1 MPD twice/wk, and 0.5 MPD twice/wk vs 0.75 MPD twice/wk). The PUVA regimens were assessed for reduction of Psoriasis Area and Severity Index (PASI) score and the number of treatments and cumulative UVA dose required to reduce PASI score to defined end points (ie, PASI reductions of 25%, 50%, and 75%) or to induce complete remission (PASI < 3).

Results

Reducing the number of treatments while maintaining the same UVA dose per week did not reduce overall therapeutic efficacy. Reducing the number of treatments to twice a week and reducing the UVA dose from 1 MPD to 0.75 or 0.5 MPD per treatment only slightly affected intermediate therapeutic efficacy (between the second and seventh weeks of therapy) but had no effect on final clearance rates. The time to complete clearance did not significantly differ between regimens. The mean cumulative UVA dose was significantly lower for the least intensive dose regimen (0.5 MPD twice/wk) than for the more intensive regimens.

Conclusions

Reducing treatment frequency and UVA dose does not substantially compromise the therapeutic efficacy of PUVA.

Section snippets

Study design and participants

Our study was a prospective randomized trial of paired PUVA regimens compared bilaterally in individual patients. Participants included 18 patients (14 male and 4 female) treated for chronic plaque-type psoriasis (Psoriasis Area and Severity Index [PASI] >10) at our institution between 1998 and 2001. Exclusion criteria were as follows: age <16 years; pregnancy or lactation; presence of a dysplastic nevus syndrome, photosensitive dermatosis, autoimmune disease, or severe renal or hepatic

Results

Most patients achieved complete remission of psoriatic symptoms. Of 18 patients, 16 completed the study to the point where the PASI scores on both body halves were reduced by 75% or more. Of those 16 patients, 15 agreed to continue half-side treatments and ultimately achieved complete clearance of psoriatic lesions (PASI < 3, complete remission as defined in this study).

MPDs for contralateral body halves, which were determined after each of the first 4 weeks of PUVA therapy, were similar in

Discussion

In this study, bilateral comparisons of pairs of PUVA regimens revealed that reducing the frequency of PUVA treatments from 4 to 2 times/wk did not diminish the ability of PUVA to clear psoriatic skin lesions, provided similar weekly UVA doses were applied. For PUVA regimens of 2 treatments/wk, reducing the UVA dose from 1 MPD to 0.5 MPD per treatment did not affect overall therapeutic efficacy, although PUVA with the lesser MPD required a small increase (15%) in the number of PUVA treatments

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    Funding sources: None.

    Conflicts of interest: None identified.

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