Reduction of treatment frequency and UVA dose does not substantially compromise the antipsoriatic effect of oral psoralen-UVA.
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.
Legat
Franz J
FJ
Division of Photodermatology, Department of Dermatology, Medical University Graz Austria.
Hofer
Angelika
A
Quehenberger
Franz
F
Kahofer
Peter
P
Kerl
Helmut
H
Wolf
Peter
P
D000284:Administration, Oral; D000328:Adult; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D008730:Methoxsalen / Q000008:administration & dosage; D011701:PUVA Therapy / Q000379:methods*; D011446:Prospective Studies; D011565:Psoriasis / Q000188:drug therapy*; D016896:Treatment Outcome
D008730:Methoxsalen