REVIEWS  ADVANCES IN PSORIASIS 

Giornale Italiano di Dermatologia e Venereologia 2007 October;142(5):593-601

Copyright © 2007 EDIZIONI MINERVA MEDICA

language: English

Psoriasis and photodynamic therapy

Kostovic K., Zoric Z., Pasic A., Ceovic R.

Department of Dermatology and Venereology Zagreb University Hospital Center Zagreb, Croatia

Photodynamic therapy (PDT) is a two-step therapeutic technique involving the administration of photosensitizer followed by visible light irradiation. 5-Aminolevulinic acid (ALA) is not a photosensitizer by itself but is metabolized to photosensitive protoporphyrin IX through the intrinsic cellular heme biosynthetic pathway. Light sources available for PDT belong to three broad groups: broadband lamps, diode lamps and lasers. Evidence from many clinical trials support the use of PDT in nonhyperkeratotic actinic keratoses on the face and scalp, Bowen’s disease, and superficial basal cell carcinomas. This review appraises present experience with the use of topical ALA-PDT in the treatment of psoriasis. There is a fair amount of literature devoted to the treatment of psoriasis with PDT; however, the outcomes vary, imposing the question whether PDT is a useful therapeutic alternative. Pain, the variability of therapeutic effect, mediocre results and associated discomfort make ALA-PDT unsuitable for the treatment of extensive psoriasis. Yet, in some patients with limited chronic plaque psoriasis where conventional treatments have failed, PDT can be an alternative option. There is strong evidence on a preferential uptake of photosensitizers in psoriatic plaques and confirmation by biological markers that specific antipsoriatic changes take place during PDT. Additional studies are needed to clarify the optimal use of photosensitizers and treatment parameters that may minimize these problems.