通过临床研究，ALA—PDT治疗顽固性银屑病作为光疗的一种新方法已获得肯定疗效。研究分析了ALA—PDT疗效与银屑病皮损厚度、皮肤温度、药物封包时间、给药浓度、治疗次数、光源波长、照光剂量与不良反应等相关因素的影响，论述其临床疗效的差异性并对其进行评估，为进一步优化治疗方案提供理论依据。

Topical photodynamic therapy with 5-aminolevulinic acid(ALA-PDT) is a new method of light therapy for the treatment of recalcitrant psoriasis, and it has shown certain effectiveness. This article analyzes the relevant factors including the thickness of lesions, skin temperature, ALA concentration and incubation time, number of treatment, wavelength of light source, light dose and adverse reactions on the effectiveness of ALA-PDT for psoriasis. It also evaluates the clinical effectiveness and discusses its differences, which provides theoretical basis for further improving the treatment.