[Therapeutic effect of photodynamic treatment for psoriasis vulgaris in guinea pigs].

OBJECTIVE

To observe the efficacy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) for treating psoriasis vulgaris in guinea pigs.

METHODS

Experimental psoriasis vulgaris was induced in guinea pigs by application of 5% propranolol on the ear skin. After dressing of the skin lesion with 20% ALA solution for 4 h, the lesions were irradiated with a semiconductor laser at the wavelength of 635 nm and energy density of 12 J/cm(2). The guinea pigs were divided into control group, ALA only group, light only group, single ALA-PDT treatment group and twice ALA-PDT treatment group. In each group, gross observation and biopsy of the skin lesions was conducted on days 7, 14, 21 and 28 after the treatment.

RESULTS

In terms of gross observation of the lesion, epidermal thickness and proliferating cell nuclear antigen (PCNA) expression, ALA-PDT treatment showed obvious therapeutic effect on the skin lesion, and two treatment sessions resulted in better effect than a single session.

CONCLUSION

ALA-PDT can cure psoriasis vulgaris lesions characterized by abnormal epidermal proliferation in guinea pigs, and multiple treatment sessions can achieve better effects.