Delta-aminolevulinic acid-based photodynamic therapy for acne on the body.

Intractable acne on the body was clinically treated with photodynamic therapy (PDT) combining oral administration of delta-aminolevulinic acid (ALA) with polychromatic visible light from a metal halide lamp. The total number of body acne patients was 51. A 10 mg/kg B.W. of ALA was administered to the patients, and the acne lesions were exposed to the light emitted from the metal halide lamp. The wavelengths of the light ranged from 540 to 800 nm. The diameter of the irradiated area and the irradiating distance from the lamp were 100 mm and 130 mm, respectively. Under the irradiation conditions, the total fluence rate and the energy-density uniformity of the light were 69.2 mW/cm2 and 11.5%. The total light energy dose in one session was 60-80 J/cm2 for the body. All patients underwent two sessions of PDT and received no other treatments after PDT or during the follow-up period. The interval between the two PDT sessions was 2-4 weeks. The physician's clinical assessment scores as worsened, unchanged, improved, and markedly improved were 0 (0%), 4 (7.8%), 16 (31.4%), and 31 (60.8%) patients, respectively. Adverse effects of very slight discomfort, burning, and stinging were reported during the irradiation. The blood tests of patients before and after oral administration of ALA demonstrated that no liver dysfunction occurred in this study with ALA dosages within 10 mg/kg B.W. Consequently, orally administered ALA-PDT with a metal halide lamp was considered to be effective for treatment of acne on the body.