Photodynamic therapy of acne vulgaris with topical delta-aminolaevulinic acid and incoherent light in Japanese patients.

BACKGROUND: Photodynamic therapy (PDT) is useful for treatment of epidermal neoplasia but may also have a role in the treatment of inflammatory dermatoses.
OBJECTIVES: To study the effect of PDT in patients with acne.
METHODS: Three men and 10 women who suffered from intractable acne vulgaris were treated using PDT with topical delta-aminolaevulinic acid (ALA) and polychromatic visible light. Twenty per cent ALA in an oil-in-water emulsion was applied to the lesions for 4 h with a light-shielding dressing. The lesions were then exposed to polychromatic visible light at 600-700 nm using a halogen light source of energy intensity 17 mW cm-2 and a total energy dose of 13 J cm-2.
RESULTS: All patients had apparent improvement of facial appearance and reduction of new acne lesions at 1, 3 and 6 months following PDT treatment. The adverse effects were discomfort, burning and stinging during irradiation, oedematous erythema for 3 days after PDT, epidermal exfoliation from the fourth to the 10th day, irritation and hypersensitivity to physical stimulation for 10 days after PDT, and pigmentation or erythema after epidermal exfoliation; the treated lesions returned to normal skin conditions within 1 month.
CONCLUSIONS: PDT was beneficial in the treatment of acne. As a photoactivating light source, polychromatic visible light was thought to be better for use with acne patients than laser light because of its cost-effectiveness, uniform illumination and time-efficiency in treating large areas.