Prospective Study of Topical 5-Aminolevulinic Acid Photodynamic Therapy for the Treatment of Moderate to Severe Acne Vulgaris in Chinese Patients

Background: Topical photodynamic therapy (PDT) mediated with 5-aminolevulinic acid (ALA) offers an alternative option for the treatment of acne vulgaris. Objective: To study the effects of ALA dose, incubation time, and lesion type on protoporphyrin IX (PpIX) production and treatment outcomes. Methods: To examine the time course of PpIX production, 10% ALA was applied to inflammatory papules for 1 to 5 hours and followed by in situ fluorescence examination. To determine the effects of ALA dose and lesion type, 3, 5, and 10% ALA was applied to acne lesions in split-face fashion for 3 hours followed by whole-face light irradiation at 633 nm and 30 to 70 J/cm(2). Treatment was repeated twice at 2-week intervals. Results: PpIX reached a stable level after 3 hours of incubation. Similar PpIX levels were seen in areas receiving 3, 5, and 10% ALA. Poisson regression analyses indicated that lesion counts decreased by 0.791 times for a one-unit increase in treatment times (95% CI 0.782-0.799, p < .0001) but only by 0.999 times for a one-unit increase in ALA dose (95% CI 0.998-1.000, p = .22). Conclusion: The combination of low-dose ALA and a red light is a safe and effective option for the treatment of moderate to severe acne.