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/cm2. 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 < .0001) but only by 0.999 times for a one-unit increase in ALA dose (95% CI 0.998-1.000  =  .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.