The first-line treatments for acne vulgaris are conventional topical and/or oral medications.
However, many patients have contraindications, only partial response, significant
adverse effects, or recurrence. Light-based treatments and photodynamic therapy (PDT)
using topical precursors of porphyrins are off-label alternative treatments for acne
vulgaris, with their own advantages and disadvantages. To date, there is no consensus
on PDT methodology and parameters. An understanding of pathophysiology of acne, light-tissue
interactions, and PDT mechanisms of action is helpful whenever PDT is considered as
an alternative treatment. In general, blue light alone improves acne because of its
antiinflammatory effects. PDT using 5-aminolevulenic acid (ALA) or ALA derivatives
induces transient antimicrobial and antiinflammatory effects. At high doses, red light
PDT may induce inhibition or destruction of sebaceous glands, resulting in clinical
improvement.
After completing this learning activity, participants should be able to compare different
treatments of acne, recognize when photodynamic therapy may be a useful off-label
treatment for acne vulgaris, and identify variables that may affect the efficacy of
photodynamic therapy.
Copyright 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All
rights reserved.