Photodynamic Therapy
Aminolevulinic acid and photodynamic therapy (ALA-PDT) has been successfully used in the management of acne.10 In addition to inducing selective damage to sebaceous glands, it has been proposed that PDT also destroys Propionibacterium acnes and reduces keratinocyte shedding and immunologic changes that play key roles in the development of acne.10
A recent randomized controlled trial comparing the efficacy of ALA-PDT vs adapalene gel plus oral doxycycline for treatment of moderate acne included 46 patients with moderate inflammatory acne.10 Twenty-three participants received 2 sessions (spaced 2 weeks apart) of 20% ALA incubated for 90 minutes before red light irradiation with a fluence of 37 J/cm2, and the other 23 received 100 mg/d of oral doxycycline plus adapalene gel 0.1%. By 6-week follow-up, there was a significantly higher reduction in total lesions within the PDT group (P=.038), which was sustained at the secondary 12-week follow-up (P=.026). There was a 79% total reduction of lesions in the ALA-PDT group vs 67% in the doxycycline plus adapalene group.10
Although some studies have shown promise for PDT as an emerging treatment option for acne, further research is needed. A 2016 systematic review of the related literature determined that although 20% ALA-PDT with red light was more effective than lower concentrations of ALA and also more effective than ALA-PDT with blue light—which offered no additional benefit when compared with blue light alone—high-quality evidence on the use of PDT for acne is lacking overall.11 At the time of the review, there was little certainty as to the usefulness of ALA-PDT with red or blue light as a standard treatment for individuals with moderate to severe acne. A 2019 review by Marson and Baldwin12 echoed this sentiment, recommending more stringently designed studies to elucidate the true role of PDT as a monotherapy or adjunctive treatment of acne.
Pulsed Dye Laser
Pulsed dye laser (PDL) was first shown to be a potential therapy for acne by Seaton et al,13 who conducted a small-scale, randomized, controlled trial with 41 patients, each assigned to either a single PDL treatment or a sham treatment. Patients were re-evaluated at 12 weeks, measuring acne severity by the Leeds revised acne grading system and taking total lesion counts. Acne severity (P=.007) and total lesion counts (P=.023) were significantly improved in the treatment group, with a 53% reduction in total lesion count following a single PDL treatment.13
In 2007, a Spanish study described use of PDL every 4 weeks for a total of 12 weeks in 36 patients with mild to moderate acne. Using lesion counts as their primary outcome measure, the investigators found results similar to those from Seaton et al,13 with a 57% decrease in active lesions.14 Others still have found similar outcomes. A 2009 study of 45 patients with mild to moderate acne compared patients treated with PDL every 2 weeks for 12 weeks to patients receiving either topical therapy or chemical peels with 25% trichloroacetic acid. At 12 weeks, they noted the best results were in the PDL group.15
Karsai et al16 compared PDL as an adjuvant treatment of acne to proven treatment with clindamycin plus benzoyl peroxide gel. Eighty patients were randomized to topical therapy plus PDL or topical therapy alone and were followed at 2 and 4 weeks after the initial treatment. Although both groups showed improvement as measured by inflammatory lesion count and dermatology life quality index, there was no statistically significant difference noted between groups.16