COMMENT
This 10-week study demonstrated that PBBL initially improved the appearance of acne in the first month of treatment, as determined by the significantly greater reduction in mGAGS for the combination side versus the adapalene monotherapy side. Differences in the reduction of acne lesions were not significant between the 2 treatments, except for noninflammatory lesion reduction at week 3. Analysis of physician assessment with photographs revealed acne improvement from baseline in the first month but no additional effects with the PBBL treatment at the end of study. Similarly, participant assessment indicated an improvement by week 2 with the combination therapy compared to adapalene monotherapy in their assessment of acne lesion reductions from baseline. By the end of the study, there was no significant difference between monotherapy and combination therapy.
These findings illustrate that combination therapy with PBBL plus adapalene improved the appearance of acne lesions within the first month of treatment, but there were no further signs of improvement at weeks 5 and 6. These results are consistent with at least 2 other studies that demonstrated acne reduction within the first 3 weeks of PBBL treatment.2,4 The current study was completed as planned with 6 weeks of combination therapy and patients continued adapalene application until the last follow-up visit in week 10. The length of the combination treatment was enough to determine that extension of treatment would not be necessary to gain any further benefits in this study. Because of the small sample size, we would not be able to detect any significant differences, as the difference between the combination therapy and the adapalene monotherapy was less than 55%. Therefore, a future study with a larger sample size is needed to draw a better conclusion.
Pneumatic broadband light has shown impressive results in acne treatment. However, some side effects need to be considered. Minimal adverse events have been reported such as erythema, dryness, peeling, burning, and itching.2-4 In this study, we found that all patients experienced transient erythema during and after PBBL treatment, but this effect disappeared in minutes. Purpura can occur if a higher power of PBBL is performed (6 or greater). Black patients experienced hyperpigmentation that can occur in darker skin types, as reported when light therapy is performed despite using the correct skin type tips.8 Therefore, care must be used in darker skin types, and we advocate a skin test in this population prior to general use.
Our study showed that PBBL can be safely combined with adapalene gel 0.3% and is well tolerated in the treatment of mild to moderate facial acne vulgaris for patients with Fitzpatrick skin types I to III. The combination of PBBL and adapalene reduces acne severity, as shown by the reduction in mGAGS during the first month of treatment. Patients noted faster improvement in their acne lesions with this combination. Although this study was limited by a relatively small sample size, this information may be useful in getting patients to be compliant overall, as they appeared to see results sooner, giving other therapies time to initiate their effect. It appears that 4 consecutive weekly treatments are enough to see that effect. Additionally, this combination therapy provides results without having to resort to oral antibiotics, as many patients today are concerned about creating future antibiotic resistance.
Conclusion
Adapalene gel 0.3% can be safely combined with PBBL for treatment of mild to moderate acne. Although the benefits of this combination therapy can be seen after 4 consecutive weekly treatments, the beneficial effect is not sustained.
Acknowledgment
The authors would like to thank Joyce Okawa, RN (Philadelphia, Pennsylvania), for her assistance in the submission to the University of Pennsylvania institutional review board.