Original Research

Comparison of Pneumatic Broadband Light Plus Adapalene Gel 0.3% Versus Adapalene Gel 0.3% Monotherapy in the Treatment of Mild to Moderate Acne

Author and Disclosure Information

Acne vulgaris is a common and distressing condition that typically presents in adolescents and young adults. The aim of this split-face, single-blind, randomized, controlled study was to determine if combination therapy with pneumatic broadband light (PBBL) plus adapalene gel 0.3% is superior to adapalene gel 0.3% monotherapy in the treatment of acne. Results indicated that the addition of PBBL to topical regimens may lead to quicker results and therefore may improve treatment adherence to topical therapies in acne patients.

Practice Points

  • Compliance is achieved when patients can see improvements with their acne treatments quickly.
  • Combination therapy achieves the goal of a quicker visual improvement of acneform pustules and papules with pneumatic broadband light while topical acne treatments have a chance to work, thus increasing compliance.



Acne is a common and distressing condition that typically presents in adolescents and young adults and has been associated with not only medical but also emotional and aesthetic consequences. Acne treatments that offer faster improvement are the coveted goal. Although clinical studies support the use of combination therapy with topical retinoids and antibiotics, the overuse of antibiotics raises caution for bacterial resistance.1 Therefore, adjunctive treatments such as chemical peels, light therapy, and laser treatments can hasten the response to traditional acne treatments and in some cases may potentially decrease use of both oral and topical antibiotics.

Light therapy, particularly with visible light, may improve acne outcomes. Pneumatic broadband light (PBBL) is a light treatment in the broadband range (400–1200 nm) combined with a vacuum. The suction created by the vacuum has several effects on acne lesions, such as creating a mechanical lysis of thin-walled pustules and dislodging pore impaction. The blue light with a wavelength of 410 nm targets endogenous porphyrins in Propionibacterium acnes and elicits singlet oxygen production, resulting in bacterial destruction.2,3 Studies showed that PBBL alone was effective in most patients with mild to moderate acne and caused minimal side effects.2-4

We sought to determine if PBBL combined with a topical retinoid can accelerate and prolong acne improvement. We evaluated the efficacy, safety, and tolerability of PBBL plus adapalene gel 0.3% versus adapalene gel 0.3% monotherapy in patients with mild to moderate acne.

METHODSPatient Population

Patients with mild to moderate acne were eligible for the study if they were 18 years or older at screening, in good health, had stopped oral isotretinoin for at least 1 year prior to treatment initiation, and were not taking oral or topical antibiotics or using any topical retinoid derivatives for at least 1 month prior to treatment initiation. Inclusion criteria included at least 10 acne lesions on the face. Patients were excluded if they had a history of receiving PBBL treatment; had a history of scarring, hypopigmentation, or hyperpigmentation from laser or light treatments; and/or were pregnant or refused use of contraception during the study period.

Study Design

This single-blind, randomized, split-face study was approved by the institutional review board of the University of Pennsylvania (Philadelphia, Pennsylvania). All participants provided informed consent before entering the study. Each participant was randomly assigned to receive PBBL on one side of the face for 6 consecutive weeks and apply adapalene gel 0.3% to both sides of the face nightly for 10 weeks. Pneumatic broadband light treatment was performed using the following settings: starting power 2 (approximately 4–6 J/cm2) and vacuum setting 3 (negative pressure, approximately 3 lb/in2). The power setting was increased to a maximum of 6 (12–14 J/cm2) at subsequent visits depending on tolerability of the participants.

All participants visited the clinic weekly for 6 weeks and also returned for follow-up at week 10 (4 weeks following last PBBL treatment). At each visit, the participants completed satisfaction questionnaires and were assessed by a dermatologist evaluator using several parameters including the modified Global Acne Grading Score (mGAGS), clinical photography, participant self-assessment, physician assessment, and Wong Baker FACES Pain Rating Scale (WBPRS). The physician evaluator was blinded to the side of the face receiving PBBL treatment. Clinical photographs were taken to compare the clinical outcome at each visit versus baseline.

Efficacy Evaluation

Acne Counts

The blinded evaluator counted acne lesions and assessed the mGAGS at each visit prior to administration of the PBBL treatment. Acne lesions were counted separately as noninflammatory (comedones) and inflammatory (papules, pustules, nodules) on the forehead, cheeks, nose, and chin.

Modified Global Acne Grading Score

The modified Global Acne Grading Score was modified from the Global Acne Grading Scale (GAGS) that has previously been used to evaluate acne severity.5 The original GAGS used the type and location of the acne lesions. The GAGS considers 6 locations on the face, chest, and upper back, with a grading factor for each location (forehead=2; cheeks=2; nose=1; chin=1). Another grading factor represented the lesion type (0=no lesion; 1=comedone; 2=papule; 3=pustule; 4=nodule). The local score was calculated by multiplying the location grading factor by the lesion type grading factor. The total score was the sum of the individual local scores for the 4 locations.

Given that the number of acne lesions is important, we modified the GAGS by adding a grading factor that represented the number of lesions to improve the accuracy of the test (1=0–10 lesions; 2=11–20 lesions; 3=21–30 lesions; 4=≥31 lesions). The local score of mGAGS was calculated by multiplying the grading factors for location, lesion type, and number of lesions. Each local score was then added to yield a total score. The mGAGS may be useful and more accurate to determine the severity of acne (0=none; 1–44=mild; 45–80=moderate; 81–132=severe; 133–176=very severe).


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