Drs. Thuangtong and Rattanaumpawan are from the Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand. Dr. Thuangtong is from the Department of Dermatology, and Dr. Rattanaumpawan is from the Department of Medicine. Dr. Tangjaturonrusamee is from the Institute of Dermatology, Department of Medical Services, Ministry of Public Health, Bangkok. Dr. Ditre is from the Department of Dermatology, Perelman School of Medicine at University of Pennsylvania, Philadelphia, and Penn Medicine Radnor, Pennsylvania.
The authors report no conflict of interest.
Correspondence: Chérie M. Ditre, MD, Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, 250 King of Prussia Rd, Radnor, PA 19087 (cherie.ditre@uphs.upenn.edu).
Twelve participants (2 males, 10 females) aged 17 to 36 years (median age, 22 years; mean age [SD], 23.33 [1.65] years) with both comedonal and inflammatory acne were enrolled into this study for 6 split-face treatments of salicylic acid 30% peel and PBBL at 1-week intervals for 6 weeks, with 2 subsequent follow-up sessions at weeks 3 and 6 posttreatment. Of the 12 participants, 11 were white and 1 was Asian American, with Fitzpatrick skin types II to IV. Nine participants (75%) completed the study. One participant dropped out of the study after the fourth treatment due to a scheduling conflict, and the other 2 participants did not return for follow-up. No participants withdrew from the study because of adverse therapeutic events.
Efficacy Evaluation
Comparisons between the salicylic acid 30% peel and PBBL procedures for mGAGS at each visit are shown in Table 2. There was no significant difference in treatment efficacy between the salicylic acid 30% peel and PBBL therapies during the study’s treatment and follow-up events; however, both procedures contributed to a major improvement in acne symptoms by the third treatment session and through to the last follow-up session (P≤.05). Clinical photographs at baseline, at last treatment visit (week 6), and at last follow-up (week 12) are shown in Figures 1 and 2.
Figure 1. A 19-year-old woman with mild acne who was treated with salicylic acid 30% peel on the right side of the face at baseline (A), week 6 (B), and week 12 (C).
Figure 2. A 19-year-old woman with mild acne who was treated with pneumatic broadband light on the left side of the face at baseline (A), week 6 (B), and week 12 (C).
The results of the acne QOL questionnaire are shown in Table2. Lower scores reflect a higher QOL. Median QOL scores at each visit ranged from 0.5 to 4.5. There was no significant difference found between the peel agent or PBBL based on the baseline QOL and subsequent visit assessments; however, the differences between the 2 treatments were significant at weeks 3 (P=.05) and 5 (P=.03) of treatment as well as at the last follow-up visit (P=.05).
According to the QOL scores, by the third treatment session participants were more satisfied with their improved acne condition from the PBBL procedure than the salicylic acid 30% peel as demonstrated by a positive range of the QOL assessments between PBBL and salicylic acid 30% peel (as shown in the difference in QOL in Table 2: week 3, 0–6; week 4, 0–3; week 5, 0–7). On the other hand, participants saw more improvement from the salicylic acid 30% peel than from PBBL by the last follow-up evaluation, as the differences in QOL scores between the 2 treatments resulted in a negative range (−5–0).
Safety
Pain assessment by the WBPRS at every visit showed a low pain rating associated with both salicylic acid 30% peel (range, 0–0.5) and PBBL (range, 1.0–1.5) treatments. The median pain score of the salicylic acid 30% peel appeared higher compared to the PBBL treatment, yet a significant difference between both treatments was seen only at weeks 1, 3, and 6 of treatment (P≤.05).
There were no unexpected therapeutic reactions reported in our study, and no participants withdrew from the study due to adverse events. Most participants experienced only mild adverse reactions, including redness, stinging, and a burning sensation on the salicylic acid 30% peel side, which were transient and disappeared in minutes; only redness occurred on the PBBL-treated side.
Comment
Facial acne treatment is challenging, as prolonged and/or severe acne contributes to scarring, declining self-confidence, and undesirable financial consequences. Even though salicylic acid peel is a commonly used acne treatment choice, the PBBL methodology was approved by the US Food and Drug Administration6 and has become an alternative procedure for acne treatment.
The pharmacological effects of salicylic acid are related to its corneocyte desquamation and exfoliative actions, thereby reducing corneocyte cohesion and unclogging follicular pores.16 Salicylic acid has been demonstrated to ameliorate inflammatory acne by its effects on the arachidonic acid cascade.2,4,17 In our study, salicylic acid 30% peel met participants’ satisfaction in acne improvement similar to a study showing a 50% improvement in acne scores after just 2 treatments.18 Our data support and corroborate that salicylic acid 30% peel renders an improvement in acne sequelae reported in several other studies.2,17,18
Pneumatic broadband light has been known to treat acne by the mechanism of pneumatic suction combined with photodynamic therapy using broadband-pulsed light (400–1200 nm).6-8 By applying the pneumatic device, a vacuum is created on the skin to remove sebum contents from follicles, whereas broadband light is emitted simultaneously to destroy bacteria and decrease the inflammatory process.7 During the vacuum process, the skin is stretched to reduce pain and avoid competitive chromophores (eg, hemoglobin), while the broadband light is administered.7 Broadband light encompasses 2 main light spectrums: blue light (415 nm) activates coproporphyrin III, which induces reactive free radicals and singlet oxygen species and has been reported to be the cause of bacterial cell death,19 and red light (633 nm), which renders an increase of fibroblast growth factors to work against the inflammatory processes.20 There are numerous studies showing a reduction of acne lesions after photopneumatic therapy with minimal side effects.6-8
In our study, we compared the efficacy of salicylic acid 30% peel with PBBL in the treatment of acne. Both treatments showed significant reduction of mGAGS compared to baseline starting from week 3 and lasting until week 12. Remarkably, although there were some participants who reported acne recurrence after completing all treatments at week 6, which could have happened when the treatments were ended, the final acne score at week 12 was still significantly lower than baseline. It is clear that the participants continued their acne improvement up to the 6-week follow-up period without any topical or oral medication. We do not propose that either salicylic acid peel or PBBL treatment is a solitary option but speculate that the combination of both treatments may initiate a faster resolution in the disappearance of acne.
Although there was no statistically significant difference in efficacy between salicylic acid 30% peel and PBBL procedures at each visit, QOL assessments related to treatment satisfaction did yield significant differences between baseline and the end of treatment. We noticed that participants had more positive attitudes toward the PBBL side at week 3 and week 5 but only mild satisfaction at week 4, as the differences in QOL scores between both treatments showed positive ranging values. This finding is most likely related to the immediate reduction of acne pustules by the PBBL vacuum lysis of these lesions. The differences in the QOL scores between both treatments at week 12 (the last follow-up evaluation) provided opposite findings, which meant patients had nearly even improvement in both PBBL method and salicylic acid 30% peel. Therefore, according to QOL data, acne disappeared quickly with the application of PBBL therapy but reappeared on the PBBL-treated side by the follow-up evaluations, though the acne score between both sides showed no statistically significant difference.
We reason that the PBBL therapy works better than salicylic acid 30% peel because the pneumatic system may help to unclog the pores through mechanical debridement via suctioning versus desquamation from salicylic acid 30% peel. Nonetheless, salicylic acid 30% peel sustained improvement when compared to PBBL through the follow-up periods. Both salicylic acid 30% peel and PBBL treatments are well tolerated and may initiate a faster resolution in the improvement of acne when incorporated with a medical program.
Because of the recurrence of acne after treatments were stopped, additional medical therapies are advised to be used along with this study’s clinical treatments to help mitigate the acne symptoms. These treatments should be considered in patients concerned about antibiotic resistance or those who cannot take oral antibiotics or retinoids. Salicylic acid peel is more accessible and affordable than PBBL, whereas PBBL is slightly more tolerable and less irritating than salicylic acid peel. Nevertheless, the cost of investment in PBBL is quite high—as much as $70,000—and does not include disposable, single-use tips, which cost $30 each. The machine is easy to set up, weighs about 40 lb, and requires little space to store. The average cost per visit of PBBL treatment in office is $150.00 and $75.00 for salicylic acid peel (unpublished data, Hospital of the University of Pennsylvania, 2010). Most patients may select salicylic acid peel over PBBL due to the cost and convenience of the treatment. Neither procedure should be considered as a solitary treatment option but rather as adjunctive procedures combined with oral and/or topical acne medications. After this study’s treatments were stopped and without other medications to maintain treatment effectiveness, the lesions reappeared, trending back toward baseline.
