`
`
`Skin Barrier Changes Induced by Aluminum Oxide and
`Sodium Chloride Microdermabrasion
`Poonam Rajan, MD* and Pearl E. Grimes, MD†‡
`*University of British Columbia, Vancouver, British Columbia, Canada, and †Vitiligo and Pigmentation Institute of
`Southern California and ‡Division of Dermatology, UCLA School of Medicine, Los Angeles, California
`
`background. Microdermabrasion has become an extremely
`popular method for superficial resurfacing. Despite the popu-
`larity of this technique, published studies of skin barrier func-
`tion changes following microdermabrasion are lacking.
`loss
`objective. To study assessed transepidermal water
`(TEWL), hydration, pH, and sebum production following alu-
`minum oxide (Al2O3) and sodium chloride (NaCl) microderm-
`abrasion.
`methods. Eight patients were included in this split face study.
`Transepidermal water loss, stratum corneum hydration, skin
`pH, and sebum production measurements were taken from the
`right and left sides of the face at baseline. One side of the face
`was treated with Al2O3 microdermabrasion and the other side
`
`with NaCl microdermabrasion. Measurements were repeated at
`24 hours and 7 days.
`results. Both NaCl and Al2O3 microdermabrasion was asso-
`ciated with a statistically significant increase in TEWL at 24
`hours. In contrast, at 7 days, levels of TEWL were decreased to
`less than baseline. In addition, an increase in hydration was ob-
`served 24 hours after NaCl and Al2O3 microdermabrasion. Hy-
`dration in NaCl-treated areas remained significantly increased
`at 7 days.
`conclusion. The results of this investigation suggest that both
`NaCl and Al2O3 microdermabrasion alter the epidermal barrier.
`These changes in epidermal barrier function may be responsible
`for the clinical improvement following microdermabrasion.
`
`P. RAJAN, MD AND P.E. GRIMES, MD HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS.
`
`MICRODERMABRASION HAS become an extremely
`popular form of superficial skin resurfacing. The tech-
`nique of microdermabrasion was first developed in Italy
`in 1985. Multiple units were subsequently marketed in
`Europe. Microdermabrasion units were introduced to
`North America by Mattioli Engineering in 1996–1997.
`Most units are closed-loop, negative-pressure systems
`which pass aluminum oxide (Al2O3) crystals onto the
`skin, while simultaneously vacuuming the used crys-
`tals. Other systems utilize sodium chloride (NaCl) and
`positive pressure for superficial skin resurfacing. Indi-
`cations for microdermabrasion include acne, acne scar-
`ring, hyperpigmentation, textural changes, and striae.
`Despite the popularity of microdermabrasion, we are
`aware of only a few studies published in peer-reviewed
`journals.1–3 Tsai et al.1 reported good to excellent re-
`sults in 41 patients treated with microdermabrasion for
`facial scarring. Shim et al.2 reported a statistically sig-
`nificant improvement in roughness, mottled pigmenta-
`tion, and overall improvement in skin appearance in
`14 patients. Currently we are not aware of any pub-
`lished study assessing changes in skin barrier function
`induced by microdermabrasion. Hence in this investi-
`gation, we proposed to evaluate transepidermal water
`
`Address correspondence and reprint requests to: Pearl E. Grimes, MD,
`321 North Larchmont Blvd., Suite 609, Los Angeles, CA 90004.
`
`loss (TEWL), hydration, pH, and sebum production
`following Al2O3 and NaCl microdermabrasion.
`
`Methods
`Patients
`Eight patients were included in this pilot study. There were
`four women and four men. Three were African American,
`three were Hispanic, and two were Caucasian. Their mean
`age was 32 years. Subjects were instructed to not wash their
`faces on the morning of study evaluation.
`Informed consent was obtained from each patient. Pa-
`tients were evaluated and treated at the Vitiligo and Pigmen-
`tation Institute of Southern California. Transepidermal water
`loss, stratum corneum hydration, skin pH, and sebum pro-
`duction were measured on the right and left side of the face
`at baseline and at 24 hours and 7 days after microdermabra-
`sion. Sebum measurements and skin pH were taken on the
`forehead. TEWL and hydration were measured on the cheeks.
`All measurements were performed in a controlled environ-
`ment with a room temperature of 20⬚C and humidity of 50–
`60%. All measurements were performed in triplicate.
`
`Measurements
`
`Transepidermal water loss was measured with a tewame-
`ter.4–7 The probe consisted of a hollow cylinder (10 mm in
`diameter, 20 mm in height) which was held in contact with
`
`© 2002 by the American Society for Dermatologic Surgery, Inc. • Published by Blackwell Publishing, Inc.
`ISSN: 1076-0512/02/$15.00/0 • Dermatol Surg 2002;28:390–393
`
`Sinclair Pharma et al.
`EUNSUNG-1025
`
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`Dermatol Surg 28:5:May 2002
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`rajan and grimes: al2o3 and nacl microdermabrasion
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`391
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`the facial skin surface until stable TEWL was established at
`3 minutes. The results were expressed as grams per square
`millimeter per hour.
`Stratum corneum hydration measurements were taken
`with a corneometer, which measured electrical capacitance
`of the skin as an indicator of stratum corneum hydration.4–7
`Capacitance was expressed digitally in arbitrary units. Wa-
`ter has the highest dielectric constant. Therefore as stratum
`corneum hydration increases, capacitance values also in-
`crease.
`Skin surface pH was measured with a pH meter using a
`glass electrode filled with a buffered measuring channel.4–8
`The inner buffer is separated from the measuring channel by
`a glass membrane.
`Forehead sebum measurements were taken with a sebu-
`meter.4–7 The sebumeter utilizes a cassette tape applied to
`the forehead for 30 seconds. Sebum measurements were ex-
`pressed as micrograms of sebum per square centimeter.
`
`Microdermabrasion Procedure
`
`Prior to performing microdermabrasion, the patients’ faces
`were cleansed with skin cleanser and water. One side of the
`face was microdermabraded with an Al2O3 unit. The con-
`tralateral side was treated with an NaCl unit. Three passes
`were performed with each machine. Skin cleanser and mois-
`turizer were applied on the treated areas by the patients af-
`ter microdermabrasion. Barrier function measurements and
`microdermabrasion were performed by blinded and sepa-
`rate investigators.
`
`Statistical Analysis
`
`Mean values were calculated based on measurements of
`TEWL, hydration (expressed as capacitance), skin surface
`pH, and sebum. Paired t-test was employed to compare
`mean values.
`
`Results
`Compared to baseline, a statistically significant in-
`crease in TEWL was observed at 24 hours following
`both NaCl (P ⫽ .01) and Al2O3 microdermabrasion
`(P ⫽ .02; Figure 1). Seven days after microdermabra-
`sion there was a decrease in the mean values for
`TEWL to levels below baseline for both NaCl and
`Al2O3 (P ⬍ .05). There were no statistically significant
`differences between the values attained for NaCl and
`Al2O3 groups at baseline 24 hours or 7 days following
`microdermabrasion.
`Compared to baseline, both the NaCl and Al2O3
`groups demonstrated an increase in the mean values
`for hydration (expressed as capacitance) at 24 hours
`following microdermabrasion (P ⬍ .05; Figure 2).
`Compared to baseline, NaCl demonstrated a statisti-
`cally significant increase in stratum corneum hydra-
`tion at 7 days (P ⬍ .05). Al2O3 showed a similar trend
`
`Figure 1. Comparison of baseline with 24-hour and 7-day mean
`values (⫾ standard error) for TEWL following NaCl and Al2O3 mi-
`crodermabrasion. Differences were statistically significant at 24
`hours compared to baseline; NaCl (P ⫽ .01), Al2O3 (P ⫽ .02).
`
`at 7 days compared to baseline (P ⫽ .07). There was
`no statistically significant difference between the NaCl
`group and the Al2O3-treated groups at baseline, 24
`hours, and 7 days.
`The mean pH measurements for both NaCl and
`Al2O3 groups decreased (ie, more acidic) at 24 hours
`after microdermabrasion compared to baseline (Figure
`3). At 7 days after microdermabrasion there was a
`slight increase in pH values for both the NaCl and
`Al2O3 groups compared to the values at 24 hours.
`However, the differences among the baseline, 24-
`hour, and 7-day levels were not statistically signifi-
`cant. There also was no statistically significant differ-
`ence between the NaCl and Al2O3 groups at baseline,
`24 hours, and 7 days.
`Mean values for sebum secretion for both NaCl
`and Al2O3 groups were decreased at 24 hours com-
`
`Figure 2. Comparison of baseline with 24-hour and 7-day mean
`values (⫾ standard error) for capacitance (reflecting hydration)
`following NaCl and Al2O3 microdermabrasion. Capacitance is mea-
`sured in digital units. NaCl microdermabrasion was associated with
`a statistically significant increase in hydration at 7 days (P ⬍ .05).
`
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`rajan and grimes: al2o3 and nacl microdermabrasion
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`Dermatol Surg 28:5:May 2002
`
`Figure 3. Mean pH values (⫾ standard error) at baseline and at 24
`hours and 7 days following NaCl and Al2O3 microdermabrasion
`(p ⬎ .05).
`
`Figure 4. Mean sebum secretion in micrograms per square centi-
`meter (⫾ standard error) at baseline and at 24 hours and 7 days
`following NaCl and Al2O3 microdermabrasion (p ⬎ .05).
`
`pared to baseline (Figure 4). At 7 days, NaCl demon-
`strated increased levels of sebum secretion compared
`to baseline. Sebum secretion at 7 days after Al2O3 mi-
`crodermabrasion was slightly less than the values at
`24 hours. However, the differences among the base-
`line, 24-hour, and 7-day levels were not statistically
`significant. There also was no statistically significant
`difference between the NaCl and Al2O3 groups at
`baseline, 24 hours, and 7 days.
`
`Conclusion
`Microdermabrasion is one of the most recent addi-
`tions to the dermatologist’s armamentarium of resur-
`facing techniques. There are currently several units
`available on the market, most of which are closed-
`loop systems that pass Al2O3 crystals onto the skin
`while simultaneously vacuuming the used crystals.
`Other systems utilize NaCl and positive pressure for
`superficial resurfacing. To date, there are only a few
`published studies regarding the science of microderm-
`abrasion. Several clinical studies have reported the ef-
`ficacy of microdermabrasion for treatment of hyper-
`pigmentation, acne scarring, postsurgical scarring, striae,
`and fine wrinkles.1–3 We are not aware of published stud-
`ies on the physiologic changes induced by microderm-
`abrasion in the stratum corneum and epidermis. The
`present investigation assessed alterations in the skin
`barrier following microdermabrasion. In order to mea-
`sure physiologic changes, we employed methodology
`currently accepted as the gold standard for measuring
`epidermal barrier parameters.4–7
`At baseline there were no statistically significant
`differences between either side of the patients’ face.
`This demonstrates matched baseline controls for the
`NaCl and Al2O3 microdermabrasion groups. In the
`acute phase (ie, 24 hours after microdermabrasion) we
`
`observed a statistically significant increase in TEWL.
`This provides evidence for disruption of the lipid bar-
`rier of the epidermis by microdermabrasion. At 7 days
`there was a drop in TEWL to mean values slightly less
`than those seen at baseline. This suggests that restora-
`tion of barrier function has occurred, with a trend to-
`ward improvement in the lipid barrier function over
`baseline. A statistically significant increase in stratum
`corneum hydration was observed at 7 days with NaCl
`microdermabrasion, and a similar trend was seen with
`Al2O3. Taken together, our results suggest enhanced
`lipid barrier function through decreased TEWL and
`increased hydration in the regenerated stratum cor-
`neum 7 days after both NaCl and Al2O3 microderm-
`abrasion. These findings likely underlie the improved
`clinical appearance of supple and more hydrated-look-
`ing skin after microdermabrasion.
`Berardesca et al.8 demonstrated that partial re-
`moval of layers of the stratum corneum results in acid-
`ification of the stratum corneum, whereas complete
`removal of the stratum corneum leads to alkaliniza-
`tion. Mauru et al.9 showed that certain enzymes re-
`quired for lipid formation in the stratum corneum
`require an acidic environment, with an optimal pH of
`5.5. Our results demonstrate a trend toward a de-
`crease in pH at 24 hours after microdermabrasion,
`signifying partial removal of the stratum corneum.
`This decrease in pH likely contributes to an environ-
`ment conducive to regeneration of the lipid barrier in
`the stratum corneum. At 7 days after NaCl micro-
`dermabrasion, we demonstrated a trend toward in-
`creased sebum secretion levels. This finding also may
`reflect restoration of the skin lipid barrier.
`Following microdermabrasion, the physiologic changes
`in the epidermal barrier may be responsible for the ob-
`servations of clinical improvement.1–3 Multiple studies
`have documented the role of adequate stratum cor-
`neum hydration and moisturization in maintaining the
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`feel and appearance of healthy skin.10,11 Our findings
`provide the first evidence that a regenerated and/or al-
`tered stratum corneum following microdermabrasion
`likely stimulates enhanced skin hydration and less
`TEWL. These barrier alterations may result in the im-
`proved texture and overall appearance of microderm-
`abraded skin. Longer-term prospective studies with an
`increased number of patients are indicated to provide
`further support for and elucidate the illustrated bene-
`ficial effects of microdermabrasion on skin.
`
`Acknowledgment P. Rajan received a mentorship grant
`from the Women’s Dermatologic Society.
`
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