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Medical Lasers; Engineering, Basic Research, and Clinical Application 17
Original Article
Therapeutic Efficacy and Safety of Invasive Pulsed-Type Bipolar
Alternating Current Radiofrequency on Melasma and Rebound
Hyperpigmentation
Background and Objectives
Laser treatment for melasma is typically associated with various
complications, especially rebound hyperpigmentation (RH) and mottled
hypopigmentation. The purpose of this case review was to analyze the
clinical efficacy and safety of using an uinvasive pulsed-type bipolar
alternating current radiofrequency (IBPRF) for treating melasma with or
without RH.
Materials and Methods
Clinical improvement in the appearances of melasma and RH was analyzed
in 142 Korean patients (4 men and 138 women, with a mean age of 37.3 ± 11
years), who had undergone IBPRF treatment for melasma. IBPRF was
delivered at a frequency of 2 MHz and with non-insulated, penetrating
microneedles over five to 10 treatment sessions at 2- to 3-week intervals.
Results
In total, 124 patients had melasma, and among them,18 patients had
melasma with RH. To treat melasma, IBPRF alone was administered to
112 subjects, IBPRF plus a Q-switched Q-switched neodymium-yttrium-
aluminum-garnet (Nd:YAG) laser in 22 patients, IBPRF plus intralesional
tranexamic acid injection in five patients, and IBPRF plus bleaching
cream in three patients. Patients reported subjective satisfaction with the
appearance of their melasma lesions after seven to eight treatment
sessions, regardless of whether they underwent treatment with pulsed
RF alone or combination treatment. After treatment, no significant
complications, particularly RH or mottled hypopigmentation, were
recorded.
Conclusion
No severe complications related to IBPRF treatment were recorded, and
patients reported satisfaction in the appearance of their lesions after
seven to eight treatment sessions. This suggests that IBPRF may be
effective and safe for treating melasma and RH.
Key words
Invasive pulsed-type bipolar radiofrequency; Melasma; Postinflammatory
hyperpigmentation; Rebound hyperpigmentation
Hyoung Moon Kim
Min Ji Lee
Miaero Clinic, Seoul, Korea
Received June 19, 2017
Accepted June 21, 2017
Correspondence
Hyoung Moon Kim
Miaero Clinic, 164 Gwanak-ro, Gwanak-gu, Seoul
08788, Korea
Tel.: +82-2-871-7711
Fax: +82-2-876-7791
E-mail: drmac12@me.com
C
Korean Society for Laser Medicine and Surgery
CC
This is an open access article distributed under the
terms of the Creative Commons Attribution Non-
Commercial License (http://creativecommons.org/
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Med Laser 2017;6(1):17-23
https://doi.org/10.25289/ML.2017.6.1.17
pISSN 2287-8300ㆍeISSN 2288-0224
Original Article
Medical Lasers; Engineering, Basic Research, and Clinical Application
18
INTRODUCTION
Melasma is a commonly acquired hyperpigmentary
disorder characterized by light to dark brown macules
and patches occurring along the sun-exposed areas of
the face and neck.1 The treatment of melasma remains a
challenge. Numerous treatment options, including topical
agents, chemical peels, and laser treatments, have been
applied for treating melasma.1 Q-switched pigmentary
lasers have not been recommended for melasma treat-
ment due to a high incidence of postinflammatory hyper-
pigmentation (PIH) and unpredictable efficacy.1 Intense
pulsed light has shown some efficacy in the treatment
of melasma, although the risk of PIH still remains high.2
Fractional laser treatments have also been reported to
improve melasma. However, a recent report showed that
the therapeutic efficacy of fractional lasers did not differ
from that of conventional therapies.3
Recently, a 1064-nm Q-switched neodymium-yttrium-
aluminum-garnet (Nd:YAG) laser with low energy was in-
troduced for the treatment of melasma in Asian patients,
with favorable results.4-6 Patients experienced minimal
downtime without crust formation and significant erythe-
ma after laser treatment. Notwithstanding, the possibility
of rebound hyperpigmentation (RH) and punctate leuko-
derma have since been found to be the major concerns
for this treatment.7,8
Studies have shown that the skin behaves like a semi-
conductor.9 When emitted on the skin, radiofrequency
(RF) elicits epidermal and dermal heating. Electrical
conductivity is an important factor affecting RF conduc-
tion, and research has shown that tissue hydration and
temperature are important conductivity factors.10,11 When
RF current is applied to the skin, an electrobiological
change is elicited therein. At a minimal pulse duration,
however, little to no change in the epidermis and dermis
can be achieved: “pulsed” describes intermittent dura-
tions during which the laser is switched on and off. None-
theless, with time, various changes in the skin have been
recorded.10 The purpose of this study was to evaluate the
clinical efficacy and safety of treating melasma and RH
with invasive pulsed-type bipolar alternating current ra-
diofrequency (IBPRF) with non-insulated needles.
MATERIALS AND METHODS
Patients and radiofrequency treatment
The present study was conducted as a review of medi-
cal records for 142 patients who underwent treatment
with IBPRF for melasma with or without RH. The patients
were clinically diagnosed with melasma. After obtain-
ing written informed consent, melasma lesions with or
without RH were treated with pulsed-type RF in a bipolar
mode, at a frequency of 2 MHz, and with a disposable tip
comprising 25 non-insulated, penetrating microneedles
in a uniform 5 × 5 array (SYLFIRMTM; Viol, Kyunggi, Korea)
(Fig. 1). At baseline and one month after the final treat-
ment, photographs were taken under normal and ultra-
violet light exposures with an imaging tool to evaluate
improvement in the appearance of treated lesions.
All procedures using IBPRF were performed after ap-
plying local anesthesia with topical EMLA cream (eutectic
mixture of 2.5% lidocaine HCl and 2.5% prilocaine; Astra-
Zeneca AB, Södertälje, Sweden). Parameters for IBPRF
were set at level III and a 1.5-mm penetration depth over
a single session for treatment along the face and at level
II and a 1-mm depth for treatment along the forehead.
Overall, five to 10 treatment sessions were proceeded at
intervals of 2 to 3 weeks. Immediately after treatment, a
hydration mask pack was applied. Neither systemic nor
topical corticosteroids and antibiotics were prescribed
prophylactically to most of the patients. The patients were
recommended to apply a broad-spectrum sunscreen and
avoid excessive sun exposure during the course of laser
treatments.
Combined treatment
Among the 142 patients treated with IBPRF, a com-
bination of IBPRF plus a Q-switched Nd:YAG laser was
applied in 22, IBPRF plus intralesional tranexamic acid
injection was administered in five, and IBPRF plus bleach-
ing cream was applied in three. In each of the 22 patients
treated with a Q-switched Nd:YAG laser, the whole face
was treated with a 1,064-nm Q-switched single pulse
Nd:YAG laser with the settings of 1.0-1.2 J/cm2, a pulse
duration of 5-10-nsec, and a 7-mm spot size. A total of
Distance
:2mmNeedle
Length:3.5 mm
Thickness
: 0.3 mm
Fig. 1. Schematic illustration presenting the characteristics of
microneedle electrodes in a disposable tip.
Invasive Pulsed Bipolar Radiofrequency
Hyoung Moon Kim and Min Ji Lee
VOLUME 6 NUMBER 1 JUNE 2017 19
Original Article
2,000 to 2,500 shots were delivered on the entire face. The
IBPRF treatments were performed immediately there-
after. Intralesional tranexamic acid injection therapy was
delivered immediately after IBPRF treatment.
RESULTS
Over 1 year, a total of 142 patients underwent IBPRF
treatment for melasma with or without RH. Of these, 97%
were female and 3% were male. Fifteen patients reported
having had melasma for less than 1 year, 64 patients stat-
ed between 1 to 5 years, and 53 patients reported having
melasma for longer than 5 years but less than 10 years.
There were 10 patients who had melasma for more than
10 years. Regarding melasma types, 103 patients pre-
sented with melasma of centrofacial type, while the other
27 patients exhibited melasma of malar type.
Among all patients, 124 reported that they had not pre-
viously undergone treatment for melasma, while 18 had.
Of these 18 patients, laser toning was most commonly
used for melasma treatment, followed by treatment with
intense pulsed light or whitening ointment. Some had
also received combination treatment with a fractional
laser, tranexamic acid injection, and polydeoxyribonucleo-
tide injections. All 18 patients had undergone basic treat-
ment with laser toning combined with other treatment.
For melasma treatment, IBPRF alone was adminis-
tered in 112 subjects. A combination of IBPRF plus a Q-
switched Nd:YAG laser was applied in 22, IBPRF plus
intralesional tranexamic acid injection was administered
in five, and IBPRF plus bleaching cream was applied in
three. Surprisingly, patients generally reported subjective
A
B
Fig. 2. Representative photographs of a 46-year-old female patient with recurrent melasma. (A) Baseline and (B) one month after ten sessions of
invasive pulsed-type bipolar alternating current radiofrequency (IBPRF) monotherapy.
Medical Lasers; Engineering, Basic Research, and Clinical Application
20
satisfaction with the appearance of their melasma lesions
after seven to eight treatment sessions, regardless of
whether they underwent treatment with pulsed RF alone
or combination treatment (Figs. 2-4). Furthermore, most
of the patients exhibited overall clinical improvement in
skin texture and tone.
During the course of IBPRF treatment and follow up,
no significant complications, particularly RH or mottled
hypopigmentation, were recorded. The most common
complication was induration at the treatment area due to
excess exposure to radiofrequency energy; it disappeared
within 2 to 3 days of applying steroid ointment. Moreover,
no other side effects, including bruise, bleeding, oozing,
prolonged erythema, folliculitis, acneiform eruption, and
scarring, were encountered.
DISCUSSION
In the present study, we aimed to determine the clini-
cal efficacy and safety of treating melasma and PIH with
pulsed RF treatment. In 142 patients, IBPRF treatment
was delivered at a frequency of 2 MHz and with non-
insulated, penetrating microneedles over five to 10 treat-
ment sessions at 2- to 3-week intervals. After treatment,
no significant complications, particularly RH or mottled
hypopigmentation, were recorded.
Generally, melanin is not believed to be influenced by
RF treatment. We, however, suggest that morphological
or functional melanin structures are directly changed
upon RF irradiation of melasma lesions. The electrical
properties of melanin have been shown to be somewhat
unique, displaying both electrical conductivity and photo-
A
B
Fig. 3. Representative photographs of a 37-year-old female patient with melasma. (A) Baseline and (B) one month after six sessions of combined
IBPRF and laser toning treatment.
Invasive Pulsed Bipolar Radiofrequency
Hyoung Moon Kim and Min Ji Lee
VOLUME 6 NUMBER 1 JUNE 2017 21
Original Article
conductivity. Eumelanin, one of three basic forms of mel-
anin, shows pronounced electrical conductivity, both dark
and photo induced. Under certain humidity, temperature,
and electric field conditions, solid eumelanin pellets ex-
hibit threshold and memory switching.12 The electrical
properties (light, dark, DC, and AC) of eumelanin appear
to be dominated by the hydration state of the tissue, in
which a large range of DC electrical conductivities are re-
ported (10-15-10-13 S/cm).12 Based upon a typical Mott–Da-
vies model, activation energies have been calculated from
temperature dependent conductivity measurements,
from which a wide range of values are reported (c. 0.5 -
3.4 eV). Meanwhile, however, de Albuquerque et al. (2005,
2006) recently reported a value of 1.7 eV in synthetic eu-
melanin films using photo-pyro-electric spectroscopy.13
In addition to the above, RF treatment also appears
to stimulate healing of the basement membrane (BM).
Indeed, electrical current has been found to help induce
wound healing.14,15 Recently, pendulous melanocytes
have drawn greater interest in melasma treatment. High
energy laser treatment targets the BM, after which pen-
dulous melanocytes shift downward into the dermis.16 We
suggest that RF irradiation thickens and heals damaged
BMs for improvement in PIH.
Alternating current focuses along the outer surfaces of
conductors. This phenomenon is called the “skin effect”.17
This effect is beneficial to melasma treatment and pre-
venting PIH. For example, for fine vessels in the reticular
dermis, if the resistance of the reticular dermis is 400
mohm and the intravascular resistance is 0 mohm, alter-
nating current will accumulate on the vascular surface,
since vessels behave as conductors (Fig. 5). Thus, pulsed
A
B
Fig. 4. Representative photographs of a 56-year-old female patient with melasma and rebound hyperpigmentation. (A) Baseline and (B) one month
after eight sessions of IBPRF monotherapy.
Medical Lasers; Engineering, Basic Research, and Clinical Application
22
RF targets the vascular surface, and then, selective ves-
sels with a certain diameter are destroyed. Large ves-
sels remain intact due to the “sink effect,” which is more
important than the skin effect: the sink effect refers to
moving fluid (blood) that takes away heat energy from the
conductor surface. Thus, the selectivity of RF treatment
for vessel diameter can be applied to melasma or vas-
cular treatment to improve diffuse erythema after IBPRF
treatment.17
The dermal environment is also improved after RF
treatment. We suggest that, first, RF accelerates washing
out of dermal melanin, followed by stimulation of neocol-
lagenesis.18 This improved dermal environment helps
boost melasma and PIH treatment results. Nevertheless,
our propositions should be verified in biopsied results,
and the safety range of pulsed RF should be confirmed.
In conclusion, no severe complications related to IB-
PRF treatment were recorded in the present study, and
patients reported satisfaction in the appearance of their
lesions after seven to eight treatment sessions. Our expe-
riences suggest that IBPRF is effective and safe for treat-
ing melasma and RH.
ACKNOWLEDGEMENTS
We would like to thank Anthony Thomas Milliken, ELS
(Editing Synthase, Seoul, Korea) for his help with the edit-
ing of this manuscript.
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Fig. 5. Electrical current accumulates on the surface of the conductor
(vessel wall), known as the “skin effect.”
AC electrical current
Vessel wall
Electrode
0m
400 m
Electrical current
Dermis
Vessel lumen
(blood flow
= water)
Invasive Pulsed Bipolar Radiofrequency
Hyoung Moon Kim and Min Ji Lee
VOLUME 6 NUMBER 1 JUNE 2017 23
Original Article
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