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Abstract and IntroductionAbstractThe Asian patient with
Fitzpatrick skin types III-V is rarely highlighted in publications
on cutaneous disorders or cutaneouslaser surgery. However, with
changing demographics, Asians will become an increasingly important
group in this context.Although high melanin content confers better
photoprotection, photodamage in the form of pigmentary disorders is
common.Melasma, freckles, and lentigines are the epidermal
disorders commonly seen, whilst nevus of Ota and acquired
bilateralnevus of Ota-like macules are common dermal pigmentary
disorders. Post-inflammatory hyperpigmentation (PIH) occurringafter
cutaneous injury remains a hallmark of skin of color. With
increasing use of lasers and light sources in Asians,prevention and
management of PIH is of great research interest. Bleaching agents,
chemical peels, intense pulsed light(IPL) treatments, and
fractional skin resurfacing have all been used with some success
for the management of melasma.Q-switched (QS) lasers are effective
for the management of epidermal pigmentation but are associated
with a high risk ofPIH. Long-pulsed neodymium-doped yttrium
aluminum garnet (Nd:YAG) lasers and IPL sources pose less of a PIH
risk butrequire a greater number of treatment sessions. Dermal
pigmentary disorders are better targeted by QS ruby, QSalexandrite,
and QS 1064-nm Nd:YAG lasers, but hyper- and hypopigmentation may
occur. Non-ablative skin rejuvenationusing a combination approach
with different lasers and light sources in conjunction with cooling
devices allows different skinchromophores to be targeted and
optimal results to be achieved, even in skin of color. Deep-tissue
heating usingradiofrequency and infra-red light sources affects the
deep dermis and achieves enhanced skin tightening, resulting
ineyebrow elevation, rhytide reduction, and contouring of the lower
face and jawline. For management of severe degrees ofphotoaging,
fractional resurfacing is useful for wrinkle and pigment reduction,
as well as acne scarring.
Acne, which is common in Asians, can be treated with topical and
oral antibacterials, hormonal treatments, and
isotretinoin.Infra-red diode lasers used with a low-fluence,
multiple-pass approach have also been shown to be effective with
fewcomplications. Fractional skin resurfacing is very useful for
improving the appearance of acne scarring. Hypertrophic andkeloid
scarring, another common condition seen in Asians, can be treated
with the combined used of intralesionaltriamcinolone and
fluorouracil, followed by pulsed-dye laser. Esthetic enhancement
procedures such as botulinum toxin typeA and fillers are becoming
increasingly popular. These are effective for rhytide improvement
and facial or body contouring.We highlight the differences between
Asian skin and other skin types and review conditions common in
skin of color togetherwith treatment strategies.
IntroductionPopulation demographics have evolved in the 21st
century such that over half the world's population is Asian.[1] The
USCensus 2000 reported that 4.2% of the US population was of Asian
origin.[2] Furthermore, this fastest growing group in theUS
population is projected to double in size by 2050.[3] The term
Asian refers to people having origins from the Far East,southeast
Asia, or the Indian subcontinent.[2] They are a diverse group with
various skin phototypes ranging from Fitzpatricktype III to V in
the Chinese and Japanese to type IV and V in Indians and
Pakistanis. We review cutaneous disorders thatare common or
particular to skin of color (with particular emphasis on Asian
patients) and discuss the management of theseconditions.
1. Photoaging in AsiansNinety-five percent of the visible signs
of aging are caused by sun exposure, which begins in infancy and
continuesthroughout life. Other intrinsic factors such as gravity
and pollution also contribute to the cutaneous aging
process.[4]
Skin of color is differentiated by the amount and epidermal
distribution of melanin. Szabo[5] established that although
there
The Asian Dermatologic Patient: Review ofCommon Pigmentary
Disorders andCutaneous DiseasesStephanie G.Y. Ho, Henry H.L. ChanAm
J Clin Dermatol. 2009;10(3):153-168.
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are no racial differences in melanocyte density, darker skin has
larger melanocytes producing more melanin and themelanosomes are
distributed individually in keratinocytes. The increased melanin
and more dispersed melanosomes appearto absorb and deflect UV light
more efficiently, conferring significant photoprotection to skin of
color.[6] Tadokoro et al.[7]confirmed this by showing a close
inverse correlation between melanin content in the skin and the
amount of DNA damageresulting from a given dose of UV
radiation.
Despite this, Kotrajaras and Kligman[8] reported that
significant photodamage in the form of epidermal atypia and
atrophy,dermal collagen and elastin damage, and pigmentary
disorders can occur in skin of color. Other investigators have
similarlyobserved that pigmentary changes occur with a greater
incidence than skin wrinkling in Asians.[9,10] Chung[11] more
recentlyfound both pigmentary changes and wrinkling to be major
features of photoaging in Asians. However,
moderate-to-severewrinkling becomes apparent only at about 50 years
of age, which is a decade or two later than in
age-matchedCaucasians.[4]
Other cutaneous manifestations of aging ethnic skin include the
development of benign cutaneous growths such asdermatosis papulosa
nigra, seborrheic keratoses, and the development of solar
lentigines.[4,11]
2. Disorders of Pigmentation2.1 Post-Inflammatory
HyperpigmentationPost-inflammatory hyperpigmentation (PIH) is a
common pigmentary disorder in melanin-rich Asian skin.[12] PIH can
beconsidered the default pathophysiologic response to cutaneous
injury in such individuals. Several factors contribute to
thedevelopment of PIH, including increased melanocytic activities,
dermal melanophages, and hemosiderin depositionsecondary to
hemorrhage. The severity of PIH is related to the degree of
inflammation and extent of disruption of theepidermo-dermal
junction. It may be caused by endogenous inflammatory skin
disorders or iatrogenic sources such aslasers.[13] The high
epidermal melanin content in Asian skin may act as a competing
chromophobe for vascular and pigmentlasers, interfering with the
absorption of laser energy that is intended for another target.
With increasing use of lasers andlight sources in Asians,
prevention and management of PIH is becoming increasingly
important.[14] This will be discussed inmore detail in subsequent
sections.
2.2 MelasmaMelasma is an acquired symmetric hypermelanosis
involving sun-exposed areas commonly seen in Asian
middle-agedwomen. Genetics, UV radiation, pregnancy, hormonal
therapies, and other phototoxic drugs are all thought to be
contributingetiologic factors and melasma remains a difficult
condition to treat. Melasma was formerly classified
histopathologically asepidermal, dermal, or mixed type depending on
the location of the pigment.[15] However, Kang et al.,[16] in a
histopathologicstudy of 56 Korean patients with melasma, suggested
that there is no true dermal type and the dermal melanophages
seenin 'dermal-type melasma' may be due to undiagnosed acquired
bilateral nevus of Ota-like macules or Hori's macules.
In a study comparing the histopathologic features of melasma
with those of normal skin using several
differentimmunohistochemical stains, Kang et al.[16] reported that
melasma skin had more melanin in the whole epidermis whereasmelanin
is confined to the basal layer in normal skin. Increased numbers of
melanocytes and widely dispersed melanosomesin keratinocytes are
also found in melasma lesions. These investigators proposed that
increased activity of melanogenicenzymes results in hyperactive
melanocytes with increased synthesis and transfer of melanosomes,
and decreaseddegradation in keratinocytes. Sublethal laser damage
to these labile melanocytes can increase the production of
melaninand lead to PIH.[16] This may explain why previous studies
using a 510-nm pigmented lesion dye laser[17] and a Q-switched(QS)
ruby laser[18] for the management of melasma led to little
improvement and worsening of pigmentation in some cases.Recent
studies have also indicated that intense pulsed light (IPL) can
lead to manifestation of previously subclinicalmelasma; for this
reason, Wood's light examination or UV photography prior to IPL
treatment of Asian skin is recommended.[19,20]Use of bleaching
agents and sunscreens for at least 6 weeks, and preferably for 3
months, prior to any laser or light therapycan help suppress the
function of these hyperactive melanocytes and reduce the risk of
PIH.[14] Even with such precautions,a recent study in Taipei[20]
that compared topical bleaching treatment only with bleaching plus
IPL treatment for melasmareported two cases of PIH in the
IPL-treated group despite prolonged use of bleaching agents and
sunscreens prior totreatment.
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Combinations of hydroquinone with topical corticosteroids and
tretinoin have been reported to be effective as first-linetreatment
of melasma.[21,22] The limitations of topical treatment include the
longer time required for effectiveness to becomeapparent and
patient compliance. Glycolic acid, salicylic acid, and
trichloroacetic acid peels are also useful adjuncts totopical
treatments in the management of melasma in Asians.[23-25]
Wang et al.[20] in Taipei showed that patients with melasma in
the IPL-treated group achieved a significant improvement of39.8%
compared with 11.6% in the control group after four sessions of IPL
and topical treatment. However, partialrepigmentation was noted 24
weeks later, suggesting the need for repeated treatments for
maintenance. These investigatorssuggested use of the lowest fluence
to achieve minimal erythema, a recommendation supported by the
findings of Negishi etal.[19] This avoids excessive thermal injury
to labile melanocytes and reduces the risk of PIH.
Ablative lasers such as carbon dioxide lasers and QS alexandrite
lasers have been used with some success in the treatmentof
melasma.[26-28] These lasers are thought to prevent the clonal
expansion of hyperactive melanocytes located in theepidermal basal
layer. In addition, ablative lasers may increase the topical
absorption of bleaching agents in patients withimpaired epidermal
barrier function. However, the significant downtime and adverse
effects associated with the use ofablative lasers has made them
unpopular.
Fractional skin resurfacing is a recent development in the
management of melasma (figure 1). This involves the use of a1540-nm
laser that creates microscopic zones of thermal injury that are
surrounded by normal skin. As the areas of thermalinjury are very
small, lateral migration of keratinocytes to them occurs rapidly,
leading to re-epithelialization of the epidermiswithin 24
hours.[14] Rokhsar and Fitzpatrick[29] conducted a small study that
evaluated use of fractional resurfacing (Fraxel,Reliant
Technologies, Mountain View, CA, USA) in the treatment of melasma.
In their ten subjects, using 6-12 mJ at2000-3500 microthermal
treatment zone (MTZ)/cm2 as treatment parameters, 60% reported
75-100% clearing of melasma,30% reported
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Figure 1.
Treatment of melasma with fractional skin resurfacing: (a)
pre-treatment; (b) post-treatment.
2.3 Freckles and LentiginesFreckles and lentigines are common
benign pigmented lesions seen in Asians. As the cultural trend in
Asians movestowards fair porcelain skin, these pigmented lesions
can often present in dermatology outpatients as a cosmetic
concern.
Freckles or ephelides occur in adolescence and are relatively
uniform in distribution, size, and color.
Histopathologically,epidermal hypermelanosis without an increase in
melanocyte number is seen. Lentigines increase in number and
prevalencewith age. They tend to vary in size and color and are
non-uniformly distributed. Histologically, the number of
melanocytesand epidermal hypermelanosis are increased and the
epidermal rete ridges are elongated.[30]
Anderson et al.[31] were the first to demonstrate the
effectiveness of QS neodymium-doped yttrium aluminum garnet(Nd:YAG)
laser in the treatment of cutaneous pigmentation. However, studies
using QS Nd:YAG, QS ruby, and QSalexandrite lasers for pigmented
lesions in Asians have reported a PIH risk of around 25%.[30,32,33]
Chan et al.[33] comparedthe use of different types of 532-nm Nd:YAG
lasers in the treatment of facial lentigines in Chinese patients
and found similareffectiveness for the QS Nd:YAG and long-pulsed
Nd:YAG. However, there was a higher risk of
post-operativehyperpigmentation with the QS device. It has been
suggested that unlike the long-pulsed laser that causes tissue
destructionpurely by photothermolysis, the QS Nd:YAG laser, with
its high-energy nanosecond radiation, exhibits both photothermal
andphotomechanical effects. The undesirable photomechanical effect
induces damage to surrounding oxyhemoglobin as well astarget
melanin, resulting in inflammation of superficial vessels, altered
activity of melanocytes, and subsequent PIH.[34]Results from other
studies also support the theory that long-pulsed devices are more
suitable for Asian skin in reducing therisk of PIH.[30,35]
IPL sources emit a broad band of visible light from a
non-coherent filtered flashlamp and produce photothermal
effectsonly.[36] There have been several studies confirming the
effectiveness of IPL in the management of epidermal pigmentationin
Asians. Negishi et al.[35,37] conducted two studies that evaluated
photorejuvenation using IPL. Results from the first studyinvolving
97 Asian patients (cut-off filter 550 nm, 28-32 J/cm2, double-pulse
mode of 2.5-4.0/4.0-5.0 msec, delay time20.0/40.0 msec) showed that
>90% of patients reported a reduction in pigmentation after
three to six treatments at intervalsof 2-3 weeks.[35] The second
study used IPL with an integrated contact cooling system (cut-off
filter 560 nm, 23-27 J/cm2,double-pulse mode of 2.8-3.2/6.0 msec,
delay time 20.0/40.0 msec) and, in this study, 80% of the 73
patients evaluated hada significant reduction in pigmentation after
three to five treatments at intervals of 3-4 weeks.[37] Kawada et
al.[38] evaluated60 patients with solar lentigines and freckles and
reported more than 50% improvement in 68% of these patients
followingthree to five IPL treatments at intervals of 2-3 weeks
(cut-off filter 560 nm, 20-24 J/cm2, 2.6-5.0 msec pulse duration
indouble or triple pulses, delay time 20 msec). Freckles responded
better than lentigines. Interestingly, post-operative PIH wasnot
seen in any of these studies, highlighting the advantage of IPL as
a treatment choice for photorejuvenation in Asianpatients.
A treatment algorithm relating to use of lasers and IPL sources
for the treatment of acquired pigmentary lesions in Asianshas been
put forward by Chan[36] to help physicians weigh up issues such as
cost effectiveness, clinical outcome, andadverse events such as
PIH. This author suggests IPL for patients who demand a low risk of
PIH and who are amenable tohaving several treatment sessions. A
median approach using long-pulsed Nd:YAG may be considered if a
faster outcome isdesired. An aggressive approach using QS lasers
requires only one to two sessions, which make this approach the
mosttime- and cost-effective approach; however, it also carries the
highest risk of PIH and necessitates a downtime period of
1week.
Other means of reducing PIH in Asians include diascopy during
laser therapy to compress and empty dermal vessels inorder to
reduce the risk of dermal vascular damage and hemosiderin
deposition. Kono et al.[39] recently compared theefficacy and
complications seen with use of the QS ruby laser and the
595-nm-long pulsed dye laser (PDL) delivered with acompression
method in the treatment of lentigines. The efficacy was similar in
both groups but there was a much lower riskof PIH in the group
treated with the compression technique. Using a laser or light
source with a shorter wavelength (350-500
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nm) confines the thermal injury to the epidermal layer and is
another means of reducing the risk of PIH.[4]
2.4 Nevus of OtaNevus of Ota is a dermal melanocytic hamartoma
common in Asians and affects about 0.6% of the population.[40]
Clinically,nevus of Ota presents as a bluish hyperpigmentation
along the distribution of the trigeminal nerve. QS ruby, QS
alexandrite,and QS 1064-nm Nd:YAG lasers have all been used to
achieve good therapeutic results.[41] Watanabe and
Takahashi[42]evaluated 114 nevus of Ota patients treated with a QS
ruby laser and reported a good-to-excellent degree of lightening
afterthree or more treatment sessions. Kono et al.[43] confirmed
these findings when they reviewed 101 nevus of Ota patients
12months after they had been treated with a QS ruby laser and found
that 56% reported over 75% clearing and 36% achievedcomplete
clearing. Hypopigmentation was seen in 17% of patients and
hyperpigmentation in 6%. Studies comparing the useof QS alexandrite
with QS 1064-nm Nd:YAG lasers found the former to be better
tolerated but the latter more effective afterthree or more
sessions.[44,45] The risks of hypo- and hyperpigmentation were
similar in both treatment groups, with 15%hypopigmentation and 3%
hyperpigmentation reported at all treated sites. The risk of
recurrence is estimated to be between0.6% and 1.2%,[43] which has
important implications when treating pediatric patients.
2.5 Acquired Bilateral Nevus of Ota-Like Macules or Hori's
MaculesAcquired bilateral nevus of Ota-like macules or Hori's
macules is a condition that affects 0.8% of the Asian population.
Horiet al.[46] described bluish-brown hyperpigmentation typically
affecting the bilateral malar regions, forehead, and temples
ofmiddle-aged women with no mucosal involvement. Histopathologic
findings typically show a circumscribed melanocytosis inthe middle
and upper dermis.[47] The disorder often coexists with other
pigmentary disorders such as melasma andlentigines. QS ruby, QS
alexandrite, and QS 1064-nm Nd:YAG lasers have been shown to be
effective in the treatment ofHori's macules (figure 2).[48-50]
However, shorter treatment intervals and more treatment sessions
appear to be necessaryfor a good result. Transient post-operative
hyperpigmentation is a common adverse event, occurring in the
majority oftreated subjects.[49,50] Permanent hypopigmentation has
been reported after treatment with a QS ruby laser.[48] A
recentstudy has proposed use of a QS 532-nm Nd:YAG laser followed
by a QS 1064-nm Nd:YAG laser to obtain a greater degreeof
improvement.[51]
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Figure 2.
Treatment of Hori's macules using a Q-switched ruby laser: (a)
pre-treatment; (b) post-treatment.
3. Non-Ablative Skin Rejuvenation in AsiansNon-ablative skin
rejuvenation with a laser/light source has gained much popularity
in skin of color due to the lower risk ofcomplications and limited
downtime.[14] Non-ablative skin rejuvenation involves the use of a
laser or light source with acooling device to improve the signs of
photoaging, which include lentigines, telangiectasia, increased
pore size, uneventexture, wrinkles, and skin laxity. Cooling is
particularly important in skin of color as it protects the
epidermis and reduces therisk of erythema and edema, which may lead
to subsequent PIH. Green and yellow lasers/light sources (532-nm
Nd:YAG,585- or 595-nm PDL) target the epidermal pigment and
papillary dermal vessels. Injury to dermal vessels and
microvascularsupply of sebaceous glands reduces telangiectasia and
sebum production, in addition to promoting new collagen
formationduring the healing process.[14,52] Near infra-red and
infra-red lasers/light sources (1064-nm Nd:YAG, 1320-nm
Nd:YAG,1450-nm diode, 1540-nm erbium:glass) together with a cooling
device target water in the dermis and, throughphotothermolysis,
cause a rise in dermal temperature, resulting in collagen
tightening and increased collagen production.[4]Monthly treatments
are required for a good effect (figure 3).
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Figure 3.
Photorejuvenation using non-ablative laser devices: (a)
pre-treatment; (b) post-treatment.
More recently, a combination approach that uses different lasers
and light sources in the same treatment session at monthlyintervals
has been advocated.[14,53] This approach targets different skin
chromophores and means optimal results can beachieved. When a
combination approach is used, a lower fluence should be used for
each device to reduce adverse effectsdue to cumulative heat
generation.
Deep-tissue heating using unipolar radiofrequency and newer
infra-red light sources affect the deep dermis and achieveenhanced
skin tightening. This approach is particularly effective for
elevating the eyebrows, treating peri-orbital wrinkles,
andcontouring the lower face and jawline.[14,54] With effective
cooling, the epidermis is protected and PIH is rare even in
darkerskin types.[55] Unipolar radiofrequency, using multiple
passes at a low fluence, is an effective skin-tightening device
andresults in little discomfort and few complications.[56]
IPL sources that emit radiation in the infra-red spectrum have
also been used to achieve deep-tissue heating withsubsequent skin
tightening. Prolonged exposure with pulse width ranging from 6 to 9
seconds is required to heat up thedeep dermis. Contact cooling is
again used to protect the epidermis and reduce the risk of
PIH.[14]
In patients with more severe degrees of photoaging, fractional
resurfacing can be useful for wrinkle and pigment reductionas well
as acne scarring. By using a high fluence and low density (15 mJ,
1000 MTZ/cm2), dermal collagen remodeling isinduced with minimal
epidermal injury. The newer generation of fractional resurfacing
laser devices allows for changes inspot size with higher energy
and, thereby, permits a greater degree of penetration with a
reduction in bulk tissue heating. Inskin of color, the principle of
minimizing post-treatment erythema in order to reduce the risk of
PIH is a useful one. Hence, a
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reduction in energy and density as well as lengthening of
treatment intervals (2-4 weeks for epidermal lesions, 4-6 weeks
fordermal lesions) can also be helpful in reducing the risk of
PIH.[14]
4. Common Skin Diseases in AsiansA survey of 74 589 Asians over
a 2-year period in Singapore[57] listed the most common diagnoses
as atopic dermatitis,acne, and viral infections. The survey
identified more cases of urticaria in the Chinese, more psoriasis
and alopecia inIndians, and, unsurprisingly, more PIH in Malays and
Indians, who tend to have darker skin compared with the
Chinese.
4.1 Atopic DermatitisAtopic dermatitis (eczema) is a common
presenting complaint in all dermatology clinics. There is some
evidence suggestingthat eczema is more common in the Chinese
population. A survey of the 12-month cumulative incidence of atopic
dermatitisin Chinese, Vietnamese, and White infants born in
Melbourne, VIC, Australia showed that 44% of Chinese, 17%
ofVietnamese, and 21% of White infants were affected.[58] A higher
incidence of atopic dermatitis was also seen in Chineseinfants
compared with White infants living in San Francisco, CA, USA and
Honolulu, HI, USA.[59]
However, a study conducted in Leicester, UK, found that although
there were more referrals of atopic dermatitis to thedermatology
department from the Asian community, the incidence was in fact the
same in the Asian and non-Asiangroups.[60] These investigators
suggested a poor knowledge of atopic dermatitis amongst the Asian
community as thereason for the higher rates of referral.
Interestingly, there were frequent anecdotal reports from Asian
patients of theirdisease resolving when they visited India or
Africa and flaring up on their return to the UK, suggesting an
environment-related influence on disease expression.
Management of atopic dermatitis is similar in the different
ethnic groups, and includes emollients, topical
corticosteroids,topical tacrolimus, phototherapy, oral
antihistamines, and immunosuppressants in resistant cases.[61]
4.2 AcneA population-based prevalence study of acne in Hong Kong
adolescents reported 91.3% of their subjects to be affected.[62]The
majority (52.6%) of the subjects developed scarring and
pigmentation as a result of acne but only 2.4% had consulted
aclinician. 26.6% were also disturbed psychologically by acne and
82.9% by its physical appearance. Topical medicationswere the
mainstay of treatment. The study highlighted the importance of
public education of the management of thisexceedingly common
condition, as well as early and aggressive intervention from
clinicians, in order to prevent serioussequelae such as pigmentary
changes, scarring, and psychological disturbances.
The acne hyperpigmented macule is common in skin of color and
persists for an average of 4 months or longer.[63] Ice-pickscarring
or keloidal scarring may also occur and can have a significant
impact on the self-esteem of affected individuals.
Treatment modalities for acne include topical antibacterials,
retinoids, adapalene, azelaic acid, oral antibacterials,
hormonaltreatments, and oral isotretinoin. Tetracyclines are
effective against acne but can be phototoxic. Strict sun avoidance
andprotection are therefore essential when using tetracyclines,
especially in skin of color. Macrolides such as erythromycin
andclarithromycin are non-phototoxic and should be considered as
first-line antibacterial treatment in Asians.[62] Bleachingagents
such as hydroquinone may be used alone or in combination with other
retinoids and corticosteroids for treatment ofthe acne
hyperpigmented macule.[63]
Ablative laser resurfacing using carbon dioxide and erbi-um:YAG
lasers has been shown to be effective in the treatment ofatrophic
acne scars.[64-66] Clinical improvements of 30-75% can be achieved
for patients with superficial atrophic acnescars. However, this
approach is associated with significant downtime and adverse
effects, which include erythema,hyperpigmentation, and
hypopigmentation, that may be permanent.
Different wavelengths within visible radiation have been used to
treat acne. Blue light causes activation of endogenousporphyrins in
Proprionibacterium acnes and kills the bacteria.[67] However, in
Asian patients, an increase in pigmentationcan occur after
prolonged blue light exposure and this is therefore not an ideal
treatment modality in skin of color.[14] PDLtargeting hemoglobin
has been suggested to be effective in the treatment of inflammatory
acne with few adverse effects.[68]However, inconsistent findings
have been reported and further confirmatory studies are
required.[69] Photodynamic therapy,
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using a variety of visible wavelengths and a number of
photosensitizing dyes, has been used to treat acne.[70,71] A
previousstudy showed a statistically significant clearance of
inflammatory acne by topical aminolevulinic acid (3-hour occlusion)
andred light for at least 20 weeks after four treatments, and for
10 weeks after a single treatment.[72] Significant adverse
effectssuch as transient hyperpigmentation, exfoliation, and
crusting were observed. In Asians, short-contact aminolevulinic
acid(10-hour occlusion) followed by activation using an IPL source
can be effective against acne, with erythema being the
maincomplication.[14]
Infra-red lasers are increasingly being used in the treatment of
acne and acne scarring. Use of a non-ablative 1450-nmdiode laser
with cryogen cooling spray for the treatment of atrophic acne scars
in 57 Asian patients was evaluated by Chuaet al.[73] These
investigators reported mild improvement of 16-20% after four to six
treatments. Conventional single-pass,high-energy (11-12 J/cm2)
treatment was used in this study. Pain, erythema, and marked PIH in
39% of treated patientswere reported. Bernstein[74] recently
published a pilot study demonstrating superiority of low-fluence
(8-11 J/cm2),double-pass 1450-nm diode laser treatment over
conventional treatment. Low-fluence, double-pass therapy reduced
acnecounts and pain to the extent that a topical anesthetic could
be omitted. Recently, we evaluated use of a
low-fluence,multiple-pass approach in the treatment of acne
vulgaris among Chinese patients and found that it was effective in
thosewith inflammatory acne, with a low prevalence of PIH (figure
4).
Figure 4.
Treatment of inflammatory acne with a 1450-nm diode laser: (a)
pre-treatment; (b) post-treatment.
Fractional photothermolysis is particularly effective in the
treatment of acne scarring in skin of color, and indeed this is one
ofthe main indications for its use. However, PIH is a potential
complication of this approach. In a recent retrospective study of37
Chinese patients who underwent fractional resurfacing for acne
scarring and skin rejuvenation, Chan et al.[13] concluded
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that while both energy and density parameters are important
considerations for reducing PIH in Asians, density is ofparticular
importance. These investigators concluded that in order to prevent
PIH, a high-energy and low-density treatment ispreferable. A recent
study in Asian patients by Kono et al.[75] reported similar
findings and demonstrated that patientsatisfaction was also
increased when higher fluence rather than higher density was used.
The importance of adjunctivecooling and lengthening of the
treatment interval to 2-4 weeks for epidermal lesions and 4-6 weeks
for dermal lesions toreduce the risk of PIH has also been
emphasized.[13]
4.3 Hypertrophic and Keloid ScarringIt is well known that
hypertrophic and keloid scars are more common in individuals of
Asian descent than in their Caucasiancounterparts.[76] Both types
of scars are characterized by deposition of collagen and
glycoprotein. However, they differclinically; keloids extend beyond
the original wound whilst hypertrophic scars remain within the
borders of the original wound.
Silicone gels are commonly used with some success for the
treatment of keloids and hypertrophic scars. However, asuccessful
outcome is highly dependent on patients adhering to the treatment
regimen over a long period of time.[76] Theefficacy of
corticosteroid injections in the treatment of keloids and
hypertrophic scars is well established. Corticosteroidshave
anti-inflammatory and vasoconstrictive effects, together with an
anti-mitotic effect on fibroblasts and keratinocytes.[77]The most
commonly used corticosteroid is triamcinolone. This agent is
normally administered intralesionally into the scar, ata
concentration of 10-40 mg/mL, every 4-6 weeks for several months or
until the scar is flattened. Multiple adverse effects,including
atrophy, telangiectasia, and pigmentary changes, can occur.[78,79]
Recently, combined use of intralesionaltriamcinolone and
fluorouracil in the treatment of inflamed hypertrophic scars has
been reported to be effective and canavoid these potential
complications.[80]
The 585-nm PDL appears to be effective in the treatment of
keloid and hypertrophic scars. Vascular proliferation plays a
keyrole in the early phase of scar formation. Through selective
photothermolysis, the light energy emitted from a PDL isabsorbed by
hemoglobin, generating heat and leading to coagulation
necrosis.[81,82] Clinical studies of PDL treatment ofscars have
noted no significant difference in treatment outcomes when minor
variations in fluence were used.[83] However,there was a trend for
lower fluences to be associated with greater improvement.
Manuskiatti and Fitzpatrick[84] evaluated theclinical response of
keloidal and hypertrophic scars after treatment with an
intralesional corticosteroid alone or combinedwith fluorouracil,
fluorouracil alone, and the 585-nm flashlamp-pumped PDL. They found
a significant clinical improvement inall treated segments, but no
significant difference between the different treatment modalities.
Intralesional formulas resultedin faster resolution of scar
compared with PDL. Scar texture (erythema and pliability) responded
better to PDL. Anotherstudy that evaluated use of PDL in 29 Chinese
patients with hypertrophic scars showed that apart from an
improvement inpruritus, there was no significant difference in scar
thickness between the treatment and control groups.[85] However,
asupra-purpuric dose was used and excessive injury may have led to
the poorer observed clinical outcome. Post-operativepurpura
persisting for 7-10 days has also been reported following PDL use
in other studies.[86] These findings suggest thatearly treatment
with a combination of intralesional triamcinolone and fluorouracil
to flatten the scar, followed by sub-purpuricPDL to improve color,
texture, and pruritus, may be the most effective approach.
4.4 PsoriasisPsoriasis was the seventh most common skin
condition in a large Asian patient survey conducted in
Singapore.[57] However,psoriasis is more commonly seen in
Caucasians than in Asians and Africans, and is very rare in Native
Americans andHispanics.[87] Treatments for psoriasis include
topical corticosteroids, tar, calcipotriene (calcipotriol), UVB,
psoralen plusUVA (PUVA), and other oral immunosuppressants such as
methotrexate, acitretin, and cyclosporine (ciclosporin).
Aninteresting study examining 4294 long-term PUVA patients in
Japan, Korea, Thailand, Egypt, and Tunisia found no
apparentincreased risk of non-melanoma skin cancer with long-term
PUVA therapy in Asian patients.[88] This is in contrast to
theCaucasian experience, for which strict PUVA therapy guidelines
exist because of the increased risk of cutaneousmalignancies.
Phototherapy is therefore a useful long-term treatment option for
Asians with psoriasis and other skinconditions such as vitiligo,
cutaneous T-cell lymphoma, and atopic dermatitis.
4.5 Primary Cutaneous AmyloidosisPrimary cutaneous amyloidosis
presents most commonly as either lichen or macular amyloidosis. It
is a condition commonlyseen in southeast Asia and some South
American countries.[89] Lichen amyloidosis is a persistent,
pruritic, popular, andplaque-like eruption with a predilection for
the shins and extensor arms, and is most commonly seen amongst the
Chinese.
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Macular amyloidosis presents as small brown macules coalescing
into patches distributed typically in a rippled, symmetricpattern
on the upper back, limbs, chest, and buttocks. It most commonly
presents together with lichen amyloidoisis asbiphasic amyloidosis.
Histologically, deposits of amyloid are seen in the papillary
dermis, and the diagnosis can easily beconfirmed by staining the
amyloid red using congo red or metachromatically using crystal
violet or toluidine blue.[90,91]
Anosacral amyloidosis is a rare form of cutaneous amyloidosis
reported previously in Chinese and Japanese patientsonly.[92] It
presents as pruritic, well demarcated, brownish patches or plaques
fanning out in lines from the anus to the sacralregion. It is more
common in men. This condition can be easily mistaken as lichen
simplex chronicus, PIH, and tinea crurisand a skin biopsy should be
carried out if the diagnosis is in doubt.
Treatment of cutaneous amyloidosis can be difficult. Reducing
friction to the skin is important. Topical
high-potencycorticosteroids, oral retinoids, and cyclophosphamide
have also been reported to be beneficial.[93]
4.6 Kawasaki DiseaseKawasaki disease is an acute febrile
vasculitis that may lead to coronary artery abnormalities. It has a
much higherincidence in Asian children.[94,95] The diagnostic
criteria include fever (>38.3C) of 5 days duration plus at least
four of thefollowing five criteria: (i) peripheral extremity
changes; (ii) polymorphous exanthem; (iii) non-purulent bilateral
conjunctivalinjection; (iv) changes in the lips and oral cavity,
such as erythema and strawberry tongue; and (v) acute,
non-purulentcervical adenopathy.[96] The polymorphic cutaneous
eruption lasts 10-20 days and then subsides. One to two percent
ofpatients may die of a myocardial infarction soon after apparent
recovery from the acute illness.[91]
Diagnosis of Kawasaki disease is very important because steps to
prevent coronary aneurysm and myocardial infarction canthen be
taken. All patients should be hospitalized during the acute febrile
stage, and a baseline echocardiogramperformed.[91] A single dose of
intravenous -globulin at 2 g/kg should be given over a 10- to
12-hour infusion. Aspirin(acetylsalicylic acid) should also be
started at 100 mg/kg/day until the fever is controlled or until day
14 of the illness,followed by 5-10 mg/kg/day until the
sedimentation rate and platelet count are normal. The patient
should have a repeatechocardiogram 3-4 weeks after onset of fever.
If both echocardiograms are normal, no further imaging needs to be
done.Patients should, however, be followed up periodically. The
disease is self-limiting and the prognosis for most children is
goodif an early diagnosis is made.[91] Studies have shown that a
delay in diagnosis of >10 days or occurrence in infants aged 3
mm and 37% of these 9 mm. A study from Japan also reported the foot
as the most
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commonly affected area with 50% being the acral lentiginous
melanoma type.[100] A large percentage also presented withadvanced
disease, with 30% demonstrating metastases and a poor
prognosis.
Figure 5.
Melanoma on the plantar aspect of the foot.
Delays in diagnosis and treatment of melanoma are possibly due
to lack of public and physician education and preventativescreening
programs in Asian countries. There is often a misconception that
darker skinned individuals do not develop skincancer. The sites of
melanoma occurrence are also unexpected and difficult for patients
to examine. In addition, acral tumorstend to be intrinsically more
aggressive and therefore present at a later stage, leading to
poorer prognosis.[102] Bothphysicians and patients therefore need
to maintain a high index of suspicion for melanomas regardless of
ethnicity andparticular attention needs to be paid to palms, soles,
fingers, toes, subungual areas, and mucosal surfaces in Asian
patients.
5.2 Non-Melanoma Skin CancerBasal cell carcinoma (BCC), followed
by squamous cell carcinoma (SCC), are the most common skin cancers
in Chineseand Japanese individuals.[98,100,103] In Singapore, the
incidence of BCC increased at a rate of 2.8% per year between
1968and 1997, while the rates of SCC decreased by 0.9% yearly.[98]
Chinese individuals, who are generally of lighter skin type,were
twice as likely to develop BCC and SCC as the darker skinned Malays
and Indians. In a survey conducted between1983 and 1987 of the
Japanese population living in sunny Hawaii, USA, the incidence per
100 000 was 60 for BCC, 48 forSCC, and 22 for Bowen disease.[104]
The incidence of BCC in Japanese individuals living in native Japan
was much lower,at 16.5 per 100 000, demonstrating the harmful
effects of UV radiation.[105]
Known risk factors for BCC and SCC include UV exposure,
Fitzpatrick skin types I-III, male sex, chemical and
radiationexposure, burn or scar injuries, genetic disorders such as
xeroderma pigmentosum, Gorlin syndrome, immunosuppression,and
infection with human papillomavirus.[106] Photoprotection and early
diagnosis can often lead to a better outcome.
5.3 Cutaneous T-Cell LymphomaMycosis fungoides or cutaneous
T-cell lymphoma is the fourth most common skin cancer amongst the
Japanese.[106]Hypopigmented mycosis fungoides, with ill-defined,
often pruritic, hypopigmented macules and patches, tends to present
ina younger patient population and only in skin of color (figure
6).[107,108] The disorder can often be mistaken for
vitiligo,pityriasis alba, tinea versicolor, or post-inflammatory
hypopigmentation. Misdiagnosis can delay treatment. There is
usually agood response to PUVA, UVB phototherapy, or topical
mechlorethamine (chlormethine), but recurrences are common.
Theoverall prognosis is good.[109]
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Figure 6.
Hypopigmented mycosis fungoides.
6. Other Esthetic ProceduresOver the last few decades, there has
been a surge of interest in, and performance of, esthetic
enhancement procedures inAsian countries. There has also been a
greater cultural acceptance of esthetic modification and skin
rejuvenation usingnon-surgical techniques to reduce the stigmata of
aging.
6.1 Botulinum Toxin Type AAlthough wrinkling occurs later in
Asians compared with Caucasians, rhytides appear in the same
predictable manner as aresult of repetitive action of facial
musculature. Botulinum toxin type A (Botox; Allergan, Irvine, CA,
USA) blocks the releaseof the neurotransmitter acetylcholine at the
neuromuscular junction, thereby causing paralysis of the affected
muscle. It wasfirst reported to be an effective treatment of fine
facial wrinkles in the 1990s.[110] Anh et al.[111] found no
difference in thelongevity of treatment and the amount of toxin
required for Asian skin despite the increased dermal thickness and
collagencontent of the skin of Asian people. Common injection sites
for elimination of facial hyperkinetic wrinkles include the
lateralcanthal area, glabellar area, forehead, and nasal dorsum.
Repeated injections are generally required every 4-6
months.[112]Flynn et al.[113] showed that botulinum toxin injected
concomitantly into lateral and infra-orbital areas results in
successfulimprovement in infra and peri-orbital wrinkles and also
widens the eye. The results were especially notable in Asians.
Botulinum toxin can also be used to reduce a prominent
mandibular angle, the so-called 'square jaw,' in Asians. Kim
etal.[114] followed up 383 patients who received botulinum toxin
injection (100-140 U) [Dysport; Ipsen Ltd, Slough, UK] intothe
inferior masseter borders and found an average 31% reduction in
masseter hypertrophy on ultrasound 3 months aftertreatment (figure
7). Ninety-three percent of patients were positive about the
outcome. Re-injection was required after 4-7months. Mild fatigue
after vigorous chewing was the main complaint, followed by
transient awkwardness when smiling. Morerecently, botulinum toxin A
has also been used for contouring of enlarged gastrocnemius muscles
with no functionaldisabilities. The improvement was well maintained
for 6 months.[115,116]
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Figure 7.
Use of botulinum toxin type A for masseter hypertrophy: (a)
pre-treatment; (b) post-treatment.
6.2 Soft Tissue Fillers for Tissue AugmentationAsian patients,
like their Western counterparts, are increasingly seeking a more
youthful face with fewer wrinkles and fullerfeatures. Fillers are
therefore increasingly being used in the management of facial
lines, lip augmentation, and treatment ofdistensible atrophic
facial scarring. Fillers can be divided into two groups;
biodegradable materials that are used fortemporary augmentation,
such as hyaluronic acid and bovine collagen, or non-biodegradable
materials, such as silicon oil orpolymethylmethacrylate in
combination with bovine collagen, which require some time to obtain
a permanent result becauseof encapsulation. The ideal filler is a
non-allergenic, non-toxic, non-migratory replacement for lost
collagen or subcutaneousfat. It should be easy to use with a direct
result and no adverse effects.
Skin reactions to bovine serum collagen have been well
documented, and double skin testing is recommended.[117] Theremay
also be a risk of variant Creutzfeldt-Jakob disease or other
pathogenic infections when materials derived from animalorigins are
used. Hyaluronic acid fillers such as Restylane (Q-Med, Uppsala,
Sweden) and Hylaform (Biomatrix, Inc,Ridgefield, NJ, USA) are
marketed as having minimal allergy risk and not requiring skin
testing. Studies comparing theefficacy and tolerability of
Restylane with those of the bovine collagen Zyplast (McGhan Medical
Inc., Santa Barbara, CA,USA) have found Restylane to be superior in
effectiveness and longevity.[118] However, 0.42% of a study
population of 709developed delayed skin reactions. Nevertheless,
this is a much lower rate than that reported for bovine collagen,
which isbetween 3% and 4%.[117,119] Hyaluronidase can resolve any
undesirable effects of Restylane.[120]
Artecoll (Rofil Medical International, Breda, the Netherlands)
is used as a long-lasting, deep dermal augmenting agent. It
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consists of microspheres of polymerized methylmethecrylate in a
bovine collagen vehicle. A randomized controlled,multicenter,
clinical trial of 251 subjects reported Artecoll to be superior in
terms of facial fold reduction and patientsatisfaction after 6
months compared with collagen.[121] Early lump formation,
especially in the lips, may occur in patientstreated with Artecoll
and is thought to be due to excess movement prior to full
encapsulation by host fibrin and fibrinogen.Talking should be
minimized in the early days or concurrent use of botulinum toxin
may be considered. Granuloma formationis very rare and usually
occurs 6-24 months after injection. The granulomas resolve
spontaneously after 4-6 years.Intralesional triamcinolone may speed
up the process.[122,123] A good technique is important for reducing
complications.
Poly-L-lactic acid (New-Fill; Ashford Aesthetics Inc., Brussels,
Belgium or Sculptra; Aventis Pharmaceuticals,Bridgewater, NJ, USA)
has been used for the correction of HIV-related facial lipoatrophy
and cosmetic rejuvenation ofnon-HIV patients.[124] Temporary edema
and bruising are common adverse effects. However, a report by
Beljaards et al.[125]described three cases with serious giant cell
granulomatous reactions after use of New-Fill or Sculptra.
Intralesionalcorticosteroid therapy and topical imiquimod were
moderately effective for resolving these reactions.
7. Regulatory IssuesThere is a lack of regulation of the use of
lasers and esthetic procedures in most Asian countries. As a
result, beauticiansworking at beauty parlours and medical spas are
offering esthetic enhancement procedures with no formal training
and posea significant risk to their clients. Strict policies should
be in place to restrict the use of lasers and the performance of
estheticprocedures to medical specialists such as dermatologists
and plastic surgeons for the safety of patients.
8. ConclusionWith evolving demographics, there will be an
increasing number of Asians presenting to dermatology outpatient
clinics.Increased epidermal melanin is photoprotective against UV
damage. However, it is also responsible for causing
severalpigmentary conditions that can be particularly troublesome
to Asians in their quest for fair porcelain skin. Management
ofAsian skin requires different considerations than when dealing
with Caucasian skin, and development of laser technologythat
protects epidermal melanin from damage makes laser surgery
increasingly safe in skin of color. Awareness ofcutaneous disorders
that are common or particular to skin of color is also important,
especially for clinicians who work inareas with a large Asian
community.
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Acknowledgments
No sources of funding were used to assist in the preparation of
this review. Dr Chan has acted as a consultant to Palomar,Danish
Dermatologic Development, and Thermage; has been an Advisory Board
member for Laserscope, CureLight,Johnson & Johnson, and
Galderma; has received clinical trial grants from Palomar, Danish
Dermatologic Development,Candela, and Syneron Medical; and holds
stock in Reliant Technologies and CureLight. Dr Ho has no conflicts
of interestthat are directly relevant to the content of this
review.
Reprint Address
Dr Henry H.L. Chan, 13/F Club Lusitano, 16 Ice House Street,
Central, Hong Kong SAR, China. E-mail:[email protected]
Am J Clin Dermatol. 2009;10(3):153-168. 2009 Adis Data
Information BV
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