Laser Surgery in Dark Skin

80 March • April 2003

Although challenging, effective laser surgery inpatients with darker skin tones can be achieveddespite a higher inherent risk of untoward sideeffects. While the incidence of undesirable postoper-ative sequelae has decreased with the developmentof advanced laser technology and individualizedtreatment parameters, these risks may never be elim-inated completely. Consequently, thorough patientpreoperative preparation and education regardingthe risks of cutaneous laser therapy will remain anessential component of treatment in darkly pig-mented patients. In the future, as more refined lasertechniques evolve, the ability to safely and effective-ly treat these patients will improve. (SKINmed.2003;2:80–85) ©2003 Le Jacq Communications, Inc.

The safe and effective laser treatment ofpatients with darker skin tones presentsa challenge to the laser surgeon and is

becoming more frequently encountered as thepatient population continues to increase andbecome more ethnically diverse. Population sta-tistics of the United States reveal dramaticallyshifting demographics in the past decade.Between 1990 and 2000, Hispanics and Asiansaccounted for 40% of the total growth of the USpopulation, African Americans for 12%, andnon-Hispanic Caucasians for slightly over 2%.1

In 2000, the total number of individuals in theUnited States with skin of color was approxi-mately 85 million.1 Despite the increaseddemand for dermatologic laser surgery by Asians,Hispanics, and African Americans, most of thecurrent literature remains devoted to examininglaser procedures performed on individuals withfair skin tones (skin phototypes I–II) and proto-cols have largely been defined on the basis of themore extensive clinical experience that has accu-mulated surrounding these patients.

Due to its unusually wide absorption spec-trum ranging from 250–1200 nm, all visible-

light and near-infrared dermatologic laserscurrently in use can specifically targetmelanin. Nonspecific energy absorption byrelatively large quantities of melanin in thebasal layer of the epidermis can increaseunintended nonspecific thermal injury andlead to a higher risk of untoward side effectsincluding permanent dyspigmentation, tex-tural changes, focal atrophy, and scarring inthe darkly pigmented patient. Moreover,competitive absorption by epidermalmelanin substantially decreases the totalamount of energy reaching deeper dermallesions, rendering it more difficult to achievethe degree of tissue destruction necessary toaffect the desired clinical result. Treatmentparameters, therefore, must be carefully con-sidered when performing laser surgery onpatients with darker skin phototypes.

Although difficult, effective laser therapy inpatients with darker skin phototypes can beachieved,2–7 since the absorption coefficientof melanin decreases exponentially as wave-lengths increase. Illustrating this principle,epidermal melanin absorbs approximatelyfour times as much energy when irradiatedby a 694 nm ruby laser as when exposed tothe 1064 nm beam generated by theneodymium:yttrium-aluminum-garnet (Nd:YAG) laser, thus allowing greater penetrationof the longer wavelength.8 Therefore lasersystems generating wavelengths that are lessefficiently absorbed by endogenous melanincan often provide a greater margin of safetywhile still allowing the laser surgeon toachieve satisfactory results.

When determining a treatment protocol for anindividual patient, power level is at least asimportant as the laser wavelength chosen whentreating darker skin, since highly melanized skin

From the Washington Instituteof Dermatologic Laser Surgery,Washington, DC

Address for correspondence:Tina S. Alster, MD,Washington Institute ofDermatologic Laser Surgery,2311 M Street N.W., Suite200, Washington, DC 20037E-mail: [email protected]

Laser Surgery in Dark SkinTina S. Alster, MD; Elizabeth L. Tanzi, MD

R e v i e w

81March • April 2003

L a s e r S u r g e r y i n D a r k S k i n

absorbs electromagnetic energy much more effi-ciently than does fair skin. For example, skinphototype VI may absorb as much as 40% moreenergy when irradiated by a visible light laserthan does class I or II skin when fluence levelsand exposure duration remain constant.9 Thus,conservative power settings (the minimal thresh-old fluences necessary to produce the desired tis-sue effect in a given individual as determinedthrough irradiation test spots) should beemployed initially to minimize the extent of col-lateral tissue damage. Clearly, a prudentapproach to treatment is far preferable to incur-ring the risk of irreparable tissue destructionresulting from excessive thermal injury, even ifthis may necessitate multiple laser treatments inorder to achieve maximal clinical results.10

Pigment-Specific LasersPigment-specific laser technology generatesgreen, red, or near-infrared light to selectively tar-get intracellular melanosomes or tattoo pigment.Pigment-specific lasers are also used to eradicateunwanted hair by damaging follicular structuresin which melanin is heavily concentrated.

Q-switched systems generating nanosecond (ns)pulses, which are substantially shorter than the10–100 ns thermal relaxation time ofmelanosomes, represent the safest means fortreating pigmented lesions in dark skin. Q-switched systems currently available include the532 nm frequency-doubled Nd:YAG, 694 nmruby, 755 nm alexandrite, and 1064 nm Nd:YAGlasers. Although melanin absorbs energythroughout this range of wavelengths, its absorp-tion peaks lie in the ultraviolet range, withdecreased absorption capacity at the longestwavelengths. Thus, the far infrared wavelengthsgenerated by the alexandrite and Nd:YAG lasersystems are less efficiently absorbed by epidermalmelanin, which limits the extent of unwantedthermal injury to nontargeted tissues of the epi-dermis and upper papillary dermis. This, in turn,allows for deeper dermal penetration, makingthe effective treatment of pigmented dermallesions and hair follicles possible. Whether tar-geting superficial epidermal lesions such aslentigines, ephelides, café-au-lait macules, orlesions with a deep dermal component such asnevus of Ota, melanocytic nevi, or nevus spilus,treatment should be initiated at threshold flu-ences (the minimum fluence necessary to pro-duce immediate lesional whitening signaling thedestruction of intracellular melanosomes). If theclinical threshold is exceeded, epidermal exfolia-

tion and pinpoint bleeding ensues, resulting inblistering, possible temporary or permanenthypopigmentation, and perhaps even skin tex-tural changes or scarring.8,10

Of the pigmented lesions that disproportionate-ly affect ethnic groups with darker phototypes,nevi of Ota have proved especially amenable totreatment with Q-switched ruby, alexandrite,and Nd:YAG lasers.11–13 Of these systems, thealexandrite laser appears to offer distinct advan-tages over othermodalities as itslonger wavelengthproduces less epi-dermal damagethan does the rubylaser and, since itrequires lower flu-ences than does theNd:YAG, less tissue splatter is produced intraop-eratively.13 (Figures 1 A & B)

Because multiple different pigments may be pres-ent in a tattoo, effective treatment can requirethe use of wavelengths throughout the visibleand near-infrared spectrum. Tattoos mayrespond unpredictably to laser treatment notonly because their chemical compositions are

Although difficult,effective laser therapyin patients with darkerskin phototypes can be

achieved.

“”

Figure 1A. Nevus of Ota in apatient with type III/IV skin

Figure 1B. Clearing notedafter five Q-switched 755 nmalexandrite laser treatments

highly variable, but also because they can beplaced in the deep dermis. Treatment is more dif-ficult and unpredictable in patients with darkerskin phototypes because of the presence of sig-nificant amounts of epidermal melanin thatabsorbs the laser energy. As described previously,systems that generate energy characterized bylonger wavelengths cause less collateral epider-mal damage and penetrate more deeply, afford-ing a safer and usually more effective form oftreatment. Although the Q-switched 694 nmruby laser is highly efficacious in removing blackand blue tattoo pigments, its wavelength isstrongly absorbed by epidermal melanin and itspotential for inducing long-term dyspigmenta-tion or other untoward side effects is relativelyhigh in patients with darker skin tones. Thus, theQ-switched Nd:YAG (1064 nm) or alexandrite(755 nm) laser would be a better choice for treat-ing blue and black tattoo pigments in darker skinsince its energy is less well absorbed by epidermalmelanin. Epidermal ablation with a resurfacinglaser may enhance the safety and effectiveness oftattoo removal in patients with darker photo-types by eliminating the problem of competitivemelanin absorption.14

The combination of longer wavelengths, activeepidermal cooling, and longer pulse durationsprovided by the most advanced laser technolo-gy has decreased the side effects following

laser-assisted hair removal in patients withdarker skin tones.15–23 Several pigment-specificlaser systems with relatively long (millisecond)pulse durations have demonstrated safety andefficacy in darker skin phototypes, includingthe 755 nm alexandrite,17–19 810 nm diode,20,21

and 1064 nm Nd:YAG.23,24 Intense pulsed-lighttreatment of hirsutism in patients with darkerskin phototypes may also be possible; however,studies have been limited.22 One study24

demonstrated significant long-term hair reduc-tion after a series of 3 monthly long-pulsed1064 Nd:YAG laser treatments in 20 womenwith skin phototypes IV–VI. (Figures 2 A & B)Adverse effects were limited to transient pig-mentary alteration without fibrosis or scar-ring.24 Pseudofolliculitis barbae, a conditionwith a high incidence in the African Americanpopulation, has also been shown to respondfavorably to laser-assisted hair removal withminimal untoward sequelae.20,21

Vascular-Specific LasersVascular-specific laser systems include a widearray of Q-switched, pulsed, and quasicontinu-ous wave lasers generating green or yellow lightwith wavelengths ranging from 532–600 nm.Since 577 nm represents a major absorption peakof oxyhemoglobin, the 585 nm flashlamp-pumped pulsed dye laser (PDL) has proved to bethe most vascular-specific. For the treatment ofport-wine stains, hemangiomas, and facialtelangiectasias, the 585 PDL has garnered thebest clinical track record for both effectivenessand safety, regardless of patient skin phototype.This system has also proved effective in thetreatment of hypertrophic scars and keloidswhich occur more frequently among individualswith darker skin tones.25 (Figures 3 A & B)Transient postinflammatory hyperpigmentationis the most common side effect of PDL treat-ment. Although patients with darker skin photo-types are more prone than those with fair skin ofdeveloping pigmentary changes after PDL treat-ment,26 skin cooling techniques can reduce therisk of dyspigmentation.27 Hyperpigmentationoften resolves within 2–3 months, as does tran-sient hypopigmentation. Permanent hypopig-mentation and scarring are rare. The side effectprofiles for the frequency-doubled Nd:YAG andpotassium titanyl phosphate (KTP) lasers are sim-ilar, but side effects resulting from nonspecificepidermal injury in darker skinned patients aregenerally more common.28 Investigators foundthat while the 578 nm copper vapor laser couldimprove port-wine stains in patients with skin



Figure 2A. Dark terminal hairon the chin in a patient with type V skin

Figure 2B. Reduced hair seen 6 months after third long-pulsed1064 nm Nd:YAG laser treatment

phototypes III–IV, a significant degree of epider-mal injury resulted from laser treatment.2,3

In 1998, long-pulsed (millisecond) 1064 nmlasers were introduced in an effort to targetviolaceous leg telangiectasia and large calibersubcutaneous reticular veins.29 The benefit ofthis wavelength is deep penetration of itsenergy due to relatively low absorption bymelanin, thus effecting safe treatment inpatients with darker skin tones. These milli-second-domain 1064 nm lasers may offer aviable treatment option for vascular birth-marks in patients with darker skin photo-types in the future.30

Ablative and Nonablative LaserSkin ResurfacingCutaneous laser resurfacing can provide aneffective means for improving the appear-ance of diffuse dyschromia, photoinducedrhytides, and atrophic scarring in patientswith darker skin phototypes. Several reportsdocument the long-term safety of the high-energy, pulsed and scanned carbon dioxide(CO2) and short- and long-pulsed erbium:YAG for the treatment of more darkly pig-mented patients.31–35 Although the degree ofcosmetic improvement possible followingablative laser skin resurfacing in patientswith skin phototypes I and II may not beattainable in patients with darker skin tones,studies have reported a high rate of satisfac-tion in this population.4,5 Preoperative skinpreparation and meticulous postoperativecare are essential for success when treatingpatients with darker skin phototypes.Effective patient education and comprehen-sive information about the most commonlyexperienced side effects, especially postin-flammatory hyperpigmentation, is crucial inthe management of patients with darker skintones. While transient hyperpigmentation isthe most commonly experienced side effectafter laser skin resurfacing (affecting approxi-mately one third of all patients), the inci-dence rises to 68%–100% among patientswith skin phototypes greater than typeIII.33–35 (Figures 4 A & B)

Of particular importance for individuals withdarker complexions, especially those living inregions where ultraviolet radiation is mostintense, is the strict avoidance of excessivesun exposure and the consistent use of full-spectrum sunscreens both before and after

laser treatment. Ideally, individuals withdarker complexions should follow pretreat-ment regimens that include consistent sun-



Figure 3A. Hypertrophic scarbefore treatment

Figure 3B. Improvement in scarcolor and bulk after four 585 nmpulsed dye laser treatments

Figure 4A. Hyperpigmentationapparent 4 weeks after carbondioxide laser resurfacing for acnescars in a patient with skin phototype IV

Figure 4B. Resolution of hyper-pigmentation 10 weeks after dailyuse of topical hydroquinone andglycolic acid creams

screen use for longer periods than is neces-sary for those with fair skin tones. Sunscreenuse (sun protection factor ≥30) should be ini-tiated at least 3–4 months before surgery andreinstituted as soon as possible postoperative-ly.36 Although they do not diminish [AU:WORD ALTERED. DIMINATE NOT AWORD] the risk of postinflammatory hyperpig-mentation in patients with darker skin photo-types, some presurgical topical treatments mayenhance the eventual postoperative results.Investigators37 have found that, contrary to theassumptions of many clinicians, pretreatmentwith hydroquinone, tretinoin, or glycolic aciddoes not decrease the incidence of hyperpig-mentation following ablative laser resurfacing inany skin phototype. But pretreatment withretinoic acid does appear to speed re-epithelial-ization rates and it can also reduce rates ofmelanin production after being reinstituted

after the initial stage of healing is completed andthe skin has regained its tolerance.38,39 Thus,even if it does not decrease the actual incidenceof post-treatment hyperpigmentation, retinoicacid may still reduce its severity and duration,factors of critical importance for patients withdarker skin tones.

Newer dermal collagen remodeling optionsincluding nonablative lasers may prove a moresatisfactory compromise between efficacy andsafety in patients with darker skin tones. A cool-ing device protects the epidermis at the sametime as laser energy is absorbed in the upper der-mis. While nonablative lasers have not yetaccrued a long history of clinical use in darker-complected patients, it is reasonable to anticipatethat they may offer benefit to patients whodesire clinical improvement with decreased riskof postoperative dyspigmentation.



REFERENCES1 Taylor SC, Cook-Bolden F. Defining skin of color.

Cutis. 2002;69:435–437.2 Chung JH, Koh WS, Lee DY, et al. Copper vapor

laser treatment of port-wine stains in brown skin.Australas J Dermatol. 1997;38:15–21.

3 Chung JH, Koh WS, Youn JL. Histologicalresponses of port-wine stains in brown skin after578 nm copper vapor laser treatment. Lasers SurgMed. 1996;18:358–366.

4 Kim JW, Lee JO. Skin resurfacing with laser inAsians. Aesthetic Plast Surg. 1997;21:115–117.

5 Ruiz-Esparza J, Gomez JMB, de la Torre OLG, etal. Ultrapulse laser skin resurfacing in Hispanicpatients: a prospective study of 36 individuals.Dermatol Surg. 1998;24:123–129.

6 Ho C, Nguyen Q, Lowe NJ, et al. Laser resurfacingin pigmented skin. Dermatol Surg. 1995;21:1035–1037.

7 Baba T, Narumi H, Hanada K, et al. Successfultreatment of dark-colored epidermal nevus withruby laser. J Dermatol. 1995;22:567–570.

8 Macedo O, Alster TS. Laser treatment of darkerskin tones: a practical approach. Dermatol Ther.2000;13:114–126.

9 Anderson RR. Laser-tissue interactions in derma-tology. In: Arndt KA, Dover JS, Olbricht SM, eds.Lasers in Cutaneous and Aesthetic Surgery.Philadelphia, PA: Lippincott-Raven; 1997:28.

10 Alster TS. Laser treatment of darker skin photo-types: recent progress. Cosmetic Dermatol. 1999:13–16.

11 Ueda S, Isoda M, Imayama S. Response of naevusof Ota to Q-switched ruby laser treatment accord-ing to lesion colour. Br J Dermatol. 2000;142:77–83.

12 Chan HH, Ying SY, Ho WS, et al. An in vivo trialcomparing the clinical efficacy and complicationsof Q-switched 755 nm alexandrite and Q-switched1064 nm Nd:YAG lasers in the treatment of nevusof Ota. Dermatol Surg. 2000;26:919–922.

13 Alster TS, Williams CM. Treatment of nevus ofOta by the Q-switched alexandrite laser. DermatolSurg. 1995;21:592–596.

14 Kilmer SL. Laser treatment of tattoos. In: Alster

TS, Apfelberg DB, eds. Cosmetic Laser Surgery: APractitioner’s Guide. 2nd ed. New York, NY: Wiley-Liss; 1999:289–303.

15 Nanni CA, Alster TS. Complications of laser-assisted hair removal using Q-switched Nd:YAG,long-pulsed ruby, and long-pulsed alexandritelasers. J Am Acad Dermatol. 1999;41:165–171.

16 Chana JS, Grobbelaar AO. The long-term resultsof ruby laser depilation in a consecutive series of346 patients. Plast Reconstr Surg. 2002;110:254–260.

17 Lu SY, Lee CC, Wu YY. Hair removal by long-pulse alexandrite laser in oriental patients. AnnPlast Surg. 2001;47:404–411.

18 Garcia C, Alamoudi H, Nakib M, et al.Alexandrite laser hair removal is safe forFitzpatrick skin types IV–VI. Dermatol Surg. 2000;26:130–134.

19 Handrick C, Alster TS. Comparison of long-pulsed diode and long-pulsed alexandrite lasersfor hair removal: a long-term clinical and histo-logic study. Dermatol Surg. 2001;27:622–626.

20 Yamauchi PS, Kelly PA, Lask GP. Treatment ofpseudofolliculitis barbae with the diode laser. JCutan Laser Ther. 1999;1:109–111.

21 Greppi I. Diode laser hair removal of the blackpatient. Lasers Surg Med. 2001;28:150–155.

22 Johnson F, Dovale M. Intense pulsed light treat-ment of hirsutism: case reports of skin photo-types V and VI. J Cutan Laser Ther. 1999;1:233–237.

23 Goldberg DJ, Silapunt S. Histologic evaluation ofa millisecond Nd:YAG laser for hair removal.Lasers Surg Med. 2001;28:159–161.

24 Alster TS, Bryan H, Williams CM. Long-pulsedNd:YAG laser-assisted hair removal in pigmentedskin. Arch Dermatol. 2001;137:885–889.

25 Alster TS, Nanni CA. Pulsed dye laser treatmentof hypertrophic burn scars. Plast Reconstr Surg.1998;102:2190–2195.

26 Ho WS, Chan HH, Ying SY, et al. Laser treatmentof congenital facial port-wine stains: long-termefficacy and complications in Chinese patients.Lasers Surg Med. 2002;30:44–47.

27 Chang CJ, Nelson JS. Cryogen spray cooling andhigher fluence pulsed dye laser treatmentimprove port-wine stain clearance while mini-mizing epidermal damage. Dermatol Surg. 1999;25:767–772.

28 West TB, Alster TS. Comparison of the long-pulsedye (590–595) and KTP (532 nm) lasers in thetreatment of facial and leg telangiectasias.Dermatol Surg. 1998;24:221–226.

29 Weiss RA, Dover JS. Laser surgery of leg veins.Dermatol Clin. 2002;1:19–36.

30 Dover JS, Arndt KA. New approaches to the treat-ment of vascular lesions. Lasers Surg Med. 2000;26:158–163.

31 Alster TS, Nanni CA, Williams CM. Comparisonof four carbon dioxide resurfacing lasers: a clini-cal and histopathological evaluation. DermatolSurg. 1999;25:153–159.

32 Ruiz-Esparza J. Long-term effects of one generalpass laser resurfacing: a look at dermal tighteningand skin quality. Dermatol Surg. 1999;25:169–174.

33 Sriprachya-Anunt S, Marchell NL, Fitzpatrick RE, et

al. Facial resurfacing in patients with Fitzpatrickskin type IV. Lasers Surg Med. 2002;30:86–92.

34 Tanzi EL, Alster TS. Treatment of atrophic facial scarswith a dual-mode erbium:YAG laser. Dermatol Surg.2002;28:551–555.

35 Tanzi EL, Alster TS. Variable-pulsed erbium:YAGlaser skin resurfacing: extended experience with50 patients. Plast Reconstr Surg. 2003;111:6.

36 Alster TS. Preoperative patient considerations. In:Alster TS. Manual of Cutaneous Laser Techniques.2nd ed. Philadelphia, PA: Lippincott Williams &Wilkins; 2000:13–32.

37 West TB, Alster TS. Effect of pretreatment on theincidence of hyperpigmentation following cuta-neous CO2 laser resurfacing. Dermatol Surg. 1999;25:15–17.

38 McDonald WS, Beasly D, Jones C. Retinoic acidand CO2 laser resurfacing. Plast Reconstr Surg.1999;7:2229–2235.

39 Alster TS. Combined laser resurfacing andtretinoin treatment of facial rhytides. CosmeticDermatol. 1997;11:39–42.



BenzaClin Topical Gel (clindamycin–benzoyl peroxide gel)

BenzaClin Topical Gel (Dermik Laboratories), a combina-tion treatment containing clindamycin phosphate andbenzoyl peroxide, is used for the topical treatment of acnevulgaris. Individually, each component has been shown tobe active against Propionibacterium acnes, an anaerobefound in sebaceous follicles and comedones. The antibac-terial action of benzoyl peroxide is believed to be due tothe release of active oxygen. Benzoyl peroxide may alsohave keratolytic, desquamative, and antiseborrheic effects.The antimicrobial activity of clindamycin may help inreducing inflammatory lesions.

In two well-controlled studies, clindamycin-benzoylperoxide gel was significantly more effective than

vehicle in the treatment of moderate to moderatelysevere facial acne vulgaris.

The most common adverse reactions and side effects expe-rienced by patients applying clindamycin-benzoyl perox-ide gel is dry skin, occurring in approximately 12% ofpatients. Other local adverse events include applicationsite reaction (3%), pruritus (2%), peeling (2%), erythema(1%), and sunburn (1%). Adverse events that have beeninfrequently reported with the use of topical and systemicclindamycin include diarrhea, bloody diarrhea, and colitis(rarely including pseudomembranous colitis).

For therapeutic efficacy, the recommended regimen istwice daily applications. A convenient characteristic of thisgel is that it may be stored at room temperature up to 25°C(77°F) for 2 months following mixing. It is available in 25and 50 mg sizes.

Aditya K. Gupta, MDFrom the University of Toronto, Toronto, Ontario, Canada

N e w T h e r a p y U p d a t e

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Laser Surgery in Dark Skin