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www.skinandaging.comAugust 2009

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Acne in Ethnic Skin: Considerationsfor Positive Treatment Outcomes

Drug-Induced Acne and AcneiformEruptions: A Review

Tetracyclines in Acne and Rosacea

Pharmacotherapy Update: TheRole of Fixed-Dose CombinationTopical Therapy in the Treatment ofAcne Vulgaris

12th Annual Acne & Rosacea Issue

Acne and Rosacea ReviewHighlights of New Research and Treatment Trends

Experts estimate that the majority ofthe U.S. population in the 21st cen-tury will have skin of color.1 This,

combined with the reality that acne isbelieved to be the most prevalent skincondition in all Fitzpatrick skin types,2

(Table I) makes it critical to understandthe cutaneous histological variances thatexist in patients of color with acne.

BEYOND SKIN COLORTo best serve one’s patients, it is im-

portant to understand acne in ethnicskin. A patient’s heredity should beconsidered when developing a treat-ment plan for any skin condition. It isclear that color is only one of the im-

portant differences in the range of skinhues. By defining the key predisposi-tions of ethnic skin, we can identify thecomplex and unique needs of each pa-tient’s skin and, thereby, create success-ful treatment pathways.

Acne therapy can be particularly dif-ficult in darkly pigmented individuals, asthe acne lesions themselves and the ag-gressive products often used to treatbreakouts frequently result in post-in-flammatory hyperpigmentation. Usinggentle and effective exfoliation methodsas well as products to control sebum, in-flammation and bacteria will contributeto faster, more consistent results whileminimizing potential side effects.

EPIDERMAL AND DERMAL VARIANCES BETWEEN ETHNICITIES

The physiological differences betweenracial groups, though small, make a sig-nificant difference in determining one’spropensity toward specific skin condi-tions. The variability in skin thickness,barrier function, sebaceous and eccrinegland activity, and the melanogenesis andinflammatory response can significantlyaffect treatment outcome.

Epidermal variations include differ-ences in the stratum corneum (SC).One study showed that the African-American SC contains approximately22 layers, while that of Caucasian skinhas only 17.3 The epidermal thickness,

28 AUGUST 2009 SKIN & AGING

ACNE IN ETHNIC SKIN: CONSIDERATIONS FOR POSITIVE TREATMENT OUTCOMESHere, Dr. Jennifer Linder reviews what doctors need to know to treat acne in ethnic skin.

JENNIFER LINDER, MD

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Using topical ingredients capable ofreducing bacteria, inflammation andthe production of melanin will dra-matically limit the length of treatmentwhen used independently or in con-cert with a short course of oral or top-ical antibiotics. There are severalnatural and synthetically producedtopical agents that perform multiplefunctions within the skin.

• Azelaic acid is used in the treatmentof many dermatological conditions,such as acne, rosacea and hyperpig-mentation. Studies demonstrate anti-bacterial and anti-inflammatoryproperties, keratolytic action and se-lective cytotoxic effects on epidermalmelanocytes.22-23 Research has indi-cated that follicular bacterial contentis reduced by up to 97% after threemonths of daily use.24 Azelaic acid isunique in that its bactericidal benefitsare not affected by bacterial resist-ance, and it has less topical irritantpotential than benzoyl peroxide(BPO).25 In addition, azelaic acid de-creases cellular oxidation, which mayexplain its anti-inflammatory capabil-ities.26The multifunctional activity ofthis topical ingredient makes it par-ticularly efficacious for treating acnein patients of color.

• Kojic acid’s antibacterial and cop-per-chelating capabilities make itan excellent choice for ethnic skinwith acne. This fungi-derived in-gredient is typically used in pig-ment control formulations.27,28 Itsantimicrobial properties make iteffective in the clearing of currentacne lesions and preventing theformation of PIH.29 There is a po-tential for contact dermatitis fol-lowing kojic acid application;therefore, highly sensitive patientsshould be patch-tested to ensureno undue inflammation is causedduring treatment.30

• Lactic acid is a hydrophilic alphahydroxy acid (AHA) that reducescomedo formation by inducingdesquamation within the skinwhile also reducing bacterial colo-nization and inhibiting the forma-tion of tyrosinase during themelanogenesis process.31,32 Lowerconcentrations up to 5% are rec-ommended for daily use to pro-mote microscopic exfoliation ofthe corneocytes without causingsensitization or visible flaking33.Lactic acid also assists in increasingthe water content of the epidermis,due to its humectant properties.34

• Glycyrrhiza glabra (licorice) rootextract is a botanically derived top-ical agent that provides anti-inflam-matory benefits similar to a mildcortisone35 and inhibits lipase, anenzyme produced by the acne bac-teria that causes local irritation36.Licorice is also an effective tyrosi-nase inhibitor, making it incrediblyhelpful in the clearance and preven-tion of acne-induced PIH.37

• Retinoids include all members of thevitamin A family, including retinoicacid and its analogues (eg, retinol, ada-palene, tazarotene, etc.). Retinoids areamong the most important ingredientsin the management of acne, as they arecapable of normalizing follicular kera-tinization, reducing SC thickness andinflammation.38 Additionally, retinoidsassist in the reduction and hindrance ofhyperpigmentation by inhibiting ty-rosinase, enhancing cell turnoverand limiting melanosomal phagocyto-sis.39-41 While most retinoids are bene-ficial, I often prefer retinol over retinoicacid for ethnic skin types because of theirritant potential of pure retinoic acid.42

Retinol is successfully converted toretinoic acid within the skin, with anapproximate 10-fold conversion ratio(eg, 1% retinol is converted to 0.1%retinoic acid).43 The use of retinolmakes it possible to achieve similar re-sults to retinoic acid without a height-ened irritant risk.

• Salicylic acid is used in 0.5% to 2.5%concentrations for at-home acnetherapies. Its lipophilic moleculegives it the ability to penetratethrough sebaceous plugs and nor-malize the excess shedding of cellswithin the follicles.44 Topical irrita-tion is minimal with salicylic acid,perhaps as a result of its strong anti-inflammatory properties, making itideal for darker skin types45.

• Traditional acne therapeutics such asBPO can and have been used success-fully in the treatment of acne in darkercomplexions. The irritation potentialof BPO,24,46 however, makes it wise toconsider beginning with alternativeingredient options when workingwith more sensitive ethnic patients.


A C N E I N E T H N I C S K I N

Figure 1. Before (left) and After (right) 12 weeks of using these products: lactic acid-based facial cleanser; 2% hydroquinone,kojic acid and azelaic acid spot treatment; 0.5% retinol serum; arbutin and birch anti-inflammatory cream; broad-spectrum SPF30 daytime moisturizer; and aloe vera-based, anti-inflammatory evening hydrator. (No professional treatments were adminis-tered.) Photos courtesy PCA SKIN.

AUGUST 2009 SKIN & AGING 31

THE IMPORTANCE OF COMBINATION THERAPYCombination therapy is also ex-

tremely beneficial in the treatment ofacne in skin of color. Exfoliating chem-ical peeling treatments should be imple-mented in conjunction with daily careproducts to prevent corneocyte adhe-sion and to rid the skin of excess sebumand bacteria. By reducing SC im-paction, the application of peels willalso aid in the absorption of other acnecontrol products.

Chemical peels typically are eitherstraight acids in alcohol delivery ve-hicles or blends of several peelingagents. Peeling solutions that containhigher percentages of a single acid,such as glycolic acid, are more likelyto cause inflammation and potentiallypost-inflammatory hyperpigmenta-tion.47 I always recommend beginningthe treatment plan cautiously andgradually increase the activity level ofthe treatment regimen to prevent po-tential complications. Look for com-binations of lower percentages ofmultiple acids rather than a high per-centage of one peeling ingredient. Al-though more scientific data may beneeded, it has been demonstrated thatby blending several peeling agentswith anti-inflammatory, antioxidantand melanogenesis inhibiting ingredi-ents, the clinician is able to treat thepresent condition without producingside effects. To minimize complica-tions, it is also wise to limit the depthand aggressiveness of in-office proce-dures. Although some patients withdark skin may seem quite resilient, itis not about how much discomfort apatient can tolerate. Keeping dark skincalm during treatment is critical to apositive outcome.

AHAs are a group of organic car-boxylic acids that dissolve intercorneo-cyte bonds and encouragedesquamation. Each AHA has its ownancillary benefits, and while there areseveral available, the most common fortopical use are lactic and glycolic acids.Lactic and glycolic acids have been uti-lized for their topical benefits since thelate 1970s.48 Glycolic acid acts as astrong degreasing agent and assists with

the over-production of sebum but canbe dehydrating to those with a com-promised barrier function and drierskin types.49 Glycolic acid has thesmallest molecular size of all AHA, andits small size leads to quick penetrationand epidermolysis.50 This fast penetra-tion often induces higher instances ofinflammation and stimulation than isassociated with other AHA. Lactic acidis typically sourced from sour milk andsugars and is found naturally in humanskin. In addition to its exfoliation prop-erties, lactic acid also reduces bacteria,31

hydrates the skin34 and fights hyperpig-mentation by suppressing the forma-tion of tyrosinase.32 Due to its slightlylarger molecule, the amount of inflam-mation and stimulation associated withlactic acid penetration is relativelysmall,50 making it an ideal option forpatients with darker skin tones.

Trichloroacetic acid (TCA) is an ex-cellent peeling agent that has beensafely used for more than 80 years.50

TCA does not absorb into the blood-stream and works well for ethnic skinwhen used at lower percentages.51 Athigher percentages, one must be muchmore cautious, and pretreatment withmelanogenesis inhibitors is impera-tive.52 I recommend a series of treat-ments with blended acid TCAsolutions in concentrations up to 10%

for patients of color. There is no down-time associated with these types oftreatments. When used in conjunctionwith lactic acid and antibacterial, anti-inflammatory and anti-dyschromia in-gredients, this amount of TCA in apeel offers exfoliation benefits withoutthe risk of over-treatment.

Salicylic acid is a potent anti-acneagent that has been used in the topicaltreatment of acne since the 1950s.43

This peeling agent also possessesstrong anti-inflammatory propertiesthat reduce the chances of developingPIH following treatment.53,54 In onestudy performed on 35 Koreanwomen, 30% salicylic acid peels wereeffective in the clearing of inflamma-tory and non-inflammatory acne le-sions, and no instances of PIH werereported.55 Concentrations of 14% to20% are also very beneficial with acnepatients and are less uncomfortableduring treatment.53

CONCLUSION Every patient is different. A pa-

tient’s skin color, condition andpropensity toward inflammation andheightened melanogenic status shouldall be considered when developingany treatment plan. The treatment ofacne in ethnic skin types requires theutilization of multi-faceted topical in-

Figure 2. Before (left) and After (right) 12 weeks in which patient received four 20% salicylic acid mask treatments, and usedthese products: 2% salicylic acid cleanser; 2% salicylic acid and 5% azelaic acid spot treatment; 0.5% retinol serum; broad-spec-trum SPF 25 daytime moisturizer; botanical (marigold and cucumber), antibacterial evening hydrator. Photos courtesy PCA Skin.

AUGUST 2009 SKIN & AGING 29

however, is similar, suggesting that darkskin may be more compact and proneto cohesion. The presence of a moreimpacted SC may increase the occur-rence and severity of breakouts bytrapping sebum and other impuritieswithin the follicle. In addition,transepidermal water loss (TEWL) dueto impaired barrier function tends tobe greater in African-American, His-panic and Asian skin.1,4,5 This excessiveloss of moisture leads to barrier disrup-tion and may result in reduced protec-tion of the nerve endings.6 This mayexplain the heightened sensitivity totopical stimulation that is common inhigher Fitzpatrick types.7

Dermal differences include a thickerand more compact dermis in skin ofcolor3 and possible distinctions in bloodvessels and sebaceous and eccrine glands.Superficial blood vessels are more promi-nent and dilated in darker skin, althoughthey are typically more visibly apparent inlight skin.8 The prominence and dilationof superficial blood vessels in darker com-plexions may play a role in the inflamma-tion associated with acne in darklypigmented individuals. Some studies sug-gest that the sebaceous activity in African-American skin is higher than in Caucasianskin due to larger oil glands.9-11 It shouldbe mentioned that many industry expertsconsider these trials as flawed and believemore data is needed before determiningwhether the sebaceous variances betweenskin tones is significant. Regardless of skincolor, over-production of sebum con-tributes to the formation of acne lesions.Research on eccrine gland activity sug-gests that it is higher in African Americans

and Hispanics when compared to Cau-casians.1,11 This natural increase in sweatproduction may also be a contributingfactor to the inflammatory nature of acnein ethnic skin, as perspiration has beenshown to create local irritation.12

Perhaps the most obvious cutaneousdifference between ethnicities is skincolor. Although patients of all skin toneshave the same number of melanocytes,their function and the quality and dis-tribution of melanosomes are differentin ethnic versus Caucasian skin.13 Themelanogenesis process that leads to thedeposition of melanosomes over thenuclei of keratinocytes is identical be-tween races. In skin of color however,the melanosomes are filled with largermelanin granules, which are distributedmore evenly throughout the epider-mis.3,11 The melanocytes themselves aremore active and prone to excess and ab-normal pigment production.14 Thefunction and reactivity of melanocytesin darker skin make appropriate treat-ment selection crucial to avoiding com-plications and achieving desired results.

ACNE IN ETHNIC SKIN TYPESResearch indicates that acne is among

the top three skin concerns in AfricanAmericans and those of Latino and Asianbackgrounds.1 Although patients of colorare not necessarily more prone to acnethan fair-skinned individuals, the residualeffects are often much more severe indarker skin. Acne lesions in all ethnicitiesare a result of reduced desquamation,corneocyte cohesion and the resultantblocked pores, increased sebum produc-tion and bacterial proliferation. The type

of lesions seen in various heredities, how-ever, may differ. Grade IV, cystic andnodular acne is more prominent amongCaucasians and Latinos than in AfricanAmericans.15 Although the higher gradesof acne typically display higher amountsof inflammation than lower grades,comedonal acne in African Americanskin is much more inflamed than come-donal acne seen in Caucasian skin.16

Asian and Indian populations seem to bemore prone to papular lesions, thoughthe type of acne and severity will varydepending upon exact origin.17,18 All ofthese details are important to take intoconsideration when creating treatmentplans for patients of color.

EFFECTIVE INGREDIENT CHOICES FOR HIGHERFITZPATRICK SKIN TYPES

The key when treating ethnic skin withany skin condition is to limit inflamma-tion. Studies show that melanocytes inhigher Fitzpatricks display exaggerated re-sponses to cutaneous inflammation,which explains their propensity towardPIH. In addition, darker skin types havealso been shown to release moreprostaglandin inflammatory mediatorspost-trauma, than their lighter counter-parts.19 Pre-treatment with melanogenesisinhibitors, such as hydroquinone, kojicacid and arbutin for several weeks priorto a peel or procedure will assist in theprevention of these potential complica-tions.20 Hydroquinone is potentially irri-tating at higher percentages.21 Thisirritation could lead to PIH; therefore, Iprefer 2% concentrations blended withother, gentler melanogenesis inhibitors foradditional benefits without irritation.

Table.

FitzpatrickSkin Type Skin Color Visual Reaction to Sun Typical Sensitivity to

Chemical Peels Common Response to UV Rays

I Pale White Always Burns, Never Tans Very Resilient Skin Cancer & Hypopigmentation

II White Usually Burns Resilient Skin Cancer & Telangiectasia

III Light Brown, (Natu-rally Tan) Skin

Mildly Burns, Tans Relatively Well Moderately Responsive Telangiectasia

IV Moderate Brown Rarely Burns, Tans Well Sensitive Hyperpigmentation

V Dark Brown Very Rarely Burns, Tans Easily Moderately Sensitive Hyperpigmentation

VI BlackLeast Likely to Burn, TansVery Darkly

Very Sensitive Hyperpigmentation

gredients that are capable of address-ing several concerns simultaneously.Comprehensive gentle yet highly ef-fective treatment processes should in-clude daily application ofrecommended topicals and bi-monthly superficial chemical peels tosafely speed patient response and theeffectiveness of their treatment.�

Dr. Linder, a board-certified dermatolo-gist and fellowship-trained Mohs skin can-cer surgeon,is a volunteer Clinical Instructorin the Department of Dermatology at theUniversity of California, San Francisco. Dr.Linder is currently in private practice inScottsdale, AZ.

Disclosure:Dr. Linder is Chief Scientific Officer,PCA SKIN, is National Instructor, Dermik Aes-thetics (Sculptra), and National Instructor, Aller-gan Facial Aesthetics.

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Edition. Philadelphia: Lippincott Williams &Wilkins, 2006:203-256.34. Leyden JJ, Rawlings AV. Skin Moisturization.New York: Marcel Dekker, Inc., 2002:323-352.35. Baumann L. Cosmeceutical Critique:Licorice, Part 1 Skin & Allergy News 2007; 3:2436. Won S, Kim S, et al. Licochalcone A: A lipaseinhibitor from the roots of glycyrrhiza uralensis.Food Res. Intern. 2007;40(8):1046-1050. 37. Baumann L, Rodriguez D, et al. Natural con-siderations for skin of color. Cutis. 2006;78: 2-19.38. Rolewski SL. Clinical Review: Topicalretinoids. Dermatol Nurs. 2003;15:447-465.39. Draelos ZD, Retinoids in Cosmetics CosmeticDermatology 2005;18(1 suppl):3-540. Lotti T, Theirs, BH, et al. Dermatologic Clinics:Pigmentary Disorders. Philadelphia: Elsevier Saun-ders, 2007:357-358.41. Rendon MI, Gaviria JI. Review of skin-light-ening agents. Dermatol Surg. 2005;31(7):886-889.42. Kang S, Duell EA, et al. Application of retinol tohuman skin in vivo induces epidermal hyperplasia andcellular retinoid binding proteins characteristic ofretinoic acid but without measurable retinoic acid lev-els or irritation. J Invest Dermatol. 1995,105:549-556.43. Kang S. Mechanism of action of retinol. Cos-metic Dermatology. 2005;18(1 suppl):6-8.44. Del Rosso JQ. The many roles of topical sali-cylic Acid. Skin & Aging. 2005;12(4):38-42.45. Longshore SJ, Hollandsworth K. Acne vul-garis: One treatment does not fit all. Cleve Clin JMed. 2003;70:670-680.46. Leyden JJ. A Review of the Use of Combina-tion Therapies for the Treatment of Acne VulgarisJournal of the American Academy of Dermatology2003;49(3 suppl):200-21047. Roberts WE. Chemical peeling in ethnic/darkerskin. Dermatol Ther. 2004;17:196-205.48. Brody HJ, Monheit GD. A history of chemicalpeeling. Dermatol Surg. 2000;26(5):405-409.49. Effendy I, Kwangsukstith C. Functional changesin human stratum corneum induced by topical gly-colic acid: comparison with all-trans retinoic acid.Acta Derm Venereol. 1995;75(6):455-458. 50. Brody HJ. Chemical Peeling and Resurfacing.Second Edition. St. Louis: Mosby-Year Book,Inc., 1992:73-108.51. Collins PS. Trichloroacetic Acid Peels Revis-ited. J Dermatol Surg Oncol. 1989;15(9):933-940.52. Rubin MG. Manual of Chemical Peels Superfi-cial and Medium Depth. Philadelphia: LippincottWilliams & Wilkins, 1995:130-153.53. Baumann L. Cosmeceutical critique: salicylicacid. Skin & Allergy News. 2001;32(9):33.54. Guttman C. Choice of peeling agent dependson patient characteristics. Cosmetic Surgery Times.2003;6(2):18.55. Lee HS, Kim IH. Salicylic Acid Peels for theTreatment of Acne Vulgaris in Asian Patients Der-matol Surg. 2003;29(12):1196-1199.


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