1-s2.0-S0738081X01001997-main

8/13/2019 1-s2.0-S0738081X01001997-main

http://slidepdf.com/reader/full/1-s20-s0738081x01001997-main 1/6

Dry Skin and MoisturizersTIMOTHY CORCORAN FLYNN, MD

JAMES PETROS, BSROBERT E. CLARK, MD, PHDGREG E. VIEHMAN, MD

Almost every person will experience dry skinduring his or her lifetime.1 Many people expe-rience occasional episodes, but some have a

chronic problem with xerosis that is irritating and trou- blesome. In people with an atopic diathesis, dry skin canprogress to eczema. Moisturizers are the mainstay of treat-ment for dry skin, daily maintenance of normal skin, andadjunctive therapy for many skin diseases.2 This chap-

ter will discuss dryness of the skin and moisturization.

Dry Skin

The term dry skin describes an integument with a dry,rough, or scaly appearance with the possible presenceof reddening, cracking, or itching.3–5 The skin is lessflexible than normal, contributing to the irregular feel tothe touch. In people with darker skin types, the flaki-ness or increased scale shedding that is seen is some-times referred to as an “ashy skin.”6 In older individu-als, decreased desquamation of corneocytes andretention of keratin contribute to a rough or “dry” skin

appearance.7

Xerosis, xeroderma, asteatosis, and “winter itch”have all been used as synonyms for dry skin. Clinically,the skin initially appears to have an increase in skinmarkings,3 as the stratum corneum is less pliable andsmooth. Later, this dry skin can develop irregular ery-thematous lines. If pruritus develops, rubbing andscratching of the skin can lead to the clinical appearanceof either lichen simplex chronicus or eczema. The lowerlegs, dorsal forearms, and hands are often the first to beaffected with dry skin.

Environmental factors can play a role in dry skin.1

Anything that decreases the water content of the stra-tum corneum, such as cold or less humid climates, canaccentuate dry, “chapped” skin. Air-conditioning, coldweather, and exposure to wind are all said to worsenxerosis.

Dry skin most likely has a genetic component. Fa-miliar tendency toward dry skin has been documented.Siblings of patients are similarly affected. Dry skin can

be a life-long problem that can worsen with advancedyears. Diseases such as hypothyroidism or uremia cancause dry skin, as can therapy with certain medicationssuch as lithium or isotretinoin. People with chronicillness can also be troubled by xerosis.

Insults that remove the epidermal barrier of the skincan produce dry skin and irritation. Studies of cello-phane tape stripping of the stratum corneum have

shown an increase in transepidermal water loss(TEWL).8 Disturbance of barrier function of the stratumcorneum can cause dry skin as moisture is allowed toescape. Organic solvents and harsh detergents removelipid layers found within the stratum corneum anddecrease its barrier function.9

Treatment of dry skin is aimed at restoration of theepidermal water barrier. This is accomplished withmoisturizing agents that are topically applied to theskin. Excessive bathing or the use of hot baths or show-ers should be discouraged and the use of mild soapsrather than harsh soaps or detergents should be encour-

aged.6

Soap substitutes such as cetyl alcohol prepara-tions (Cetaphil) can be helpful in dry skin. Hydration of the stratum corneum by balneotherapy followed byeither addition of oil to the bath water or rapid appli-cation of emollients (occlusive agents) to the skin onexit from the bath can improve hydration of the stratumcorneum. Special moisturizing agents such as alpha- or beta-hydroxy acids can help promote corneocyte des-quamation and decrease roughness.10

Controllable environmental causes of dry skinshould be corrected. Humidification of the air is help-ful.6

Moisturizers

The use of moisturizers by mankind has historic roots.Ancient Egyptians frequently anointed their bodieswith oils. The Bible describes applications of oils to theskin, and Ancient Greek and Roman cultures regularlyapplied oil-containing products. Humans have recog-nized the value of externally applied lipids for thou-sands of years, and continue to value them.

Moisturizers are used today extensively by the pub-lic. Many consumers purchase or use over-the-countermoisturizers on a daily basis. The use of moisturizers is

From the Cary Skin Center, Cary, North Carolina, USA. Address correspondence to Timothy Corcoran Flynn, MD, Cary Skin

Center, P.O. Box 5129, Cary, NC 27512 USA.E-mail address: [email protected]

© 2001 by Elsevier Science Inc. All rights reserved. 0738-081X/01/$–see front matter655 Avenue of the Americas, New York, NY 10010 PIIS0738-081X(01)00199-7

8/13/2019 1-s2.0-S0738081X01001997-main


essential to treat simple xerosis and atopic dermatitis.

Quality moisturizers should be able to heal dry skinquickly, without causing irritation, and the patientshould feel the improvement immediately.11

What Are Moisturizers?

An excellent discussion of moisturizers has been pro-vided by Draelos,10 who notes that moisturizers areexternally applied compounds comprising multiplecomponents, including occlusive ingredients and hu-mectants.

Occlusive moisturizing ingredients are oily sub-stances (water-in-oil emulsions) that impair evapora-

tion of skin moisture by forming an epicutaneousgreasy film that impedes water loss. Petrolatum, a hy-drocarbon oil, is the most effective occlusive moistur-izer. Other hydrocarbon occlusive moisturizing ingre-dients include mineral oil, paraffin, and squalene.Vegetable fats such as cocoa butter, and animal fatssuch as lanolin are also occlusants. The fatty acids,lanolin acid, and stearic acid, as well as fatty alcoholssuch as lanolin alcohol and cetyl alcohol are additionalocclusive agents. Other general categories of occlusivesinclude polyhydric alcohols, wax esters, vegetablewaxes, phospholipids, sterols, and silicones.

Commercially, mineral oil is frequently used becauseit has a pleasant feel. However, it can only reduceTEWL by approximately 30%.10 Petrolatum is an excel-lent occlusive moisturizer and is blended with otheringredients to decrease its greasy feel. Lanolin, or woolalcohol, is not a commonly used occlusive moisturizingagent because of its expense, distinctive odor, and thepossibility of allergic contact dermatitis. Silicone is anewer occlusive agent. This product is noncomedo-genic, hypoallergenic, lacks a strong odor, and is fre-quently found in “oil-free” moisturizers. It has an oilyfeel but not a greasy sensation and is therefore oftenpreferred by patients.

Humectants are compounds that attract water fromthe dermis into the stratum corneum. These agents aredesigned to attract water up into the outer layers of theepidermis, as opposed to trapping water found in theenvironment (unless the relative ambient humidity ex-ceeds 70 to 80%).6,10 Moisturization of the stratum cor-neum occurs from below, with the dermis contributingmoisturization to the skin. Examples of humectantsinclude glycerin, propylene glycol, urea, sodium lac-tate, sorbitol, honey, and pyrrolidone carboxylic acid(PCA).

Moisturizers that contain only humectant elementswill draw water into the stratum corneum but notprevent the hydrated stratum corneum from losing itsincreased water content. As such, they can actuallyincrease TEWL.10 The use of only humectants in skinwith a defective barrier could actually contribute to adrying function of the outer layer of the skin. Thus,humectants are usually combined with occlusants.

What Do Moisturizers Do?

Moisturizers can immediately prevent excessive waterloss from the skin, principally via their occlusive ele-ments. The overall clinical effectiveness of moisturizersis short-lived as the topically applied material is quicklyshed along with the normally desquamating corneo-cytes. Tabata and colleagues12 have shown that thepersistent clinical effect of moisturizers may be attainedif the moisturizer is applied repeatedly on a daily basis.This finding may involve physiological alteration of thestratum corneum. The stratum corneum’s barrier func-tion prevents entry of foreign substances and the loss of internal substances, including water.13 The water con-tent of the stratum corneum should be greater than 10%for the skin to have a normal appearance and not feelrough, scaly, or dry. Ideally, the stratum corneumshould have a 20 to 35% water content.10 Moisturizers

Figure 2. Improvement in xerosis seen after a single applicationof a petroleum-based moisturizer.

Figure 1. Dry Skin on the lower leg of an 82-year-old woman.

388 FLYNN ET AL. Clinics in Dermatology Y 2001;19:387-392

8/13/2019 1-s2.0-S0738081X01001997-main


serve to return water content to the skin with the hu-mectants attracting water from the lower layers of theepidermis into the stratum corneum, and occlusive in-gredients preventing transepidermal water loss.

Moisturizers restore epidermal lipids, which play akey role in maintaining the permeability barrier of the

skin14

as well as increasing its plasticity.15

The excellentwork of Peter Elias and his colleagues demonstratedthat externally applied lipids do intercalate into theskin.16 Optimization of lipid components in topicalproducts increases uptake of these externally appliedsubstances into the inter-spaces of the corneocytes. Theoptimal lipid compounds mimic the naturally occurringcomponents of the lamellar bodies, which containsphingolipids, free sterols, and phospholipids.17

Moisturizers help heal a damaged epidermal barrier.Wounded skin attempts to heal itself by synthesizinglipids. The skin responds to a wound-induced increasein TEWL by upregulating epidermal lipid synthesis.10

Sterols and fatty acids are immediately synthesizedwith sphingolipids taking longer to be produced.18

Eventually, the skin is able to restore the lipid content tonormal levels. The studies of Loden and Anderson19

have shown that externally applied lipids in the form of canola oils and sterol-enriched fractions amelioratedsurfactant-induced irritation, demonstrating that lipidscan penetrate and heal damaged epidermis.

Experiments have shown that increasing TEWL by aslittle as 1% can simulate lipid synthesis.11 The use of amoisturizer or a semi-permeable dressing can help re-store barrier function. Completely occlusive dressings

that are impermeable to water do not initiate lipidsynthesis because their use reduces the TEWL to zero.10

Moisturizers can make skin feel smoother, a propertyknown as emolliation. Cracks and gaps between thedesquamating corneocytes are filled by the moisturizer,decreasing the rough quality of the skin. Moisturizersalso decrease friction on the skin, improving the lubric-ity. Substances with good emolliation properties in-clude alcohols and esters. Alcohols such as octyl dode-canol, hexyl dodecanol, or oleyl alcohol are excellentskin-smoothing agents and are not, as commonlythought, drying to the skin. Examples of esters that aregood emollients include oleyl, oleate or octyl stearate,PEG-7, glycerol, cocoate, myristyl myristate, isopropylmyristate, and stearyl isononanoate.10

All moisturizers contain lipids and, when applied,can make the skin feel greasy. The physical propertiesof the individual moisturizers contribute to this greasyfeeling. Greasier components such as petrolatum aremore difficult to spread and have increased occlusiveproperties. Greasy components include oleyl oleate andtriglycerides. Less greasy emollients include the com-monly used isopropyl calmetate, stearate, and myris-tate.10 Dibutyl Ditate is a less greasy emollient. Lotionformulations favor more easily spreading ingredients,

whereas thick, heavy moisturizers use heavier, less eas-ily spreading ingredients.

Formulation and Moisturizers

Most moisturizers are combination cosmetic products11

in which individual ingredients are combined to elicit

the desired effect. The aesthetic qualities of the mois-turizer are essential for patient and consumer accep-tance and compliance as well as for the individualtherapeutic design of the moisturizer. Consumers andpatients seem to prefer a less greasy product that isapplied smoothly.1 As Draelos has pointed out, manymoisturizers have an easily spreading, less viscousemollient in combination with a medium spreading,more viscous emollient.10 A sensation of early, easysmoothness to the skin occurs with thinner, easier-spreading agents, whereas the long-lasting efficacy of the moisturizer is maintained by the thicker compo-

nents that are more difficult to spread.

Additives to Moisturizers

New agents have been developed that are now in-cluded in moisturization products. These agents havedifferent functions than simply reducing TEWL or re-constituting the lipid components of the stratum cor-neum. Additives to moisturizers include the hydroxyacids, including the alpha- and beta-hydroxy acids,which are organic carboxylic acids having a hydroxylgroup at the alpha or beta position, respectively. Alpha-hydroxy acids have been shown to improve the appear-

ance of photodamaged skin.20

Glycolic acid increasescorneocyte desquamation.21 Alpha-hydroxy acids canpromote cell proliferation and increase collagen synthe-sis in cell culture.22

Salicylic acid is the only beta-hydroxy acid. Its pos-tulated mechanism of action centers on the dissolutionof the intercellular cement between adjacent corneo-cytes, reducing corneocyte adhesion.23 It is unique inthat it can enter the pilosebaceous unit and increaseexfoliation in the oily areas of the face. This, along withits safety profile, explains its frequent use in acne ther-apy and as an agent that, when added into a moistur-izer, can decrease the oil production by the sebaceousgland. Due to its exfoliating effects, salicylic acid is beneficial in aging skin due to increased desquamationof the stratum corneum. Increased desquamationmakes older skin feel smoother and “fresher.”

Urea can also be added to moisturizers and enhancesthe water-binding capacity of the stratum corneum bydisrupting hydrogen bonding.10 Urea exposes water- binding sites on corneocytes and promotes desquama-tion by decreasing the intercellular cementing sub-stance between the corneocytes.24 Also, long-termtreatment with urea has been demonstrated to decreaseTEWL.25 A possible explanation may involve urea-in-

Clinics in Dermatology Y 2001;19:387-392 DRY SKIN AND MOISTURIZERS 389

8/13/2019 1-s2.0-S0738081X01001997-main


duced reduction in epidermal cell proliferation which,in turn, increases the size of corneocytes. Larger corneo-cytes lower skin permeability, thereby lowering TEWL.It has also been shown that long-term urea applicationreduces the susceptibility of the skin to sodium laurylsulfate (SLS) irritation. A possible mechanism may be

urea-induced alteration of the binding capacity of thestratum corneum. This protective effect (after pro-longed application) has promising clinical ramificationsfor the use of urea-containing moisturizers to reducecontact dermatitis from irritant stimuli.

An attempt to mimic the natural water-holding ca-pacity of the dermis is made with the addition of so-dium PCA (2-pyrolidone-5-carboxylic acid), whichmimics glycosaminoglycans.10 This agent functions as ahumectant, drawing water from the dermis and lowerepidermis into the stratum corneum.26 This increasedwater content provides the stratum corneum with agreater degree of flexibility, better mechanical strength,

and a softer feel.Other items can be added to moisturizers that are

often sold as special cosmetic formulations. Natural andsynthetic vitamin A derivatives, known as retinoids, areoften added to moisturizers and touted to be antioxi-dants. They are extensively prescribed for antiagingpurposes, as they are capable of preventing and revers-ing the signs of sun damage.27 In nature, vitamin A(retinol) is capable of functioning as a free-radical scav-enger that protects plants from UV-induced free-radicaldamage. The vitamin A derivative retinoic acid is anactive chemical compound that restores the epidermis

to youthful appearance by increasing the thickness of the epidermis as well as promoting the deposition of new collagen within the dermis.27 Retinoic palmitate isan easily formulated retinoid that can be added tocosmetic creams. In its original form, retinoic palmitatedoes not have any biological activity in skin. Followingaromatic cleavage by the skin, retinol forms retinoicacid, the active form.28 The amount of retinoic acid thatis made available to the skin from retinol put into themoisturizers is small. Additionally, vitamin A, in highenough concentrations, can behave as a humectant,drawing water into the epidermis.

Vitamin C can be added to moisturizers that manycompanies claim are effective as antioxidants. Ascorbicacid can act as an antioxidant by scavenging free radi-cals, and vitamin C has sunscreen properties.29 VitaminC in cell culture studies produces increased collagenproduction.30 A 3-month randomized double-blind ve-hicle-controlled study of 19 patients demonstrated astatisctically significant improvement in wrinkles whenassessed using optical profilometry.31 In hairless mice,topical vitamin C decreased photoaging changes.32 It ispossible to get topically applied vitamin C to enter theskin but vitamin C must be formulated at a pH of 3.5and the maximal concentration for optimal absorption

is 20%. Proper formulation of vitamin C is essential toachieve penetration into the skin.33

Vitamin E can be added to moisturizers. Vitamin Eincludes tocopherols and tocotrienols, with the biolog-ically active forms consisting of only alpha and gammatocopherols. Vitamin E is the most important lipid-

soluble antioxidant naturally occurring in cell membranes.34 Orally, it is a free-radical scavenger but it doeslittle when topically applied to the skin. There is limiteddata as to the actual benefit of vitamin E being added tomoisturizers. Due to its antioxidant and light absorbingcapacities, it does function as a weak sunscreeningagent (mostly UVB), having a sun protection factor of approximately three when repeatedly applied to theskin.35,36 Vitamin E is an excellent antioxidant whenorally consumed but has limited effectiveness whenapplied to the skin. In the stable form of tocopherylacetate, vitamin E prevents oxidation of chemical com-ponents found within the bottle of the moisturizer. This

preservative function coupled with excellent skin con-ditioning effects is the main reason that vitamin E isfrequently added to moisturizers.10 Consumers seem tolike the idea of vitamins being added to moisturizingcomponents.

Panthenol can be added for it humectant properties.Added to moisturizers as well as hair care products, itcan hold and attract water. Panthenol increases theplasticity of hair, making hair feel softer and moremanageable. Also known as vitamin B5, panthenol isused for its physical properties of increasing plasticity,rather than for any pure vitamin activity it may have.

How Do Dermatologists Use Moisturizers?

Dermatologists use moisturizers for a variety of condi-tions. Most commonly, moisturizers are used to restore barrier function to the skin in cases of xerosis andeczema. Lipids applied externally to the skin can pen-etrate the epithelium and modify the normally synthe-sized lipids in the skin.37 Studies have shown that innormal skin a one-time application of moisturizer didnot cause a long-term benefit,38,39 but twice-daily appli-cation of a moisturizer for 1 week produced long-termchanges for at least 7 days after treatment.40 Lane andDrost41 studied the effect of a water-in-oil emollient onpremature neonatal skin and found less dermatitis as aresult of regular moisturization.

Moisturizers can also be used to decrease inflamma-tion in damaged and irritated skin. Loden and Anders-son19 have shown that moisturizers containing canolaoil and its sterol-enriched fraction can reduce irritationinduced by sodium lauryl sulfate, possibly by supply-ing the damaged barrier with adequate lipids.

Moisturizers can help prevent irritant contact derma-titis.25,42–46 A fascinating study by Hannukela and Kin-nunen42 showed moisturizer application to be helpful.


8/13/2019 1-s2.0-S0738081X01001997-main


Subjects washed their arms with a liquid dishwashingdetergent and applied a commercial moisturizer to onearm, using the other untreated arm as a control formoisturization. TEWL increased in the unmoisturizedarm, which developed a visible dermatitis. The use of moisturizers prevented the development of dermatitis

and significantly promoted the healing process. Thevalue of moisturizers in treating soap-induced xerosishas been nicely documented.45,46

Moisturizers can increase desquamation. Alpha-hy-droxy acids and beta-hydroxy acids added to moistur-ization products can increase corneocyte desquamation,producing a smoother and softer sensation to the epi-dermis. These hydroxy acids can also be useful in thetherapy of photoaged skin. Studies by Stiller and col-leagues47 have demonstrated at least one grade of im-provement (on a 9-point scale) in the assesment of overall photodamage and sallowness.

Proper knowledge of moisturizers and scientifically

based recommendations for their use can help patientswith sensitive skin syndrome. These patients are quitesensitive to externally applied products, especiallythose containing fragrances, and often report stingingor burning sensations when creams are applied to theskin. A knowledge of moisturizers, including sub-stances that might produce contact dermatitis or anirritant dermatitis, can help control sensitive skin. Pa-tient compliance can be increased if dermatologistshave a solid working knowledge of moisturizers andtake the time to explain the importance of moisturiza-tion to patients. Patients appreciate consulting with

their physician as to which moisturizer should be used.They appreciate a scientific explanation of appropriatetherapy.

It is important to remember that moisturizer formu-lations are not without problems. Patients who usemoisturizers regularly may be susceptible to contactdermatitis,48 often as a result of preservatives or fra-grances found within many commercial preparations.Many patients believe that they must use a hair or skinmoisturization product daily and some products canirritate the skin. Excessively greasy or oily products canexacerbate or initiate dermatoses such as acne or follic-ulitis, and almost every dermatologist has seen a pa-tient with seborrheic dermatitis who believes that theproblem is “dry skin.” Treating seborrheic dermatitiswith moisturizers can often exacerbate their problem.

References

1. Spencer TS. Dry skin and skin moisturizers. Clin Derma-tol 1988;6:24– 8.

2. Loden M. Biophysical properties of dry and normal skinwith special reference to effects of skin care products. ActaDerm Venereol (Stockh) 1995;Suppl 192:1–48.

3. Chernosky ME. Clinical aspects of dry skin. J Soc CosmetChem 1976;27:24–8.

4. Seitz JC, Rizer RL, Spencer TS. Photographic standardiza-tion of dry skin. J Soc Cosmet Chem 1984;35:423–37.

5. Kantor I, Ballinger WG, Savin RC. Severely dry skin:Clinical evaluation of a highly effective therapeutic lotion.Cutis 1982;30:410–24.

6. Lazar AP, Lazar P. Dry skin, water, and lubrication. Cos-metics Cosm Surg Dermatol 1991;9:45–51.

7. Tabata N, Tagami H, Klingman AM. A 24 hr occlusiveexposure to 1% SLS induces a unique histopathologicinflammatory response in the xerotic skin of atopic der-matitis patients. Acta Derm Venereol (Stockh) 1998;78:244–7.

8. van der Valk PG, Maibach HI A functional study of theskin barrier to evaporative water loss by means of re-peated cellophane tape stripping. Clin Exp Dermatol1990;15:180–2.

9. Grubauer G, Feingold KR, Harris RM, Elias PM. Lipidcontent and lipid type as determinants of the epidermalpermeability barrier. J Lipid Res 1989;30:89–96.

10. Draelos ZD. Therapeutic moisturizers. Dermatol Clin

2000;18:597–607.11. Jackson EM. Moisturizers: Adjunct therapy and advising

patients. Am J Contact Dermatitis 1996;7:247–50.12. Tabata N, O’Goshi K, Zhen YX, Klingman AM, Tagami H.

Biophysical assessment of persistent effects of moisturiz-ers after their daily applications: Evaluation of cor-neotherapy. Dermatology 2000;200:308–13.

13. Klingman AM. The biology of stratum corneum. In: Mon-tagna W, Lobitz WC, editors. The epidermis. Orlando:Academic Press, 1964, pp 387–433.

14. Elias PM. Lipids and the epidermal permeability barrier.Arch Derm Res 1981;270:95–117.

15. Jemec GBE, Wulf HC. Correlation between the greasiness

and the plasticizing effects of moisturizers. Acta DermVenereol (Stockh) 1999;79:115– 7.16. Zettersten EM, Ghadially R, Feingold KR, Crumrine D,

Elias PM. Optimal ratios of topical stratum corneum lip-ids improve barrier recovery in chronically aged skin.

J Am Acad Dermatol 1997;37:403– 8.17. Grubauer G, Elias PM, Feingold KR. Transepidermal wa-

ter loss: The signal for recovery of barrier structure andfunction. J Lipid Res 1989;30:323–33.

18. Hollenran WM, Feingold KR, Mao-Qiang M, et al. Regu-lation of epidermal sphingolipid synthesis by permeabil-ity barrier function. J Lipid Res 1991;32:1151–8.

19. Loden M, Andersson AC. Effects of topically appliedlipids on surfactant-irritated skin. Brit J Derm 1996;134:

215–20.20. Thibault PK, Wlodarczyk J, Wenck A. A double blind

randomized clinical trial on the effects of a daily glycolicacid formulation in the treatment of photodramaging.Dermatol Surg 1998;24:573–7.

21. Berardes E, Distante F, Uignol BP, et al. Alpha-hydroxyacids moderate stratum cornium barrier function. J Der-matol 1997;137:934–8.

22. Kim SJ, Won YH. The effect of glycolic acid on culturalhuman skin fibroblasts. Cell proliferative effect and in-creased collagen synthesis. J Dermatol 1998;25:85–9.

23. Draelos ZD. Hydroxy acids for the treatment of agingskin. J Geriatr Dermatol 1997;5:236–40.

Clinics in Dermatology Y 2001;19:387-392 DRY SKIN AND MOISTURIZERS 391

8/13/2019 1-s2.0-S0738081X01001997-main


24. Raab WP. Uses of urea in cosmetology. Cosmet Toilet1990;105:97–102.

25. Loden M. Urea-containing moisturizers influence barrierproperties of normal skin. Arch Dermatol Res 1996;288:103–7.

26. Wilkinson JB, Moore RJ. Harry’s cosmeticology, 7th ed.New York: Chemical Publishing, 1982, 62–64.

27. Kligman LH, Do CH, Kligman AM. Topical retinoic acidenhances the repair of ultra violet damaged dermal con-nective tissue. Connect Tissue Res 1984;12:139–50.

28. Duell EA, Derguini F, Kang S, et al. Extraction of humanepidermis treated with retinol yields retro-retinoids inaddition to free retinol and retinyl esters. J Invest Derma-tol 1996;107:178–82.

29. Pelle E, Muizzudin N, Mammone T, et al. Photoprotectionagainst endogenous and UVB-induced oxidative damagein stratum corneum lipids by an antioxidant-containingcosmetic formulation. Photodermatol Photoimunol Pho-tomed 1999;15:115–9.

30. Darr D, Dunston S, Faust H, Pinnell S. Effectiveness of antioxidants (vitamin C and E) with and without sun-screen as topical photoprotectants. Acta Dermatol Venerol1996;76:264–8.

31. Darr D, Combs S, Dunston S, et al. Topical vitamin Cprotects porcine skin from ultraviolet-induced erythema:A human study in vivo. Br J. Dermatol 1998;139:332–9.

32. Bisset DL, Chatterjee R, Hannon DP, Photoprotection ef-fect of superoxide–antioxidants against ultraviolet radia-tion -included chronic sun damage in the hairless mouse.Photoderm Photoimmunol Photomed 1990;7:56– 62.

33. Pinnell SR, Yang H, Omar M, et al. Topical l-ascorbic acid:Percutaneous absorption studies. Dermatol Surg 2001;27:137–142.

34. Burton GW, Joyce A, Ingold KU. Is vitamin E the only

lipid-soluble, chain-breaking antioxidant in human bloodplasma and erythrocyte membranes? Arch Biochem Bio-phys 1983;221:281–90.

35. Idson B. Vitamins and the skin. Cosmet Toilet 1993;108:79–92.

36. Mayer P, Pittermann W, Wallat S. The effects of vitamin Eon the skin. Cosmet Toilet 1993;108:99–109.

37. Wertz PW, Downing DT. Metabolism of topically applied

fatty acid methyl esters in BALB/C mouse epidermis. JDermatol Sci 1990;1:33–7.

38. Blichmann CW, Serup J, Winther A. Effects of singleapplication of a moisturizer: Evaporation of emulsionwater, skin surface temperature, electrical conductance,electrical capacitance, and skin surface (emulsion) lipids.Acta Derm Venereol (Stockh) 1989;69:327–30.

39. Loden M, Lindberg M. The influence of a single applica-tion of different moisturizers on the skin capacitance. ActaDermatol Venereol 1991;71:79–82.

40. Serup, J, Winhter, A, Blichmann, CW. Effects of repeatedapplication of a moisturizer. Acta Derm Venereol (Stockh)1989;69:457–9.

41. Lane AT, Drost SS. Effects of repeated application of emollient cream to premature neonates’ skin. Pediatrics1993;92:415–9.

42. Hannuksela A, Kinnunen T. Moisturizers prevent irritantdermatitis. Acta Dermatol Venereol 1992;72:42–4.

43. Halkier-Sorenson L, Thestrup-Pedersen K. The efficacy of a moisturizer (Locobase) among cleaners and kitchen as-sistants during everyday exposure to water and deter-gents. Contact Dermatitis 1993;29:266–71.

44. Gammal CE, Pagnoni A, Klingman AM, Gammal SE. Amodel to assess the efficacy of moisturizers—the quanti-fication of soap-induced xerosis by image analysis of ad-hesive-coated discs (D-Squames). Clin Exp Dermatol1996;21:338–43.

45. Olivarius FDF, Hansen AB, Karlsmark T, Wulf HC. Waterprotective effect of barrier creams and moisturizingcreams: A new in vivo test method. Contact Dermatitis1996;35:219–25.

46. Ramsing DW, Agner T. Preventive and therapeutic effectsof a moisturizer. An experimental study of human skin.Acta Derm Venereol (Stockh) 1997;77:335–7.

47. Stiller MJ, Bartolone J, Stern R, et al. Topical 8% glycolicacid and 8% L-lactic acid creams for the treatment of photodamaged skin. A double-blind vehicle-controlledclinical trial. Arch Dermatol 1996 Jun;132:631–6.

48. Held, E, Sveinsdottir, S, Agner, T. Effect of long-term useof moisturizer on skin hydration, barrier function, andsusceptibility to irritants. Acta Derm Venereol (Stockh)1999;79:49–51.


1-s2.0-S0738081X01001997-main

Documents

Transcript of 1-s2.0-S0738081X01001997-main