Healthy, Hydrated Skin and the Role of the Pharmacist

The skin is the body's largest organ. Nevertheless, the importance of its functional role is often underestimated, and its care is taken for granted. Establishing a skin care regimen is important to maintain healthy, hydrated skin, and incorporating preventive measures can help reduce or eliminate exacerbating conditions that may make unprotected skin more susceptible to dermatologic problems.

Pharmacists receive frequent requests for information about various skin care products available for cleansing, moisturizing, and photoprotecting the skin. As accessible health care professionals, pharmacists are in a key position to educate patients about appropriate skin care, especially the necessity of using moisturizers several times a day to improve the skin's appearance and texture and sustain its protective function. To understand the importance of moisturizing the skin and factors that may make the skin more susceptible to dryness, pharmacists must be familiar with the skin's physiology. Such knowledge allows pharmacists to make appropriate recommendations to patients about skin care products.

Physiology of the Skin

The structure and function of the stratum corneum (SC), which is the outermost layer of the epidermis, has a crucial protective role in maintaining optimal skin function. The SC affects the appearance and the overall health of the skin. Under optimal conditions, the SC minimizes water loss through the skin and assists in preventing irritants, germs, and allergens from entering the body.¹ This barrier function of the SC is the result of its unique structure and composition: the SC is composed of 2 components--the flat, keratinized corneocytes and the lipid-rich intercellular domains.² The intercellular domains primarily contain ceramides, sterols, and free fatty acids.^1,2 Corneocytes are the physical barrier of the SC and, when hydrated, enhance elasticity. The lipid layers of the SC operate as the moisture barrier.³ Any factors that damage the SC can also interfere with its barrier function and produce dryness of the skin, thus minimizing its protective role.¹ Under normal conditions, the SC's water content is approximately 10% to 30%. Thus this hydration enables the skin to maintain a supple, smooth, and flexible texture with elasticity.¹ Dry skin typically becomes apparent when water loss surpasses water replacement and the water content of the SC declines below 10%.¹

Classic symptoms of dry skin include roughness in texture and appearance, flaking, peeling, loss of flexibility or feeling of skin tightness, scaling, pruritis, and inflammation.^4,5 Dry skin is most prevalent on the legs and arms but can also occur elsewhere, such as in the facial area.

Risk Factors for Xerosis

Xerosis, commonly referred to as dryness of the skin, is a prevalent problem affecting more than 50% of older adults and it also is a prevalent cause of pruritis.⁴ Many factors contribute to xerosis. For example, with advancing age, the epidermis changes due to abnormal maturation or adhesion of the keratinocytes, and this results in a superficial, irregular layer of corneocytes.⁴ As an individual ages, the skin's hygroscopic substances decrease in quantity.⁴ Hormonal changes may also be a contributing factor among older individuals.^1,4

Why Is Moisturizing Important for Healthy Skin?

When the skin becomes dry, its ability to function optimally is compromised. Moisturization is a crucial element of basic skin care, particularly when the epidermal barrier changes and when the water content in the epidermis is reduced.³ The benefits of moisturizing the skin include repairing the skin barrier, increasing and retaining the water content, reducing transepidermal water loss, restoring lipid barriers, preserving the integrity and appearance of the skin, and attracting, holding, and redistributing water.^1,3

The Importance of Establishing Skin Care Regimens

The goals of therapy are to restore the hydration and barrier function of the skin. To that end, the patient should be educated in how to establish a routine cleansing and moisturizing regimen.⁴ A variety of strategies can be incorporated into a daily routine to prevent and treat dry skin. Selection of proper cleansers and moisturizers is essential to ensuring healthy skin; thus, pharmacists should evaluate the patient's medical and medication history and inquire about the patient's current skin care regimen, including types of cleansers and/or moisturizers used and the frequency of use. Referral to a dermatologist is recommended for patients with severe dry skin.

Cleansers

The main classes of cleansing agents include soaps, synthetic detergents (syndets), and lipid-free cleansing agents.¹⁰ Studies have shown that harsh surfactants in cleansers can damage the proteins and lipids of the skin, affecting its barrier function and causing irritation and pruritis, which in turn lead to drying of the skin.⁵ For this reason, mild agents with a slightly acidic or neutral pH, nonionic surfactants, and minimal skin residue are preferred cleansers.¹⁰ For example, mild cleansers may contain syndets such as sodium cocoyl isethionate, which is considered to be a mild yet effective detergent that will not cause skin irritation or interfere with the skin's proteins and lipids.^8,11

Moisturizers

A recent survey found that moisturizers are the third most commonly recommended nonprescription topical skin products.¹² Typically, moisturizers contain a combination of emollients (mainly lipids and oils), which promote barrier repair; occlusives (petroleum jelly), which create a hydrophobic barrier that seals in the body's natural moisture and blocks evaporation; and humectants (glycerin, urea, lactic acid).^1,12 Humectants enhance water absorption from the dermis into the epidermis and, in humid conditions, assist the SC in the absorption of water from the external environment.^1,12 Ideal moisturizers should hydrate the SC, be absorbed quickly, duplicate and augment the skin's natural moisture retention mechanisms, and provide immediate hydration to the skin. In addition, ideal moisturizers should be hypoallergenic, fragrance-free, and noncomedogenic to accommodate those with sensitive skin.³

The Role of the Pharmacist

When counseling patients, pharmacists should take the opportunity to increase awareness about the importance of a daily skin care regimen and explain the consequences of not taking care of the skin. If necessary, pharmacists should refer patients to a dermatologist. Pharmacists can be instrumental in identifying individuals who may be at a greater risk for developing dry skin, particularly those currently taking prescription medications or those with certain medical conditions. For example, approximately 33% of patients with diabetes have some type of dermatologic disorder that is the result of or affected by the diabetes.¹³ Through pharmacists' counseling, patients with diabetes can be reminded that, in addition to maintaining glycemic control, it is also imperative to adhere to a daily skin care regimen that includes mild cleansers and moisturizers to prevent further complications associated with dry skin.⁵ As health care professionals, pharmacists can provide expertise, knowledge, and advice to patients about skin care products and the health benefits of healthy, hydrated skin.

References

1. Dry Skin. PDR Health Web site. Available at: www.pdrhealth.com/patient_education/BHG01DE34.shtml.

2. Pilgram GS, Engelsma-van Pelt AM, Oostergetel GT, Koerten HK, Bouwstra JA. Study on the lipid organization of the stratum corneum lipid models by (cryo)-electron diffraction. J Lipid Res. 1998;39:1669-1676.

3. Kraft JN, Lynde CW. Moisturizers: What They Are and a Practical Approach to Product Selection. Skin Therapy Letter. 2005;10(5):1-8. Available at: www.medscape.com/viewarticle/505759.

4. Scott SA, Martin RW. Atopic dermatitis and dry skin. In: Berardi RR, Kroon LA, McDermott JH, et al, eds. Handbook of Nonprescription Drugs. 15th ed. Washington, DC: American Pharmacists Association; 2006:711-728.

5. National Institute of Diabetes and Digestive and Kidney Diseases. Prevent diabetes problems: keep your feet and skin healthy. Available at: http://diabetes.niddk.nih.gov/dm/pubs/complications_feet. 6. Xerosis. In: Chapter 56-Dermatological Diseases and Disorders. Available at: www.americangeriatrics.org/directory/ABIM/GRS/Derm.htm. 7. Dry Skin. Mayo Clinic Web site. Available at: www.mayoclinic.com/health/dry-skin/DS00560.

8. Ananthapadmanabhan KP, Moore DJ, Subramanyan K, Misra M, Meyer F. Cleansing without compromise: the impact of cleansers on the skin barrier and the technology of mild cleansing. Dermatol Ther. 2004;17(suppl 1):16-25.

9. Beers MH, ed. The Merck Manual of Health and Aging. Merck Research Laboratories. 2004; 432-433.

10. Bilowski J. The use of cleansers as therapeutic concomitants in various dermatologic disorders. Cutis. 2001;68:12-18.

11. Dove Soap Web site. Available at: www.dove.com. 12. American Osteopathic College of Dermatology. Dermatologic Disease Database: Xerosis. Available at: www.aocd.org/skin/dermatologic_diseases/dry_skin.html. 13. Skin Care. American Diabetes Association Web site. Available at: http://diabetes.org/type-1-diabetes/well-being/skin-care.jsp.