Although skin types are usually classified as dry, normal, oily, or combination, dry skin is not necessarily a static condition. Dehydration is a condition that may affect all of these skin types. Skin care professionals must consider several different factors every time they address a client's dry skin, determine immediate treatment, and advise long-term homecare.

They need to understand what is going on beneath the surface and then select the appropriate treatment, products, and ingredients based on a thorough skin analysis that includes the client's history. They then need to take advantage of their captive audience by educating clients about the causes and remedies for dry skin and dehydration. In this way, the professional can maximize and prolong the benefits of the treatment while showing the client how to manage and even prevent the condition in-between visits.

SETTING THE SCENE
The stratum corneum is often compared to a brick and mortar wall that protects against the outside world. For normal skin types, this wall is a hydrolipid film that consists of a matrix of moisturizing factors and naturally produced lipids that keep skin hydrated and protected from the external environment. The key to healthy skin is its capacity to attract and retain moisture. Corneocytes, which are the bricks, are protective skin cells that contain proteins and natural moisturizing factors, which pull in moisture. Lipids, which represent the mortar, are composed of ceramides; fatty acids; and cholesterol, which are natural oils surrounding the corneocytes that regulate skin permeability, lock in moisture, and keep skin supple.

Dry skin occurs when the building blocks of its surface matrix are damaged or missing and left unrepaired. The outer layer of protection is compromised, like a brick and mortar wall that becomes damaged and steadily breaks down. Mature skin tends to suffer from dryness because, with age, the body slows down its natural production of oils. Aging, genetics, disease, and various stressors can cause the disruption of skin's natural moisturizing factors and lipid levels. The result is a damaged protective barrier that triggers a state of dehydration or transepidermal water loss.

Oily skin can be caused by overactive sebaceous glands that produce excess lipids, which is often due to genetics, hormonal changes, products that strip skin of natural oils, excessive use of product, seasonal changes, medications, or stress. Oily skin is prone to acne, but care should be taken not to over-cleanse or over-exfoliate the skin as these actions can strip it of protective oils, causing dehydration. It may seem counter-intuitive, but dehydrated skin can lead to an excess of oil to compensate for the lack of moisture, which is why dehydrated skin can sometimes be misinterpreted as oily skin.

Whether it is a matter of dry or oily skin, any damaged and malfunctioning protective barrier prevents skin from retaining a normal moisture level, even if water is present. For reference, think of what happens when water is poured into a paper cup punctured with holes. Correcting and repairing this issue has two phases: First, relieve the dryness with water-loving, water-binding molecules; second, protect the skin from further dryness with occlusive products that will keep the water inside and protect the skin from the outside.

However, if this broken surface is not repaired, skin loses elasticity and displays flaking, redness, cracking, wrinkles, and other signs of aging. At a deeper level, the healthy development of corneocytes becomes compromised, perpetuating further damage in a vicious cycle of dry, itchy, and irritated skin.

WHAT DRY SKIN DESPERATELY NEEDS
Water is absolutely essential to maintaining life and health and skin is especially demanding. Given that healthy, moisturized skin contains 60 to 70 percent water and two to 10 percent lipids, the key to repairing the skin's broken surface and restoring its protective barrier is to replenish moisture and lipids in the building blocks of the skin. This water-lipid balance is essential to maintaining the skin's texture, elasticity, and overall health.

When faced with dryness and dehydration, it is easy to react by using an abundance of occlusive oils or heavy creams. However, layering more waxes and oils on the skin prevents outside moisture from getting in and perpetuates the cycle of dehydration. It is important to start at the source; moisture needs to be added first and, afterward, occlusive products will help to seal in
that moisture.

Treatments for dry and dehydrated skin should include products that will deliver moisture and help skin retain moisture and maintain a healthy water-lipid balance. The first order of business in the facial room should a skin analysis, with a problem-solution approach to determining the specific cause of dryness and dehydration and how to treat it.

DRY SKIN SOLUTIONS
Exfoliation is an essential step in helping healthy skin cells to develop. Be careful not to over-exfoliate dry skin, which can cause the skin to overcompensate in response by triggering excess oil production. Alpha hydroxy acids, such as mandelic acid, should be gentle enough to clear away debris and smooth out rough texture so that moisturizing ingredients may be absorbed. Avoid the use of harsh peels and clay masks that draw moisture out of the skin.

After exfoliation, it is important to immediately replenish lost moisture and pave the way for healing. Look for skin care products that feature a combination of humectants, emollients, and occlusives, which work together to hydrate the skin, lock in moisture, and heal the protective barrier.

Humectants enhance the natural moisturizing factor's production by attracting and retaining water, thus improving the hydration of the stratum corneum.
Emollients, which include light oils, smooth out flakiness and help restore lipid levels, accelerating barrier repair. They may also have occlusive properties that prevent water from evaporating.

Occlusives, which include oils, butters, waxes, and silicones, take the place of the damaged protective lipid layer and create a protective barrier that locks in moisture. Botanical oils and butters are increasingly popular in skin care products as they prevent water loss, reduce redness, and absorb into the skin quickly.

Choosing the appropriate type of moisturizer is also essential. Since moisturized skin depends on a combination of water and lipids (such as oils, waxes, and butters) use products that not only seal in the natural moisture factor, but are also age-appropriate.

Gel-based creams are best for hydrating younger, normal-to-dry skin that is suffering from dryness and dehydration due to seasonal changes or environmental conditions, such as cold, dry, thin air at high altitudes.

Mature skin benefits from butter- and oil-based moisturizers and balms. The larger the molecule, the more outside protection it gives the skin. Oils and butters sit on top of the skin and protect it from chafing and extreme dryness, with minimal chance of skin irritation.

Mature skin will revive and blossom when sleep masks are used overnight. Their rich texture is ideal for dryness and photodamage and the skin will be hydrated and dewy the next morning.

Acneic skin may be dry and dehydrated, but choose a light moisturizer instead of applying heavy oils. Rich products may upset the lipid balance, clog pores, and prevent moisture from getting in, which only aggravates the signs of dehydration.

INGREDIENTS FOR DRY SKIN
Review ingredient lists at the spa and encourage clients to do the same for their products at home. Labeled ingredients are listed in descending order by weight, so think twice before choosing a product that has water listed as one of its primary ingredients since the presence of water in a formula does not necessarily equate to moisturized skin. When it comes to treating and healing dry skin, remember the moisture trinity: humectants, emollients, and occlusives.

Hydration-Boosting Superstars
Check the top of the ingredient list for hyaluronic acid, which is a potent humectant that absorbs moisture, expands it up to 1,000 times, and allows skin to retain that moisture. Look for this ingredient as the base of skin care products because it hydrates skin better than water, which can also dilute the product. Hyaluronic acid at a high molecular weight, such as 800 to 1,000 kiladaltons, provides extensive moisturization and elasticity. Studies have also shown that hyaluronic acid at a low molecular weight, such as 50 kiladaltons, penetrates the stratum corneum even more effectively.

Glycerin and urea are other popular hydrating agents that, like hyaluronic acid, are part of the natural moisturizing factor in the skin. When applied after exfoliation, they are well-absorbed and continue to provide hydrating benefits even after the product has been washed off.

For clients who prefer natural humectants, honey pulls and retains moisture from the air. The acidic and anti-irritant properties of honey help break down and clear away the flakiness of dry skin without causing skin sensitivity. Its vitamins and minerals, such as calcium, copper, magnesium, niacin, pantothenic acid, and thiamin, provide nourishment and replenishment to help heal and balance dry, dehydrated skin.

Sodium PCA and ceramides are emollients that are also powerful components of the skin's natural moisturizing factor and have strong moisture-binding properties. These popular humectants create a barrier that reduces the loss of moisture, preventing skin cells from drying out.

For clients who prefer botanicals, sacha inchi seed oil and butter are exotic yet very effective occlusive that contain up to 85 percent omega-3 and omega-6 essential fatty acids and deeply moisturize, repair, and maintain the barrier function. Cupuaçu seed butter contains vitamins A, B, and C, as well as mineral nutrients, such as calcium and selenium, that improve moisture retention and promote barrier repair. Abyssinian oil, evening primrose oil, moringa oil, baobab oil, baobab butter, and shea butter are also popular and effective and lack a heavy fragrance that might irritate sensitized skin.

Moisture-Busters
Salicylic acid and benzoyl peroxide are often successfully used to kill acne-causing bacteria, exfoliate the skin, and reduce the appearance of pores, but these ingredients can dehydrate and irritate dry skin, increase flakiness, and further damage the barrier function.

Retinoids are known as powerful wrinkle-smoothers, but they can cause irritation and dryness as a side effect. Therefore, ingredients like retinol, retinyl palmitate, tretinoin, isotretinoin, and other derivatives of vitamin A would be too harsh for dry skin.

Sodium lauryl sulfate and other lathering sulfates found in cleansers and toners can cause irritation. In place of products with these ingredients, professionals should try an oil-based or cream-based cleanser.

Avoid facial toners that contain isopropyl alcohol or denatured alcohol, which are used to enhance the absorption of other ingredients and provide a smooth finish. These alcohols can dry out and erode the skin's surface almost immediately. Cetyl, cetearyl, and stearyl alcohols are skin-friendly fatty alcohols that enhance texture and help keep other ingredients stable.

DRY SKIN PROBLEMS AND SOLUTIONS
Determining the specific cause of dryness or dehydration is paramount in treating clients effectively. Take the treatment a step further by talking to the client about the reasons underlying temporary or long-term symptoms of dry skin and give them suggestions about how to manage, treat, and prevent the condition in-between visits.

Problem: Seasonal changes with wind, cold air, and low humidity pull moisture away from the skin's surface and weaken the protective barrier. Solution: Apply moisturizers or serums more frequently and use a humidifier in the home.

Problem: Ultraviolet rays penetrate the skin, depleting the natural moisturizing factors and lipids. Solution: Use an SPF of at least 30 every day and reapply frequently. Avoid spending time outside in the middle of the day, when ultraviolet rays are the strongest, even on overcast days.

Problem: Lack of exfoliation causes a build-up of dead skin cells that prevents the skin from absorbing moisture. Solution: Use ultrasonic exfoliation tools or mild hydroxy acids, such as mandelic acid, two-to-three times per week.

Problem: Long and hot baths, showers, or soaks in hot tubs break down lipid barriers in the skin, leading to moisture loss. Solution: Take warm showers, limit the amount of time spent in the water, and apply moisturizer immediately after drying off.

Problem: The body's natural oil production diminishes with age. Prescription medications such as diuretics, retinoids, and antihistamines may dry out the skin. Low humidity, indoor heating, air conditioning, and recycled air in planes dry up moisture in the air and the skin. Harsh, irritating ingredients in skin care products or makeup dry out skin and break down lipids. Solution: Use products that include humectants, emollients, and occlusives to maintain the moisture-lipid balance of the stratum corneum.

Problem: Internal causes of dryness include physiological or medical conditions, such as diabetes, hyroid disease, eczema, and psoriasis. Solution: Advise the client to consult a board-certified dermatologist.

DEALING WITH DRYNESS
Everyone deals with dry skin when there is an imbalance in the water-lipid ratio of the stratum corneum and wherever there is not enough oil to create a barrier and lock in moisture. External causes, such as environmental factors and lifestyle choices, can lead to dry skin conditions with symptoms that may be temporary or long-term. Internal causes include age, genetics, and physiological or medical conditions.

For most clients, simple measures can be taken to treat, reduce, and prevent the symptoms of dryness and dehydration. Make sure exfoliants are used properly so they do not aggravate dryness by stripping the skin of essential lipids. Choose the appropriate moisturizer for the client's skin type and age, which will maintain the water-lipid balance of the skin's natural protective barrier. Teach clients how they can modify their skin care routine, lifestyle choices, and everyday behaviors in order to prolong the effects of their facial treatment and keep their skin looking healthy, even during seasonal changes. Encourage consistent, ongoing homecare so clients can transform their dryness and dehydration into a dewy, healthy-looking glow. As professionals treat, educate, and encourage their clients, their role as a skin care expert extends beyond the walls of the treatment room.

Janel Luu is founder and CEO of Le Mieux Cosmetics and PurErb Herbology-based Skincare & Aromatherapy. Luu has over 35 years of experience in the beauty industry as an educator, researcher, and formulator. She has taught over 37,000 skin care professionals and physicians on topics ranging from anti-aging cellular technology to centuries-old Meridian techniques.