What is dehydrated skin?
Dry and Oily Dehydrated Skin Explained
Dear Dr. Bailey, What is the difference between dry and dehydrated? A lot of skin care lines carry different products for dry skin and so-called dehydrated skin. Can the skin be oily and dehydrated? Can skin be dry and not dehydrated? Or is dehydrated skin only a marketing buzzword? Thanks a lot for giving great answers to great questions on your blog! I really like reading your answers and skin care advice. :) and thanks a lot for this answer too. Judith
Hello Judith, yes, in the context you describe, this is a marketing term. It's an important question though because it's important to understand skin hydration and the role of moisturizers, oil and humectants in preventing skin dehydration.
Skin moisture (hydration) is actually about water content and not oil.
Water in skin contributes to its plumpness and suppleness. Hydrated skin is dewy and soft. The water content of your skin will ebb and flow quickly because your skin readily absorbs water from your bath, shower and humid air. Your skin will also lose water to dehydrated air, which is anything under 85% relative humidity!
What is hydrated your skin?
Hydrated skin has water held next to skin keratin. To understand this, know that the stratum corneum of your skin (the epidermis) is what we consider the skin's 'water proofing' layer. It is the top most layer of skin and it plays a key role in protecting your skin from water loss (called transepidermal water loss, or TEWL).
The stratum corneum has a 'brick and mortar' structure composed of:
- dead skin cells (called corneocytes) that are like 'bricks' filled with keratin protein, and
- lipid mortar that surrounds all the 'bricks' (comprising about 20% of the stratum corneum) to help prevent water loss.
It’s the keratin protein in the dead cells that absorbs water. When fully hydrated, these dead cells swell and soften by as much as 50% beyond their dry form. Fully hydrated keratin is plump and supple compared to keratin that is not fully hydrated.
You hydrate skin keratin to create plump, soft, supple, dewy skin using your skin care products and routine. - Dr. Cynthia Bailey
What is dehydrated skin?
Dehydrated skin contains inadequate water for skin to be supple, soft and healthy. In the extreme, dehydrated skin will become crepey, brittle, rough and ultimately become symptomatic, at risk for asteatotic/xerotic eczema and irritant dermatitis.
How do you trap water into the skin to prevent dehydration?
The skin lipids between dead cells of the stratum corneum are the first line of defense for TEWL (skin water loss). These lipids are composed of ceramides, cholesterols and other free fatty acids. You need enough of these skin lipids to prevent water loss. There are also other ways to trap water in the skin and you want to use as many as possible to prevent dehydrated skin.
Occlusive ingredients prevent skin dehydration
Occlusion in dermatology, is the application of something on the skin that prevents water loss. Oils (such as mineral oil) and petrolatum (Vaseline) have been used for many years. You can also use botanical oils for the same purpose. Dermatologists also use wraps and dressings to prevent TEWL. The Korean Skin Care slugging trend is really occlusive skin care using Vaseline. Facial hydrocolloid masks can do the same thing for a quick rehydration.
Moisturizers traditionally prevent dehydrated skin by utilizing an oil or oil-like ingredient such as petrolatum to occlude (trap) water and prevent evaporation on a daily basis. They are most effective when applied right after washing/wetting the skin where they can seal in the water that your skin just absorbed when it was wet. - Dr. Bailey
Humectant ingredients help bind water inside the skin
Ingredients that chemically bind water are called humectants. In skin care, these include the well-loved ingredients hyaluronic acid and glycerin. Sodium PCA is another effective humectant. It is part of your skin's natural moisturizing factor. Low concentration urea is another humectant you can find in skin care products. (Don't confuse this with high concentration urea which functions as an exfoliant.)
Dehydrated Skin Products
Skin with adequate trapped water is considered hydrated and you do that with the right products for your unique complexion.
The best oils for dehydrated skin
Oils for dehydrated skin don't have to be greasy
My Natural Lotion and Butter are also enriched with organic aloe vera and vegetable derived glycerin. My Omega Enriched Booster Oil is a blend of fast absorbing oils that never feel greasy.
Dehydrated oily skin
Oily skin will hold more moisture because it produces its own moisturizing oil.
Skin sebum is very efficient and wonderful as a natural skin moisturizer until the oily shine becomes annoying. Harsh soaps will remove the oil and it takes time to reproduce it so any absorbed water from washing may have evaporated by the time the oil begins to re-coat the skin. Applying oil-free humectants can help hold water to skin until skin sebum can coat the skin. It's also possible to use a light-textured moisturizer applied in a thin layer on top of humectants to hold water and prevent dehydrated oily skin.
Some of the best oil-free moisturizing ingredients to hydrate skin are:
- hyaluronic acid (sodium hyaluronate)
- Sodium PCA
My pharmaceutical-grade hyaluronic acid containing products including Green Tea Antioxidant Skin Therapy and/or Instantly Luminous Multi Action Serum. Instantly Luminous serum is built with an advanced formulation of fractionated hyaluronic acid to stratify water throughout the layers of the epidermis for maximal hydration. It works so well with the Green Tea Therapy that I created my popular Layered Up Besties Kit with them both!
I've used this combination of great products for a long time now and I love them. My skin is brighter and never feels dry. Lynn
Oil-free humectant rich products hold water in the skin without oil and represent that brilliant bridge between science and nature that I love so much!
Dehydrated face skin care products
Products with humectants, ceramides and squalane are top choices for hydrating all skin types including oily skin. Benefit from all of them when you top the humectants in Layered Up Besties with non-greasy lipid replenishing ceramides and squalane in Daily Face Cream. Dry complexions benefit from adding a few drops of my Omega Enriched Face Booster Oil to the Daily Face Cream. I do this during dry weather and my skin loves it!
Dehydrated oily skin can also happen if you suffer from certain common skin problems that lead to skin barrier weakness that increases skin water loss.
Dehydrated oily skin due to skin problems that weaken skin barrier include:
- Repeated contact with harsh soaps (for sensitive skin this can include products with the sodium laurel sulfate family of ingredients) or harsh chemicals (like rubbing alcohol or household cleaners).
Rashes such as facial dandruff (seborrhea) and rosacea that cause compromised skin barrier and water loss.
- Having a genetic tendency for eczema, asthma and allergies that means you may also have an inherently vulnerable skin barrier and are one of the classic 'sensitive skin' people.
- Exposure to harsh environments such as windy, cold climates, or simply going between cold outdoor temperatures and heated indoor environments which can irritate the skin and cause water loss.
it's possible to have oily skin that is also dehydrated!
Dehydrated leg, arm and body skin
Leg and body skin have fewer oil glands and are often characterized as dry, especially after the age of 55 when skin repair mechanisms really start to drop off. Arms and leg skin is especially prone to TEWL and thus dehydration. Dryness and dehydration here go together and lead to crepey, flakey, rough and chalky looking skin that just looks and feels old! I've spent my career helping people prevent this.
How to prevent dehydrated leg, arm and body skin
I've told patients for years that applying a good moisturizer to at least the arms and legs after every bath or shower is really important for keeping arm and leg skin healthy as we age. The best approach is to alternate a good body lotion or cream with a medical-grade glycolic acid skin care routine.
- The lotion or cream will replenish the skin lipids to help prevent TEWL.
- The glycolic acid will stimulate the skin to produce its own hyaluronic acid.
In my 35 years of dermatology experience, I've found that this is the only real way to visibly increase the hyaluronic acid content of arm and leg skin. The glycolic acid will also help remove skin flakes and soften skin roughness. The end results are soft, dewy and youthful arm and leg skin that resist age spots and the crustiness associated with aging.
Yep, none of us has to resign our self to crusty old skin. We can alternate a good moisturizer with a medical-grade AHA routine on our arm, leg and body skin and maintain dewy youthful skin indefinitely. My patients and I have proven it! - Dr. Bailey, 64-year-old dermatologist.
Alternate either my Natural Lotion or my Natural Butter Cream with the routine in my Ultra-Fast Body Smoothing Kit. Trust me, this fends of dehydrated and flakey skin on your arms and legs!
The glycolic acid body lotion is my favorite part of the ULTRA-FAST BODY SMOOTHING TRIPLE ACTION SKIN CARE KIT. It honestly does miracles to smooth, hydrate and (cue the heavenly music) tighten crepey skin. I saw 100%+ improvement in my skin in just a matter of weeks. THAT's the miracle I was looking for. Lori
The bottom line for preventing dehydrated skin:
It takes work to hold water in your skin when the relative humidity is less than 85%. Replenish skin lipids with the moisturizers and oils. Bind water inside the layers of your skin with humectants. Pick products with the right ingredients for your skin oil production and for face versus arm, leg or body concerns. Knowing this will help you to keep your skin supple, dewy, soft and well hydrated no matter how dry the weather is, how old you are, or how oily your skin is.
Cynthia Bailey MD, Dermatologist
- Enamul Haque Mojumdar, Quoc Dat Pham, Daniel Topgaard & Emma Sparr , Skin hydration: interplay between molecular dynamics, structure and water uptake in the stratum corneum, Nature, Scientific Reports; volume 7, Article number: 15712 (2017) Published 16 November 2017
- Barry M. Popkin, Kristen E. D’Anci, and Irwin H. Rosenberg, Water, Hydration and Health Nutr Rev. 2010 Aug; 68(8): 439–458.
- Potts Russel O, et. al., Changes with Age in the Moisture Content of Human Skin, Journal of Investigative dermatology, 82;97-100, 1984
- James William D, Berger Timothy G, et. al., Andrews Diseases of the Skin, 12th Edition, Elsevier, Inc, 2016, page 76-77
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