Your skin protects you by producing a coating (a mix of oil, lipids and dead skin cells) that forms a seal and locks out viruses, bacteria and other tiny invasive agents. This protective layer pulls double duty -- not only does it keep bad things out, it helps keep your skin's moisture in. This gives your skin a healthy look and makes it soft to the touch.
But in addition to uncontrollable factors such as wind, sunlight or dry winter air, we do plenty of things ourselves that disturb or diminish that oily layer of protection on our skin.
When we bathe too often or scrub too hard, we strip away the oils we count on for skin protection. Some medications also dry out your skin as a side effect. In most cases, dry skin itself is no reason to cease treatment for the more serious affliction, but that knowledge alone won't make you less itchy or flaky.
And just what are those flakes? As a skin cell ages, it flattens (in part by losing its nucleus) and migrates outward toward the surface of your skin. Once there, it joins other flattened skin cells in forming a suit of skin-cell armor. Normally, these cells will slough off in small clusters. Dry skin is usually the result of these clusters clumping into larger bunches, which then appear as flakes of skin.
Dry skin is a malady unto itself, and it can also be a sign of a skin condition such as atopic dermatitis (a common skin allergy) or psoriasis (dry, flaky skin caused by amped-up splitting of skin cells). Skin dryness can accompany other health problems unrelated to your skin, such as diabetes or kidney disease.
Advanced treatment for these conditions may involve oral or topical drugs, such as corticosteroids or calcineurin inhibitors, which suppress the skin's immune response in order to end inflammation. As effective as these treatments may be, however, patients run the risk (especially over time) of experiencing side effects. In order to lower the risk of side effects (or to stop them once they've started), doctors may alternate treatments with emollients. Even used alone without other treatments, emollients can go a long way toward moisturizing and softening your skin, repairing the external barrier, and helping to protect your skin -- and you -- against the elements.
So what exactly is an emollient?
Emollients to the Rescue
There are two basic categories of moisturizer: humectants (which, like glycerin soap, absorb water from the air) and emollients.
Emollients soften skin in part by delivering the goods directly. Unlike a humectant, emollients bring moisture to your skin via the composition of the product itself. Carrier oil, urea and man-made substances such as silicone oils and isopropyl myristate are all emollients that you might see on product labels. One moisturizer will often contain several different types of emollients (and possibly humectants as well).
Emollients consist primarily of one of two things: oil or water. Oil-based emollients are greasier to the touch, are more easily seen on the face after application and stick around longer than water-based emollients. Water-based emollients are easier to apply and make less of a mess.
Dry skin can be the result of a problem with your skin's barrier. When detected by the body, this problem can result in an immune system response that causes inflammation and redness. When you apply a moisturizer that contains an emollient, you are soothing and healing the external barrier layer, which in turn will tell the immune system to relax and the inflammatory response to cease.
One of the main functions of an emollient is to trap moisture in the skin. However, if you don't properly apply an emollient, you may just wind up trapping moisture outside of the skin, leading to more problems with dryness. For this reason, it's important to apply an emollient cream when you already have some moisture on your face, hands or any other part of your body you are treating. A good time to apply an emollient is after bathing. Make sure you haven't completely dried off when you apply the emollient, thus trapping the external water beneath the artificial layer of oil you are applying. Otherwise, you'll be sealing in dry skin and preventing moisture from penetrating the emollient layer.
Emollients not only help moisten your skin and trap moisture within, they also reduce the need to use more potent medications that may cause a negative reaction, especially when used over a long period of time. Your dermatologist will know which course of action is best to treat your dry skin, but proper use of an emollient cream is a safe treatment you can undertake right away, and one that usually delivers results.
For lots more information on emollients and skin care, see the next page.
Related HowStuffWorks Articles
- Alai, Nili N, MD, FAAD. "Atopic Dermatitis." (Sep. 12, 2009)http://www.medicinenet.com/atopic_dermatitis/article.htm
- Alai, Nili N, MD, FAAD. "Psoriasis." (Sep. 12, 2009)http://www.medicinenet.com/psoriasis/article.htm
- American Academy of Dermatology. "Moisturizing and Cleansing Key to Treating Atopic Dermatitis." Mar. 2, 2006. (Sep. 13, 2009)http://www.skincarephysicians.com/eczemanet/moisturizing_cleansing.html
- Griffin, Morgan R. "What's Causing Your Dry Skin Problem?" (Aug. 5, 2009)http://www.webmd.com/skin-problems-and-treatments/features/whats-causing-your-dry-skin-problem
- Lodén, Marie; Maibach, Howard I. Dry skin and moisturizers: chemistry and function. CRC Press, 2000. ISBN 0849375207, 9780849375200.http://books.google.com/books?id=JpfgVgb62nsC&printsec=frontcover&source=gbs_navlinks_s#v=onepage&q=&f=false
- Lodén, Marie. "Role of Topical Emollients and Moisturizers in the Treatment of Dry Skin Barrier Disorders." American Journal of Clinical Dermatology. Nov. 2003.http://adisonline.com/dermatology/pages/articleviewer.aspx?year=2003&issue=04110&article=00005&type=abstract
- L'Oréal. "The epidermis." (Sept. 14, 2009)http://www.skin-science.com/_int/_en/topic/topic_sousrub.aspx?tc=SKIN_SCIENCE_ROOT%5EAN_ORGAN_REVEALED%5ETHE_EPIDERMIS&cur=THE_EPIDERMIS
- Mayo Foundation for Medical Education and Research. "Dry skin." (Sep. 10, 2009)http://www.mayoclinic.com/health/moisturizers/SN00042
- Proksch, E. "The Role of Emollients in the Management of Diseases with Chronic Dry Skin." Skin Pharmacology and Physiology. Jan 11. 2008.http://content.karger.com/ProdukteDB/produkte.asp?typ=pdf&doi=112957
- Radoja, Nada; Gazel, Alix; Banno, Tomohiro; Yano, Shoichiro; Blumenberg, Miroslav. "Transcriptional profiling of epidermal differentiation." Physiological Genomics. June 16, 2006. (Sep. 10, 2009)http://physiolgenomics.physiology.org/cgi/content/abstract/27/1/65
- Snowdrift Farm. "Emollients & Humectants." (Aug. 5, 2009)http://www.snowdriftfarm.com/emollients_and_humectants.html
- Wille, John J. Skin delivery systems: transdermals, dermatologicals, and cosmetic actives. Wiley-Blackwell, 2006. ISBN 0813808480, 9780813808482.http://books.google.com/books?id=xBe1RM6flrMC&printsec=frontcover&source=gbs_navlinks_s#v=onepage&q=&f=false