(Real Simple) -- Learn how to prevent and combat the worst winter skin symptoms and you'll feel as if spring had already arrived.
Dry, irritated skin is your body's way of sending an SOS signal -- and it's not just a matter of comfort.
"Well-moisturized skin provides a barrier that keeps out infectious bacteria, viruses, and fungi, and it protects against friction," explains Kelly M. Cordoro, an assistant professor of dermatology at the University of Virginia, in Charlottesville.
With a little knowledge, you can answer your skin's distress call and enjoy a smooth season.
The skin's moisture levels are controlled by lipids, oily substances produced by the outer layer of skin, the epidermis. An epidermis that is deficient in lipids allows water to escape from the skin and evaporate, causing dryness.
Skin regenerates on a monthly cycle. It sheds the dead, flattened cells that lie on its surface to make room for new, living cells to rise. If the dead cells don't shed as quickly as they should, thick, dry skin can form, says D'Anne M. Kleinsmith, a dermatologist in West Bloomfield, Michigan. This further impairs the skin's normal barrier function. Environmental irritants such as bacteria can then sneak in, causing inflammation.
Some body parts are more prone to dryness than others, depending on their concentration of oil glands. The greatest concentrations are on the face (especially around the forehead and the nose), the chest, and the back, which all tend to have little trouble with dryness.
The lower legs have few oil glands, which is why they dry out so easily. Lips have none, and unlike the skin on the rest of the body, lip tissue has no thick, protective outer layer, either. They are also constantly moisturized by saliva, then dried by breathing, which has an evaporative effect.
Evaporation also dries out hands (from washing) and feet (from sweating). The thicker skin on elbows and knees has trouble retaining water, and its constant exposure to friction is also drying.
Hydration is important not only for skin's health but also for its appearance, says New York City dermatologist Doris J. Day: "When skin is dehydrated, it droops and sags. It looks older, and wrinkles are more pronounced."
Causes of dry skin
Many different factors cause dry skin. Among them:
Age -- As estrogen production decreases in women, particularly as menopause nears, the skin produces fewer lipids. As you get older, cell turnover also slows down, resulting in more flakiness.
Genes -- Some people are more genetically predisposed to skin dryness than others. It could be as simple as having fewer oil glands. Or you could be one of the millions of Americans who suffer from eczema, a skin disorder that is often hereditary.
Weather changes -- Chilly temperatures, cold winds, low humidity, and dry indoor heat (particularly the forced-air type) cause water to evaporate from the skin because there is more water in your skin than in the air, says Cherie Ditre, an assistant professor of dermatology at the University of Pennsylvania School of Medicine.
Long, hot baths and showers -- Too much washing strips the skin of its protective layer of oil, causing it to become dry. Then, as the water evaporates from the skin, it pulls more valuable moisture from the epidermis with it. Cleansing with harsh soaps can also strip lipids from the skin and increase water loss.
Smoking -- Extremely toxic for the skin, smoking deprives the outer layers of oxygen and nutrients, as well as promoting premature wrinkling. In addition, "the smoke itself dries the skin's surface," says Jerome Z. Litt, an assistant clinical professor of dermatology at Case Western Reserve University, in Cleveland.
Bundling up in woolen clothing -- Scratchy materials can rub your skin the wrong way, disrupting the barrier that keeps moisture in and causing chapping. Real Simple: Long-lasting beauty solutions
How to winterproof your skin
Slightly adjust your skin-care routine and daily habits to ward off dryness. Cleanse your face just once a day -- at night, to remove dirt, impurities, and makeup -- and simply rinse it in the morning.
Alcohol dries the skin, so during the cold months, shelve products with high levels of alcohol, such as facial toners and astringents. Exfoliate your face and body once a week with a gentle scrub or a washcloth.
Take lukewarm showers and limit them to five minutes or less. "Just as you use hot water, soap, and scrubbing to get grease out of dishes, you can wind up removing natural oils from your skin by using these things during bathing," says Barbara R. Reed, a dermatologist in Denver. If you prefer baths, add colloidal oatmeal, which is moisturizing, soothing, and particularly helpful if your skin is chapped.
Replenish the moisture that you remove from your skin by washing. Drinking plenty of water isn't enough by itself.
"If you are well hydrated, the skin will be healthier, but it does not make a difference to the outer layers of the skin," says dermatologist Doris J. Day. "You still need to use a moisturizer on the surface."
During the colder months, moisturize your body at least twice a day -- immediately after showering and before bedtime. "The drier your skin, the thicker the lotion should be," Reed says. "If you are very dry, you should be dipping into a jar, not squirting lotion out of a bottle."
Put on thin white cotton gloves over moisturized hands. It's been said before, but this really works to heal very dry skin. Dampen your hands, apply a rich ointment, and then wear the gloves for a few hours. For rough patches, such as on elbows, lock in moisture with petroleum jelly.
Try a humidifier in your bedroom if you don't have one in your central heating system. But be vigilant about keeping it clean: "Different molds, fungi, and bacteria can grow in a humidifier," says Kelly M. Cordoro, an assistant professor of dermatology at the University of Virginia, in Charlottesville. To prevent yours from becoming a germ haven, change the water daily and clean it every three days.
Cover up before heading outside. Leather gloves keep hands from chapping (the leather provides a better barrier to moisture evaporation than cotton), and wax-based products like lipstick and lip balm provide moisture and wind protection. Just as you shouldn't wait until you are thirsty to drink water, don't wait until your skin and lips are dry before moisturizing.
Chronic health conditions -- Diabetes, thyroid disorders, kidney disease, and some other conditions can affect the skin's ability to retain moisture. Some medications -- including antihistamines, tamoxifen (for breast cancer), and certain antidepressants -- also cause dryness. Real Simple: Best drugstore beauty buys
• Curel Ultra Healing 24-Hour Daily Moisturizing Lotion for Extra-Dry Skin ($7.50 at drugstores) contains petrolatum, glycerin, and shea butter, a natural oil from the nut of the shea tree that prevents water loss from skin.
• Vaseline Intensive Rescue Moisture Locking Lotion ($5 at drugstores) is a daily moisturizer with glycerin and dimethicone, a silicone derivative that seals in moisture.
• Dove Pro-Age Body Cream Oil ($7.50 at drugstores, beginning in March) packs a triple punch with glycerin, olive oil, and mineral oil.
For treating dry skin
• Aveeno Skin Relief Moisturizing Lotion ($8 at drugstores) soothes with oatmeal and shea butter.
• Johnson's Nourishing Renewal Lotion ($5 at drugstores) replenishes essential oils that diminish in the skin over time and softens with shea butter.
• Olay Quench Therapy Body Lotion ($7 at drugstores) uses shea butter, olive oil, and palm oil, a natural ingredient that contains vitamins A and E. Real Simple: Best products for dry skin
• For treating severe dryness
• Elta Tar ($10, www.drugstore.com) treats eczema with petrolatum, paraffin, and mineral oil.
• Aquaphor Healing Ointment ($8.50 at drugstores) is a heavy-duty protectant that gives relief to raw, cracked skin.
• AmLactin 12% Moisturizing Cream ($13, www.drugstore.com) alleviates rough spots and rehydrates skin with lactic acid. E-mail to a friend
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