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Note: This post is part of Mary Carpenter’s “winter series,” updates of her earlier stories on cold-weather well-being.
FOR DRY-SKIN sufferers, below-average temperatures predicted for the North and East this winter may present greater challenges.
While PhDs at cosmetics companies discuss at length the scientific principles behind their expensive potions, ever since a university-based dermatologist recommended the cheap and simple combination of mineral oil and lanolin, I’ve concocted my own brew.
Over more than 30 years, I’ve made only a few alterations—dropping in a little almond oil after friends described the odor as somewhere between sheep and urine; switching for a reason I can’t remember from mineral oil to petroleum jelly; and adding a few glops of some commercial preparation like Lubriderm or Eucerin to more easily mix in the heavy lanolin.
Although most friends brave enough to sample the brew find it too greasy, nothing has worked better for me, particularly when indulging in long, hot baths and showers (ill-advised for those with dry skin), but mostly because of dry air despite regular efforts to increase indoor humidity.
The best potions for very dry skin have the fewest ingredients—to reduce the likelihood of a sensitivity reaction. Hypersensitivity often accompanies dry skin, which is thinner and has lost some of the protection from lipids that act as mortar between skin cells, UCLA dermatologist Emily Newsom told SELF magazine.
Thinner skin creates a more permeable barrier for dry air to attack, makes the skin underneath more vulnerable—and makes it easier for moisture to escape. “You want to avoid what we call alligator skin,” Manhattan dermatologist Sapna Palep told New York Magazine. “Once it starts cracking like that…just using moisturizer isn’t going to cut it.”
Moisture is delivered to the skin via blood vessels that supply the skin’s middle layer, the dermis; from there it travels upward through the outer level, the epidermis, a bricks-and-mortar type membrane—before evaporating.
The drier the air due to low outdoor temperatures and overheated interiors, the more moisture it pulls from the skin—and the less water the epidermis can retain. (The third and lowest level of skin is the hypodermis or fatty layer.) Xerosis, or dry, flaky skin, is official when the skin’s moisture level dips below 10%.
To stay moist, what the skin needs is the unlikely sounding combination of oil and water: moisturizers work best when applied after bathing—when the water ingredient is already there —after the skin is blotted but not rubbed dry.
“Applying an oily substance to the skin without also resupplying it with water…is ineffective: you’d just end up with greasy skin that is still dry and cracked,” according to the Harvard Health Letter. “One reason for the proliferation of moisturizers is the continuing search for a mix of ingredients that holds in water like petrolatum but feels nicer on the skin.”
But there is no consensus regarding the definition of a moisturizer…a neologism coined by Madison Avenue,” according to dermatology researcher Anisha Sethi.
Traditionally, oily materials have been applied to the skin “to inhibit trans-epidermal water loss (TEWL)” by replacing the lost barrier.
Such oily materials, called occlusives—notably mineral oils and petrolatum—diffuse into the intercellular levels where they help bolster the bricks-and-mortar structure and form an evaporation-blocking barrier. Among occlusives, petroleum jelly has a “water vapor loss resistance” 170 times that of olive oil and reduces TEWL by more than 98%, compared to lanolin and mineral oils at 20-30%.
Humectants, another category, work by attracting moisture to the skin and keeping it there—“basically the opposite of occlusive and emollients which don’t like water,” writes Julia Calderone at Business Insider.
“But beware,” says Calderone. “In dry conditions, humectants can draw moisture from the younger, moist cells in the lower layers of the skin instead of pulling moisture from the air. Minimize this by pairing a humectant with an occlusive, which keeps the moisture in.”
The third category, emollients, include their own water and “penetrate the skin making it feel soft and flexible,” she explains. Depending on the amount of water added, emollients range from lotions to creams to ointments: for lotions, water is the base with oil added, advised for normal to slightly dry skin; creams contain about 50% of each, water and oil; and ointments start with oil, mixed with about 20% water— absorbed more slowly and staying on the surface longer for better protection, but often sticky and greasy.
Because adding water increases the likelihood of spoiling, some potions need more preservatives. And “since preservatives can stink, we add fragrances to mask the unpleasant smell…the more water content a product contains, the more likely it is for bacteria to form, so the higher the preservative and fragrance content,” according to Dermatology Alliance —which is why ointments can be easier on sensitive skin as well as less likely to go bad.
In one rating system assessing the 10 most popular lotions, the “hands-down” vote went to Aveeno Daily Moisturizing Lotion. The runner up was CeraVe Moisturizing Lotion, which is “even lighter than our pick…more expensive due to ‘healing’ ingredients even though research suggests they make little difference.”
For drier skin, dermatology sites recommend oils, including Neutrogena Light Sesame Oil and Alpha-Keri Oil. The most anecdotally well-liked and the one I use as backup is Aquaphor Advanced Therapy Healing Ointment—and for lips, the Repair and Protect Lip Balm—because the ingredient lists are shorter than most.
Specific ingredients that might affect those with sensitive skin include humectants like hyaluronic acid, which can burn; and lactic acid, an exfoliant—both found in different versions, for example, of Cetaphil, another anecdotally popular potion. For testing new potions, experiment with a little behind the ears several times and then alongside one eye before moving onto the rest of the face.
Also, keep indoor temperatures down, and use humidifiers to moisten the air. Believing that many people overdo their body-care routines, dermatologists suggest limiting the use of cleansers to private parts and underarms. Showers should last less than five minutes—in warm water. And take hot baths only when in dire need of comfort.
—Mary Carpenter
Every Tuesday, well-being editor Mary Carpenter reports on health news you can use.