As reported by the New Haven Register, February 18, 2007.

Save Your Skin

By Abram Katz

All that stands between all of outdoors and all of your insides is a thin layer of skin cells that don’t like winter.

Cold weather drops the relative humidity, creating a dryness that rends skin. Lips chap, fingertips crack, foreheads flake and hands roughen into a mosaic of tiny cracks.

To make matters worse, it’s cold and windy outside and we wash our hands frequently to keep cold viruses at bay.

Moisturizing creams can help, but it’s not necessary spend a small fortune for oats, vitamin E (alpha, beta gamma and delta tocopherols), palmitic acid from cocoanut trees, soybean oil, propylene glycol (a chemical used in antifreeze that also absorbs moisture), or parabens to preserve all of that other stuff.

Plain old petroleum jelly will do the trick.

But why do we need any of these goopy products?

"The fundamental problem is that the upper most layer of skin, the stratum corneum, is impermeable. When it’s broken, it allows water to escape," said Dr. Kalman L. Watsky, dermatologist at the Hospital of Saint Raphael in New Haven.

Not enough water equals dry skin.

"When the relative humidity drops below 30 percent, dry skin becomes a problem," Watsky said.

Dry air also welcomes moisture from the skin and a dry wind desiccates the stratum corneum even faster.

We also shed cells from the stratum corneum constantly, as new cells take their place.

The cells of the stratum corneum lack nuclei and are completely keratinized, or filled with the same kind of protein that’s in hair and nails.

These cells are cemented together with lipids, or fat-like molecules. Washing with soap dissolves lipids, which allows water from deeper layers of skin to escape, Watsky said.

The cells also expand when they absorb water, which is why we get "prune" fingers after a long soak. When dry they shrink back to normal.

Stretching and shrinking repeatedly weakens the cells and creates cracks, Watsky said.

Moisturizing creams and lotions contain lipids, waxes or in the case of petroleum jelly, hydrocarbons, that seal moisture in. Most contain their own water, which is why they also have to contain emulsifying agents and other ingredients to keep the water and lipids from separating.

"The stratum corneum looks wimpy, but it’s our armor against the environment," said Dr. Jane Grant-Kels, chairman of the department of dermatology at the University of Connecticut School of Medicine.

"These cells have reached the pinnacle of their careers," she said.

The thickness of the stratum corneum varies from the palms and soles of the feet, (a thick 1.5 millimeters) to the thin eyelids, about 0.05 millimeters. Male skin is generally a bit thicker than female skin. At age 40, the skin starts to naturally thin and lipid production declines.

"In the winter the top layers of skin get dried out, thicken and crack. It’s very important to hydrate," she said. "It’s dry and cold outside and dry and hot inside."

Skin receives no relief.

One way to fight dry skin is to reduce bathing, Grant-Kels said.

However, one needn’t give up good hygiene to keep skin supple. Take a shower, she said, but it shouldn’t be too hot, too long or too soapy.

Pat yourself mostly dry. Don’t rub as if you were waxing a car. Then immediately apply a moisturizer, Grant-Kels said. This will seal in some water.

"Do this at least once a day," she said.

Take a warm shower, not hot, which will wash away more protective lipids. Keep it brief so your skin cells don’t expand and shrink, and unless you’ve been perspiring or working in a coal mine, there’s no need to wash every square inch of skin, she said.

Under the arms and below the waist is usually all that’s necessary, she said. Many women experience dry skin on their legs, and there is usually no need to wash them in soap unless they are dirty.

Our skin dries as we age because the body produces fewer lipids, and the blood supply to the outer layer of skin diminishes.

"It’s important to lubricate your skin with cream or lotion that you are not allergic to," Grant-Kels said.

Allergens could include fragrance, lanolin or vegetable products. Dry skin is itchy, but if you develop a rash you may be allergic to the moisturizer.

Putting cream on yourself after a shower, or on your hands or face is one thing, but what about chapped lips?

When lips are dry people lick them, which makes them worse, Watsky said. Saliva is also an irritant. Apply a product intended to moisturize lips and repeat during the day, he said.

Most lip treatments are waxy to avoid rapid dissolution by saliva.

Perhaps the worst consequence of dry skin are painful fissures and cracks that never seem to heal.

Put petroleum jelly or the moisturizer of your choice on your hands and other cracked areas before bed. If you leave the skin uncovered, the product will be wiped off. Gloves or mittens pose the same problem. Instead, wind plastic wrap around your hands before going to sleep. This will keep the product from rubbing off, Watsky said.

Dry skin also gets blamed for dandruff. In fact, a dry scalp will shed smaller flakes of skin.

Watsky said dandruff may be caused by overly active sebaceous glands, which are irritated by a type of yeast. Skin becomes inflamed and flakes come off.

If this is the case, shampoo containing an anti-fungal agent are available.

If dry skin, or other skin conditions become a major concern, consult a dermatologist.