Step outside in winter and the skin is blasted by icy, frigid winds. Indoors, heated air further assaults the skin by sucking out moisture, leaving it dry, chapped, itchy and flaky.

Dry skin -- or xerosis -- can affect virtually everyone, said John Wolf, chairman of the Department of Dermatology at Baylor College of Medicine in Houston. People with sensitive skin and the elderly are particularly susceptible. As people age, a reduction in the hormone androgen, which stimulates the skin's oil glands, causes the skin to become drier.

Use of acne medications like Retin-A -- a synthetic derivative of vitamin A -- can make the problem worse. "The therapeutic aim of acne medication is to dry out the skin, and one can overdo the treatment," said Carmen Myrie Williams, associate professor of dermatology and pathology at George Washington University Medical Center.

Putting moisture back into the air -- particularly during the dry, winter months -- is one way to relieve the condition. Using a humidifier at night can really make a difference, said Stanford Lamberg, associate professor of dermatology at Johns Hopkins University School of Medicine.

A less expensive alternative to a humidifier is a steam vaporizer, which can be purchased for about $20. "It is the same thing you would do for a child who has a cold," said Lamberg.

Experts often advise people with excessively dry skin to bathe less often because frequent showers can strip the skin of its natural oils. Telling people not to bathe every day is not realistic. Using liquid cleansers instead of soap and applying a good moisturizer while the skin is still wet "makes a lot more sense than saying you can only shower on Saturday," said James J. Leyden, a professor of dermatology at the University of Pennsylvania.

Moisturizers range from lighter lotions to heavier creams and ointments. "The heavier the cream, the more effective it is," said Leyden.

But thicker creams -- like Vaseline petroleum jelly, which contains more oil -- are not as aesthetically pleasing. They feel greasy and can stain clothing and furniture.

George Washington University's Williams recommends choosing a moisturizer with the least amount of fragrance. The degree of dryness should dictate what type of moisturizer to select. Somebody with slightly dry skin should choose a lighter lotion, whereas someone with severely dry skin or eczema -- a skin inflammation -- should use heavier creams. "Often, people are very heavy-handed when applying these products," said Williams. "Apply a thin film so the skin feels moist without feeling greasy."

Skin researchers are investigating whether lotions made with lactic acid, a chemical similar to the citric acid found in grapefruits and oranges, can help dry skin. "Some studies show that lactic acid makes the skin hold on to water, makes it less dry, less stiff and may make the skin's outer layer less vulnerable to the damage caused by soap," Leyden said.

Some lotions containing lactic acid are available without a prescription.