When I wear clothes made from synthetic fabrics, I seem to get itchy and uncomfortable. Could I be allergic to them? —R.L., Chevy Chase, Md.

Yes. Synthetic materials such as acrylic, elastic, and polyester can cause redness and itching in susceptible people, and they also tend to trap moisture, which can add to the discomfort. But because laundry detergent can irritate the skin as well, the simplest first step is to try a mild detergent made for sensitive skin. If that doesn't help, a dermatologist can test to see if you're allergic to synthetic fabrics. If you are, avoid them in favor of natural fibers like cashmere, cotton, linen, or silk. For items where some elastic is unavoidable, such as bras and underwear, look for labels that say "100 percent cotton" and indicate that the elastic has a layer of cotton over it.

This article first appeared in the October 2008 issue of Consumer Reports On Health.