Since clothing is in close contact with your skin most of the day, it’s no surprise that your shirts, pants, and undies can cause skin problems.

Any kind of fiber can bring on a rash, but you’re more likely to get textile dermatitis from clothes made with synthetics such as polyester, rayon, nylon, spandex, or rubber. They don’t breathe as well as natural fibers, and they make you sweat more.

Often the source is the dye or other chemicals in the clothing. Formaldehyde resins used to make garments wrinkle-free or dirt-repellent can cause problems. So can dyes, glues, and chemicals used to tan, or create, leather. If you’re allergic to nickel, you might get a red, itchy reaction where your blue jeans button touches your skin. It has its own name: nickel dermatitis. Jewelry with nickel can cause it, too.

The combination of tight-fitting fabric and sweat can irritate your skin as it rubs against you. Doctors call this less common condition irritant dermatitis. It may look a lot like textile dermatitis, but the cause is different.