If you frequently get unexplanned itchy rashes or bumpy breakouts, consider these possible culprits.

If you have sensitive skin, and often experience breakouts, you may have atopic dermatitis, or skin allergies.

Dermatitis can result in a variety of skin problems, depending on what triggers your reaction. Even if you're not truly allergic, you may be especially sensitive to chemicals, fibers, and other substances that you are exposed to on a regular basis. For some people, emotional ups-and-downs can cause skin eruptions.

Skin breakouts can take the form of rashes, hives, bumps, swelling, and discoloration. For very sensitive people, it doesn't take much to trigger a reaction. Substances that don't ordinarily bother most people, such as shampoos, cosmetics, hair dye, and wool clothing, can be very irritating to someone with skin allergies or sensitivities.

People who are allergic to the metal nickel commonly get a rash if they wear metal costume jewelry, such as watches or earrings, or clothing with metal studs that contain nickel. But researchers at the Ohio State University Wexler Medical Center (OSUWMC) found that people who are allergic to nickel can also develop itchy skin rashes from trace amounts of the metal found in their food.

These tiny amounts of nickel, found in whole grains, nuts, soy, and legumes (dried beans), as well as in stainless steel cooking utensils and canned foods, can accumulate in the body over time, until they reach a level that causes the immune system in an allergic person to react.

Chemicals that are used to process rubber, natural rubber latex, and elastic products, such as your yoga mat or cell phone case, can cause rashes associated with contact dermatitis. The long list of products that may contain natural rubber latex includes underwear, sneakers, socks, pantyhose, diaphragms, condoms, rubber bands, erasers, and many products used by doctors, dentists, and other medical professionals.

Other substances, such as those used to dye or otherwise treat fabrics, or to add fragrance to cosmetics and cleaning products, can also cause rashes in sensitive people. Sometimes the causes of breakouts are confusing and difficult to pin down.

"One of the most frustrating things about the response to nickel allergies from food sources is that the patients who were getting breakouts were trying to eat healthier foods," says Matthew J. Zirwas, MD, director of the Contact and Occupational Dermatitis Center at OSUWMC. "Yet, for this unique group, it was the healthier foods that were causing the problem."

If you suspect you have allergies or sensitivities, especially if you can't figure out what is causing them, see an allergy and asthma specialist or dermatologist for an accurate diagnosis, appropriate treatment and advice, or referral to another specialist, if necessary.

In some cases, a rash may be due to an underlying medical condition other than skin allergies. Autoimmune disorders such as lupus, rheumatoid arthritis, and Kawasaki disease can also cause breakouts, anywhere on the body.

Michael J. Zirwas, MD, reviewed this article.



"Clothing Dermatitis and Clothing Related Skin Conditions," Washington State Department of Labor & Industries, last modified August 2001

"Latex Allergy-Information for Health Care Professionals," New York State Department of Health, last modified May 2012

"Rash of Nickel Food Allergies Linked to Healthier Diet," The Ohio State University Wexner Medical Center, last modified March 1 2012.