Q: My underarm skin is raw and itchy. How can I protect against odor without making things worse?
A: Women come into my office all the time complaining about redness, itching, and burning under their arms. Sometimes the cause is as simple as a dull razor nicking the skin, but more commonly a product is to blame. Most deodorants, antiperspirants, and shaving creams contain fragrance, a big-time allergen. Plus, salts and acids in antiperspirants can upset skin, as can your own sweat and the bacteria it breeds.

The solution? Treat the irritation for three to five days with an over-the-counter hydrocortisone cream. Once it subsides, keep skin in the clear by replacing your razor blade every two weeks; switching to alcohol- and fragrance-free products with soothing ingredients, like aloe; waiting 20 minutes after shaving before applying deodorants and antiperspirants; and wearing breathable cotton tops as much as possible. If the problem persists, see your dermatologist: It could be a bacterial or fungal infection.

Doris Day, MD, is a dermatologist and professor at NYU Medical School.