I am currently finishing up antibiotics for sinus and ear infections, and I am experiencing vaginal burning and irritation. Could these be related? What do I do for it?

--L.P.

Antibiotics are not like "smart bombs" that only hit the intended target. Antibiotics kill the bacteria causing your sinus and ear infections, but they also kill other, beneficial bacteria elsewhere in your body, including the vagina. "Good" bacteria in the vagina help maintain a system of checks and balances on other bacteria and yeast that can cause infection. If this balance is disturbed -- as it can be by the use of antibiotics -- yeast and pathogenic ("bad") bacteria can establish a foothold. The result is an infection with associated itching and burning. A discharge may occur as well.

If you have never experienced these symptoms before, it is important to see your gynecologist first for a proper diagnosis. Many women assume all itching and burning is due to a yeast infection, so they use over-the-counter yeast creams. Not all vaginal itching is yeast, however, and over-the-counter creams are ineffective against bacterial infections. If you have used one of these medications and your symptoms have not gone away -- or if they return -- then a doctor's visit is necessary. Discharges with a fishy odor are not characteristic of yeast, and these must be evaluated and treated by a doctor.

In the future, eating extra yogurt (with active cultures) or taking acidophilus while you are on antibiotics for another infection may help stave off this unpleasant vaginal itching and burning.