Q. How long is a topical medication effective? I think I have had my tube for a while, and it isn't working.

To treat rosacea, dermatologists often initially prescribe oral antibiotic tablets to bring the condition under immediate control. However, taking more than one oral medication for different conditions may produce an adverse reaction, according to Dr. H. Irving Katz, professor of dermatology at the University of Minnesota, speaking at a recent meeting of the American Academy of Dermatology.

Q. I suffer from regular acne in addition to rosacea. Is this common?