Every few months I get sores in the corners of my mouth. Can you explain what is happening?

These usually are not cold sores (herpes simplex). The sores you refer to commonly occur in people with braces and those on Accutane. Stress may also be a factor.

Because the sores you describe respond readily to antifungal creams such as clotrimazole and terbinafine, many dermatologists feel the problem is due to the presence of yeast. Next time one of these sores or cracks develops, try applying one of those over-the-counter creams three to five times a day starting with the first indication of a problem. The problem should clear up in a few days. If not, make an appointment to see your dermatologist.