DEAR DOCTOR K: I've been under the weather for a few days. This morning I blew my nose and saw greenish mucus, so I called my doctor and requested antibiotics. He refused. Why?
DEAR READER: Your doctor is correct not to prescribe antibiotics based on the color of your mucus alone. Despite what many people think, you cannot rely on the color or consistency of nasal discharge to distinguish viral from bacterial sinus infections. That's an important distinction because only bacterial infections respond to antibiotics.