Q: My 5-year-old son has bad breath. What causes it?
A: Children can have smelly breath just like adults. Standard bad breath is blamed on air-borne chemicals the normal bacteria in the mouth make when they digest bits of liquid or solid food. Eating, drinking or rinsing the mouth cleans out the smelly chemicals, but only temporarily. The bacteria get busy again and in about three hours, the odor is back. The smell gets stronger as more time between eating or drinking elapses. You may have noticed that most people's breath smells the worst when they get up in the morning. Adults usually rinse or brush as soon as they get up. Children are not usually that sophisticated.
Occasionally breath odor is extraordinarily bad. If you think your child's breath can slay dragons, you should ask your doctor to examine him. Infections, especially of the nose, mouth and the throat area, or problems with teeth may contribute to bad breath.
If you notice an odor even when your son's mouth is closed or if he has bad breath and yellow or green mucus draining from a nostril an examination is particularly important. Sometimes a child puts a small object up the nose. It gets stuck and is forgotten. Eventually it becomes an infection site and begins to smell and will until removed.
Dr. Wilson is director of general pediatrics at the Johns Hopkins Children's Center; Dr. Joffe is director of adolescent medicine.