Am Fam Physician. 1998;58(6):1345
See related article on upper respiratory tract infections in children.
What causes a runny nose during a cold?
A runny nose usually starts when a cold is starting to get better. When the cold virus first infects the nose and sinuses, the nose starts making lots of clear mucus. This mucus helps wash the virus out of the nose and sinuses. After two or three days, as the body fights back, the mucus changes to a white or yellow color. As the bacteria that usually live in the nose grow back, they change the mucus to a greenish color. This is normal. It doesn't mean your child has an infection that needs to be treated with medicines like antibiotics.
Does a runny nose need to be treated?
No. Runny nose, cough, fever, headache and muscle aches may bother your child during a cold, but medicine won't make them go away faster. Using a cool mist vaporizer or giving your child an over-the-counter decongestant medicine may help. Check with your doctor to see which medicines are okay to use.
Why not take antibiotics?
Taking antibiotics that your body doesn't really need can be harmful. After each antibiotic, your child is more likely to have resistant germs in his or her nose. If your child gets infected again, it's more likely to be with these resistant germs. Resistant germs aren't killed by the usual antibiotics. If your child gets infected with a resistant germ, it might be necessary to use more expensive and powerful antibiotics or even antibiotics that have to be given in the hospital. Since a runny nose generally gets better by itself, it's best to wait and take antibiotics only when necessary.