If your child has a sore throat, cough, or runny nose, you might expect the doctor to prescribe antibiotics. But most of the time, children don’t need antibiotics to treat a respiratory illness. In fact, antibiotics can do more harm than good. Here’s why:

Antibiotics fight bacteria, not viruses.

If your child has a bacterial infection, antibiotics may help. But if your child has a virus, antibiotics will not help your child feel better or keep others from getting sick.

• The common cold and flu are both viruses.
• Chest colds, such as bronchitis, are also usually caused by viruses. Bronchitis is a cough with a lot of thick, sticky phlegm or mucus. Cigarette smoke and particles in the air can also cause bronchitis. But bacteria are not usually the cause.
• Most sinus infections (sinusitis) are also caused by viruses. The symptoms are a lot of mucus in the nose and post-nasal drip. Mucus that is colored does not necessarily mean your child has a bacterial infection.

Antibiotics do not help treat viruses and some infections.

Some cases of the flu are both viral and bacterial. For these cases, antibiotics may be needed. Sometimes bacteria can cause sinus infections, but even then the infection usually clears up on its own in a week or so. Many common ear infections also clear up on their own without antibiotics.

Some sore throats, like strep throat, are bacterial infections. Symptoms include fever, redness, and trouble swallowing. However, most children who have these symptoms do not have strep throat. Your child should have a strep test to confirm that it’s strep, and then, if they’re needed, the doctor will prescribe antibiotics.

Antibiotics have risks.

Side effects from antibiotics are a common reason that children go to the emergency room. These medicines can cause diarrhea or vomiting, and about 5 in 100 children have allergies to them. Some allergic reactions can be serious and life threatening. The misuse and overuse of antibiotics encourages bacteria to change, so that medicines don’t work as well to get rid of them. This is called “antibiotic resistance.” When bacteria are resistant to the medicines used to treat them, it’s easier for infections to spread from person to person. Antibiotic-resistant infections are also more expensive to treat and harder to cure.

When used incorrectly, antibiotics waste money.

Most antibiotics do not cost a lot. But money spent on medicines that are not needed is money wasted. In severe cases, infections that are resistant to antibiotics can cost thousands of dollars to treat.

When does your child need antibiotics?

Your child may need antibiotics if:

• A cough does not get better in 14 days.
• A bacterial form of pneumonia or whooping cough (pertussis) is diagnosed.
• Symptoms of a sinus infection do not get better in 10 days, or they get better and then worse again.
• Your child has a yellow-green nasal discharge and a fever of at least 102° F for several days in a row.
• Your child has strep throat, based on a rapid strep test or a throat culture. If strep is not diagnosed with a test, antibiotics should not be given. No test is needed if your child has a runny nose and cough as well as a sore throat. Those are symptoms of a different virus.
• For infants younger than 3 months of age, call your pediatrician for any fever above 100.4° F (38° C). Very young infants can have serious infections that might need antibiotics.

Source: 2017 Consumer Reports. Developed in cooperation with the American Academy of Pediatrics.