Antibiotics: When Do They Help?

Antibiotics are strong medicines that can kill bacteria. They have saved many lives and prevented bad outcomes. These drugs do not kill viruses. They only work on bacteria. Every day, doctors must decide if a child's infection is viral or bacterial. Here's how they do it:

Bacterial Infections

Much less common than viral infections. Antibiotics can help. Bacteria cause:

Some ear infections
Some sinus infections (not sinus congestion)
20% of sore throats which are Strep throats
10% of pneumonia (a lung infection)

Viral Infections

Most infections in children are caused by a virus. Antibiotics do not help. Viruses cause:

100% of colds. (Note: unless they turn into an ear or sinus infection. This happens with 5 to 10% of colds.)
95% of new coughs. (Note: asthma can also start with a cough.)
95% of fevers
80% of sore throats
90% of pneumonia. (Note: most cases in children are caused by a virus.)
99% of diarrhea and vomiting
Note: There are a few anti-viral drugs that can treat viral infections. An example is Tamiflu used for severe influenza.

Cold Symptoms that are Normal

Parents sometimes are worried about common cold symptoms. The symptoms below are not signs of bacterial infections. Nor, are they a reason to start antibiotics.

Green or yellow nose discharge. This is a normal part of getting over a cold. It is not a clue to a sinus infection.
Green or yellow coughed up phlegm. This is a normal part of getting over viral bronchitis. It is not a sign of pneumonia.
High fevers. High fevers (more than 104° F or 40° C) can be caused by a virus or bacteria.

Side Effects of Antibiotics

All antibiotics have side effects. Some children taking these drugs can get side effects. Examples are diarrhea, nausea, vomiting, or a rash. Loose stools occur because the drug kills off the good bacteria in the gut. If your child gets a rash, it can be from the drug. Your doctor has to decide if the rash is an allergy or not. The biggest side effect of overuse is called antibiotic resistance. This is when the germs are no longer killed by the drug. That's why we only use antibiotics if your child really needs one.

Giving Antibiotics for Viral Infections: What Happens?

If your child has a virus, an antibiotic won't get rid of the fever. It will not help the other symptoms. The drug will not get your child back to school sooner. It will not get you back to work any faster. If your child has side effects from the drug, he will feel worse.

What You Can Do

Save antibiotics for bacterial infections when your child really needs them
Don't pressure your child's doctor for an antibiotic
Treat your child's cold and cough symptoms with home treatment that works
Keep in mind that fever is fighting the infection. It also boosts the immune system to prevent future infections.

Barton D. Schmitt MD, FAAP