Strep Throat in Babies: What You Need to Know

By Zina Semenovskaya, MD
Medically reviewed checkmarkMedically reviewed
March 25, 2022

More than 11 million people in the U.S. get strep throat every year. 

This highly contagious sore throat is caused by bacteria called Streptococcus pyogenes, or group A strep, and accounts for around 5-15% of sore throat cases in adults and 15-30% in children. 

The infection is less common in infants, but babies can get strep throat. In this article, I’ll talk about how common strep can be in babies, how children can contract it, and its symptoms.

I’ll also outline some precautions you can take, explain how strep is treated, and tell you when to see a doctor or other healthcare professional about your baby’s health.

Strep Throat in Babies

Babies and toddlers under the age of three rarely get strep throat.

Strep is most common among school-age children ages 5-15.

In the rare case that a baby does get strep throat, it’s critical to be able to recognize the symptoms and identify the root cause.

Causes of strep throat in young children

In most cases, very young children pick up strep from close contact with a carrier at home, school, or in a daycare setting.

This person may have symptoms of strep or not—when they don’t, they’re an “asymptomatic carrier.”

However, strep is much more likely to be spread from a person who is actively showing symptoms than one who is not.

Group A strep often lives in the nose and throat, and an infected person will spread the bacteria by coughing, sneezing, and talking, which creates small respiratory droplets.

When another person breathes in those droplets, they can get infected.

Less commonly, strep can spread from bacteria housed in infected sores on the skin, which can also be caused by group A strep.

A child can become infected with strep by:

  • Breathing in respiratory droplets contaminated with bacteria
  • Touching anything with respiratory droplets on it, and then touching their nose or mouth
  • Touching fluid from sores on someone’s skin, and then touching their nose or mouth  
  • Sharing dishes with someone who is infected with strep
  • Eating food handled by someone with an active group A strep infection

The time between when a child is exposed and when they begin to show symptoms (called the incubation period) is two to five days.

Most people are contagious before symptoms become apparent.

Strep throat is a bacterial infection, not a viral infection.

There are, however, viral infections which can mimic strep. To determine if your baby’s sore throat is strep throat, a rapid strep test is the best option if strep symptoms are present.

This test involves a physician using a cotton swab to take a culture from the throat, which is then tested for strep. 


Some children show no symptoms of strep throat infection at all.

Others may display a host of symptoms.

However, most children have a select set of the most common symptoms associated with strep throat:

  • Sore throat that typically comes on suddenly
  • Pain when swallowing (may cause a refusal to eat in babies)
  • Fever (considered 100.3 degrees Fahrenheit or higher)
  • Red and swollen tonsils that may show visible streaks of pus or white patches (though these may not be present or visible in an infant)
  • Tiny, red spots (petechiae) on roof of the mouth
  • Swollen lymph nodes under the jaw in front
  • Headache
  • Stomach pain and/or nausea and vomiting

Strep throat infections are not usually associated with symptoms like a runny nose, sneezing, or a cough.

If your child has these cold-like symptoms, they are more likely to have a viral infection or allergies rather than strep throat.

Understanding the difference is important, since strep throat is treated with antibiotics, but antibiotics won’t help with a viral infection or allergies. 

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Precautions and Risks

Since strep can be dangerous to very young babies, it’s critical to use preventive methods even though their risk of catching it is lower than older children or adults. 

Is strep throat contagious?

Yes. Strep throat is a highly contagious disease. People with symptoms can easily pass it to anyone they come in close contact with.

Contagion begins before symptoms show up, and lasts until 12 hours after antibiotic treatment has been started. 

Complications when left untreated

If strep throat is left untreated, the bacteria can rarely spread to other parts of the body.

Some children who have strep repeatedly suffer from chronic tonsillitis, and end up having to have their tonsils removed.

This can put them at greater risk of upper respiratory infections as they grow older.

Untreated strep can also cause scarlet fever. Scarlet fever usually results in a rash that appears in the neck, underarms, and groin area.

The rash starts as flat spots, then hardens into sandpapery bumps.

Before antibiotics were widely available, complications from scarlet fever caused somechildren to go deaf.

Rheumatic fever is another possible complication of untreated strep. Rheumatic fever causes swelling of the joints and heart valves, and can be serious.

Untreated rheumatic fever can lead to kidney failure. 

Sometimes the rapid strep test can cause a false negative result.

However, if there is concern that a baby does have a strep infection, a throat culture can be done for confirmation.

This involves swabbing the back of the throat and creating a culture that is allowed to grow.

The culture is then examined to confirm whether strep bacteria are present. 

Preventing strep throat

To keep your baby safe from strep, wash your hands often.

Try to keep the baby away from older kids or adults who may have strep. Practice strict food safety.

And if you suspect you have strep, consider wearing a mask around your baby until you have been diagnosed and taken antibiotics.

Treatment and Relief

Most sore throats aren’t strep, but simply a cold virus.

However, if strep is confirmed, treatment can begin immediately and you can do extra things to make your child more comfortable.


The first line of treatment for group A strep is antibiotics. The first choice is penicillin or amoxicillin, both of which are tolerated well by babies.

If the infection turns out to be resistant to these antibiotics, or your baby is allergic, others can be used.  

How can I make my child feel better?

Giving your child warm fluid can help soothe their throat and also keep them hydrated.

Breastmilk or formula are good choices, depending on the baby’s age and feeding habits.

Setting up a humidifier in their room can also soothe their symptoms.

If antibiotics cause upset stomach or vomiting, ask your doctor for advice on safe medications to help your baby tolerate the medication, or if an injection instead of the liquid may be more appropriate. 

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When to See a Doctor

If you have strep and suspect you have transmitted it to your baby, or a child in your baby’s daycare has strep and your child has symptoms, talk to your doctor.

Getting a strep test as soon as possible can make sure that they’re diagnosed quickly and that there is no delay in treatment.

Antibiotics should generally not be given without a confirmed positive test for strep, so have your baby evaluated right away if your baby is at risk for the infection.

If your child starts to run a high fever, isn’t eating and drinking normally, or breaks out in a rash, visit their doctor. Babies can become sick very quickly, but usually respond well to treatment. They can be feeling better and back to normal activities quickly.

How K Health Can Help

Did you know you can access online urgent care with K Health?

Check your symptoms, explore conditions and treatments, and if needed, text with a healthcare provider in minutes. 

K Health’s AI-powered app is based on 20 years of clinical data.

Frequently Asked Questions

How do I know if my baby has strep throat?
If you know your baby has been exposed to strep, and they show any of the following symptoms, get them tested right away to check for strep. Potential signs of strep include: If your baby is refusing to eat or drink, has swollen lymph nodes under the jaw, or cries when they swallow. If your baby has other symptoms like a cough, sneezing, or a runny nose, it is much more likely to be a viral infection.
What happens if a baby gets strep throat?
Since babies rarely get strep, they may be infected for a number of days by the time you realize something is wrong. In severe cases, they may become dehydrated due to refusing to eat and drink. Untreated, strep throat can lead to complications such as scarlet fever or rheumatic fever.. Fortunately, antibiotics typically cause a rapid improvement in symptoms and can also prevent these complications if given in a timely manner.
Can a child under 2 get strep throat?
Yes, but it is rare. The fact that it is rare can give you some peace of mind when your baby becomes ill—the odds are it is just a common cold—but knowing the symptoms of strep throat can help you be prepared and take your baby in for testing right away if you’re concerned.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Zina Semenovskaya, MD

Dr. Semenovskaya specializes in emergency medicine, and received her medical degree from Weill Cornell Medical College. She is currently the medical director at Remote Emergency Medicine Consulting, LLC and splits her time working clinically as an emergency medicine attending in California and Alaska. She is the first of our doctors to be fluent in Russian.