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
- 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.
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.
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.
Frequently Asked Questions
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.
K Health has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references.
Common Questions About Streptococcal Pharyngitis. (2016).
Streptococcal Pharyngitis in a Two-Month-Old Infant: A Case Report. (2016).
Pharyngitis (Strep Throat). (2018).
Strep Throat: All You Need to Know. (2022).
Strep Throat. (2022).
Scarlet Fever: All You Need to Know. (2021).
The Effect of Childhood Infection on Hearing Function at Age 61 to 63 Years in the Newcastle Thousand Families Study. (2015).
What Child Care Providers Should Know About…Strep Throat and Scarlet Fever. (2009).