Understanding Strep: Why Treating Under 3 Is Not Routine

Written By Sarah Van Houten

What is Strep Throat?

Strep throat is a throat infection caused by Group A Streptococcal (GAS) bacteria. It’s most common in school-aged children between 5 and 15 years old and adults can get it as well. 

Here’s the thing: 

Strep throat is less common in children under 3, and almost unheard of in babies under 1. In this younger age group, most sore throats are actually caused by viruses, not bacteria, so antibiotics don’t help.

Major Concerns

Strep isn’t just about sore throats; it can lead to RARE but serious complications:

  • Acute rheumatic fever – inflammation that can damage the skin, joints, heart, and brain.

  • Post-strep glomerulonephritis – inflammation of the filtering units of the kidneys (glomeruli).

BUT, and this is very important:

These complications are extremely rare and even more rare in children under 3. That's the reason why routine testing and treatment aren’t recommended for toddlers unless there’s a very specific reason. In fact, the Infectious Diseases Society of America (IDSA) specifically recommends against it.

Why are Doctors Cautious About Testing?

In older children, doctors often use tools like the Centor Score to help predict the likelihood of GAS and guide testing decisions. However, these are not validated for children under 3.

The standard throat culture or rapid antigen tests (RADT) are valid for children under 3, but these should be used only in patients with moderate to high clinical suspicion. Why? Because of carriers.

What about Carriers?

Up to 1 in 5 children carry strep in their throat without being sick.

This means:

  • A test could be positive even if the sore throat is caused by a virus.

  • Treating a carrier with antibiotics is unnecessary

  • Overuse of antibiotics can lead to increased side effects, antibiotic resistance, and disrupt gut health

So How Is Strep Diagnosed?

The test is a throat swab – quick but definitely not most kids’ favorite (cue gag reflex). There is usually a rapid test done (rapid antigen test or RADT)  - if positive that’s enough to treat. If negative, often a throat culture is sent to the lab and can show if there is any bacteria growing but this can take a few days to come back. 

  • Rapid test negative→ culture also negative - no strep 

  • Rapid test positive →  treat 

  • Rapid negative, culture positive -> often treat 

    In older kids, doctors use one of the scoring systems previously mentioned to decide if testing is needed. But in toddlers, it’s all about clinical judgment and only testing when it truly makes sense.

    When might testing your toddler make sense: they’ve been in close contact with someone diagnosed with strep and are symptomatic themselves. 

    The main goal of treatment in this age group is to prevent transmission to close contacts and in rare cases to decrease the severity and duration of symptoms - not for the prevention of complications like it is for older children 

How To Treat: 

If your pediatrician does test and finds true strep throat, treatment is safe, effective and well tolerated:

  • Penicillin V or amoxicillin for 10 days is still the gold standard.

  • Shorter treatments are being studied, but are not widely used yet.

  • Alternatives are available for children with a penicillin allergy 

Remember to ALWAYS finish the full course of antibiotics to avoid relapse or complications


TLDR

Strep throat is uncommon in children under 3 and does not cause the same complications as it does in older children so testing and treatment are not indicated. Unnecessary testing can lead to false positives and unnecessary antibiotic use. Antibiotics won’t help a sore throat if it’s a virus (which is usually is for kids under 3). Supportive care (rest, fluids, Tylenol or ibuprofen (if >6 months)) is usually all your toddler needs. If you suspect strep and there’s a clear exposure or signs, talk to your pediatrician.

  • References

    Cleveland Clinic. (2023, May 3). Why are strep tests avoided in children under age 3? Cleveland Clinic Health Essentials. https://health.clevelandclinic.org/why-are-strep-tests-avoided-in-children-under-age-3

    Di Pietro GM, Marchisio P, Bosi P, Castellazzi ML, Lemieux P. Group A Streptococcal Infections in Pediatric Age: Updates about a Re-Emerging Pathogen. Pathogens. 2024 Apr 24;13(5):350. doi: 10.3390/pathogens13050350. PMID: 38787202; PMCID: PMC11124454.

    Sharif MR, Aalinezhad M, Sajadian SM, Haji Rezaei M. Streptococcal Pharyngitis in a Two-Month-Old Infant: A Case Report. Jundishapur J Microbiol. 2016 May 9;9(5):e32630. doi: 10.5812/jjm.32630. PMID: 27540457; PMCID: PMC4976646.

    Martin, J.M. The Mysteries of Streptococcal Pharyngitis. Curr Treat Options Peds 1, 180–189 (2015). https://doi.org/10.1007/s40746-015-0013-9

    Tanz, R. R., Gewitz, M. H., Kaplan, E. L., & Shulman, S. T. (2020). Stay the course: Targeted evaluation, accurate diagnosis, and treatment of streptococcal pharyngitis prevent acute rheumatic fever. The Journal of Pediatrics, 216, 208–212. https://doi.org/10.1016/j.jpeds.2019.08.042



Sarah Van Houten

Sarah is a biomedical Engineer, PhD, advocate for evidence-based medicine, MPF summer intern and most importantly, a mom

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