For Clinicians | Strep Throat vs. Sore Throat

For Clinicians | Strep Throat vs. Sore Throat

Do You Need Antibiotics?

By Dr. Jamie Wilkey, PharmD — Director of Clinical Strategy, Jase
Medically reviewed and edited by Kristen Carpenter, PA-C

Most sore throats don’t need an antibiotic. Most of us already know that.

What’s harder to keep straight is the one patient who does, and what happens if that visit gets waved through like all the others. A kid with a sore throat, no cough, tender glands, running a fever, looks almost exactly like the kid down the hall with a garden-variety virus. The difference matters for antibiotic stewardship and, more importantly, for their health. Untreated Group A strep can progress to rheumatic fever: permanent heart valve damage that can show up weeks after the sore throat is long forgotten. Rheumatic fever is rare enough in the US that a lot of us learned about it as a historical disease that isn’t around anymore. But, it isn’t gone. It’s just rare enough, and quiet enough, that it’s easy to lose track of why the testing and treatment ritual around strep exists.

Today we’re talking about the tool that resolves that tension: the Centor score (McIsaac-modified for kids), what it tells you, and why the treatment on the other side of a positive test hasn’t changed in decades.

Do you need antibiotics for a sore throat?

Most of the time, no. The majority of sore throats, especially in adults, are viral. As you know antibiotics don’t affect a virus, and prescribing one anyway doesn’t get the patient better faster. It just adds an unnecessary drug, and an unnecessary risk, to their day. And contributes to antimicrobial resistance.

But roughly 5-15% of adult sore throats, and 20-30% of pediatric cases, are Group A strep. Symptom judgment alone doesn’t reliably separate the two: exudate can show up with mono, fever can show up with either, and “it just looks bad” isn’t a diagnostic criterion. The actual clinical problem isn’t “treat everyone” versus “treat no one.” It’s how to tell, reliably, which patient in front of you is which.

The four-question tool: the Centor score

The Centor score, McIsaac-modified with an age adjustment, turns that judgment call into a short checklist:

• Tonsillar exudate
• Tender anterior cervical lymphadenopathy
• Absence of cough
• History of fever
• Age adjustment: add a point for ages 3-14, subtract a point for ages 45 and up

Add it up. The score runs from -1 to 5, and each end points to a different action. A score of 0 or below means under 10% odds of an actual GAS infection: treat it as viral, skip testing. A score of 4 or 5 means over 50% odds: test to confirm if you want, but treating before the result comes back is reasonable. Everything in between, 1 through 3, is the test-before-you-decide zone, where a rapid strep swab settles it.

Take a 52-year-old with a cough, no exudate, no tender nodes, and no fever: zero criteria met, minus one for age 45 and up, for a total score of -1, the bottom of the range. Skip testing. Now take an 8-year-old with exudate, tender anterior cervical nodes, no cough, and a fever: four criteria met, plus one for age 3-14, for a total score of 5, the top of the range. Test and likely treat.

Using this little checklist in practice cuts unnecessary initial antibiotic prescribing by close to half, without missing the strep infections that matter. It settles the question directly: which patient in front of you actually needs the prescription.

When to test, and when the rapid test needs backup

A score in the test-before-you-decide zone (1 through 3) means swab and run a rapid antigen detection test (RADT). 

• Positive RADT: treat. No backup culture needed, in adults or kids. The test’s specificity is high enough to act on directly.
• Negative RADT in children and adolescents: back it up with a throat culture before ruling out strep. RADT sensitivity isn’t perfect, and this is the population carrying most of the rheumatic fever risk.
• Negative RADT in adults: no backup culture needed. The downstream risk is low enough that a negative result can stand on its own.

In practice, a lot of this happens before you’re even in the room. Plenty of practices swab everyone with a sore throat during rooming now, since newer RADT platforms turn around a result in about 15 minutes, often faster than the visit itself. That’s fine: RADT specificity is high enough that a positive result still means treat, even in a patient who scored a 0 and never should have been swabbed by the letter of the algorithm. The score’s real job in that kind of workflow isn’t gatekeeping who gets tested. It’s telling you how much to trust a negative, and in whom.

Why penicillin, still, after all these years

Once you’ve got a positive result, the treatment hasn’t changed: penicillin V or amoxicillin for a full 10 days. Group A strep has never developed resistance to penicillin. Which is impressive since clinicians have been prescribing it for decades for this. There’s no clinical reason to reach for a macrolide or a cephalosporin here unless the patient has a true penicillin allergy.

The full 10 day course really does matter too. The rheumatic fever prevention data behind this whole guideline was built on the 10-day course, not a shorter one, and stopping early is still the most common way an adequately-treated strep infection turns into a recurrence.

The bottom line

Most sore throats are viral, and most clinicians already know not to reach for the prescription pad on symptoms alone. The Centor score turns that instinct into a number: four questions that tell you which patient is worth testing, and which one just needs reassurance and time. When the test comes back positive, the treatment hasn’t changed in decades: penicillin or amoxicillin for the full 10 days.

We built Jase on that same idea: don’t guess who needs antibiotics, use a real framework to decide. Appropriate medical preparation takes the same logic behind the Centor score, defined criteria instead of a feeling, and applies it earlier: deciding ahead of time which predictable, self-limiting conditions are safe to prepare for before symptoms even start. In no way a replacement for a clinician’s judgment call. Just that same judgment, applied sooner.

Sources

1. Centor RM, Witherspoon JM, Dalton HP, Brody CE, Link K. The Diagnosis of Strep Throat in Adults in the Emergency Room. Medical Decision Making. 1981;1(3):239-246.
2. McIsaac WJ, White D, Tannenbaum D, Low DE. A clinical score to reduce unnecessary antibiotic use in patients with sore throat. CMAJ. 1998;158(1):75-83.
3. Shulman ST, Bisno AL, Clegg HW, et al. Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of America. Clinical Infectious Diseases. 2012;55(10):e86-e102.
4. CDC. Clinical Guidance for Group A Streptococcal Pharyngitis.
5. Hamilton JL, McCrea L. Streptococcal Pharyngitis: Rapid Evidence Review. American Family Physician. 2024;109(4):343-349.
6. Gerber MA, Baltimore RS, Eaton CB, et al. Prevention of Rheumatic Fever and Diagnosis and Treatment of Acute Streptococcal Pharyngitis: A Scientific Statement From the American Heart Association. Circulation. 2009;119(11):1541-1551.