Centor score
Probability of group A streptococcal pharyngitis in adolescents and adults (≥ 15 years)
- DEGAM S3 Halsschmerzen
- NICE NG84
Sources last checked: 2026-10-13
Centor score
Probability of group A streptococcal pharyngitis in adolescents and adults (≥ 15 years)
Group A streptococci in ≈ 7 % (0), 12 % (1) and 21 % (2) of patients ≥ 15 years (Fine 2012; pooled 13 % in DEGAM). DEGAM and NICE recommend no antibiotic in this group, with symptomatic treatment and safety-netting advice.
For acute sore throat without red flags (scarlet-fever rash, suspected mononucleosis, immunosuppression, chemotherapy, severe comorbidity, another infective focus). Derived in adults in a US emergency department; even at 4 points, about half of patients do not have group A streptococci. The DEGAM S3 guideline is past its review date and under revision.
Interpretation
| 0–2 — low probability | Group A streptococci in ≈ 7 % (0), 12 % (1) and 21 % (2) of patients ≥ 15 years (Fine 2012; pooled 13 % in DEGAM). DEGAM and NICE recommend no antibiotic in this group, with symptomatic treatment and safety-netting advice. |
|---|---|
| 3 — intermediate probability | Group A streptococci in ≈ 38 %. DEGAM: if an antibiotic is considered, the guideline provides for a delayed prescription only. NICE (Centor 3–4) recommends considering an immediate or back-up antibiotic. |
| 4 — higher probability | Group A streptococci in ≈ 57 %. DEGAM names a delayed or immediate antibiotic as options. NICE recommends considering an immediate or back-up antibiotic. |
What is the Centor score?
The Centor score estimates the probability that a sore throat is caused by group A streptococci from four clinical findings. Centor and colleagues derived it in 1981 from 286 adults in a US emergency department. It is used in DEGAM and NICE guidance to identify patients who are unlikely to benefit from antibiotics.
When to use it
- Acute sore throat (< 14 days) in patients aged 15 years and older.
- Deciding between no antibiotic, delayed prescription or immediate antibiotic.
- Structuring the conversation about the expected course and the small benefit of antibiotics.
When not to use it
- Red flags: scarlet-fever rash, suspected mononucleosis, immunosuppression, chemotherapy, severe comorbidity, or signs of another infection focus.
- Children under 15 — use the McIsaac or FeverPAIN score.
- Suspected peritonsillar abscess or systemically very unwell patients.
How it is calculated
| Criterion | Points |
|---|---|
| Tonsillar exudate | +1 |
| Tender anterior cervical lymphadenopathy or lymphadenitis | +1 |
| History of fever (> 38 °C) | +1 |
| Absence of cough | +1 |
Clinical pearls and limitations
- For acute sore throat without red flags (scarlet-fever rash, suspected mononucleosis, immunosuppression, chemotherapy, severe comorbidity, another infective focus). Derived in adults in a US emergency department; even at 4 points, about half of patients do not have group A streptococci. The DEGAM S3 guideline is past its review date and under revision.
- Even with 4 points, roughly half of patients have no group A streptococci — the score selects, it does not diagnose.
- Antibiotics shorten symptoms by only about 16 hours on average; complications are rare either way.
- DEGAM provides for a delayed prescription at most at score 3, and a delayed or immediate antibiotic at score 4.
- Fine 2012 (206,870 patients) found GAS prevalence of 7 % at 0 points rising to 57 % at 4 points.
Frequently asked questions
What Centor score needs antibiotics?
None automatically. DEGAM recommends symptomatic treatment at 0–2, a delayed prescription at 3, and a delayed or immediate antibiotic at 4; NICE considers antibiotics at 3–4.
What is the difference between Centor and McIsaac?
McIsaac adds an age correction (+1 for 3–14 years, −1 from 45 years) so it can be used in children.
Should I take a throat swab at a high Centor score?
In adults DEGAM does not require one routinely. In children aged 3–15 with a score ≥ 3, a rapid antigen test may support the decision.
Evidence and guidelines
- Primary source: Centor RM, Witherspoon JM, Dalton HP, Brody CE, Link K. The diagnosis of strep throat in adults in the emergency room. Med Decis Making 1981;1(3):239-246.
- Fine AM, Nizet V, Mandl KD. Large-scale validation of the Centor and McIsaac scores to predict group A streptococcal pharyngitis. Arch Intern Med 2012;172(11):847-852.
- DEGAM S3-Leitlinie Halsschmerzen (AWMF-Register 053-010), 2020, revidiert 12/2021 — Empfehlung 9.9 und Tabelle 8.2. Gültigkeit abgelaufen, in Überarbeitung.
- NICE NG84. Sore throat (acute): antimicrobial prescribing, 2018 — recommendations 1.1.5–1.1.11 and 'Terms used in the guideline'.
Have a follow-up question?
Medelix answers clinical questions from current guidelines and studies — every statement with its source.
Ask Medelix about the Centor scoreRelated calculators
Embed this calculatorFree to use on your website, intranet or teaching page. Copy the code below.
<iframe src="https://medelix.ai/en/embed/centor" title="Centor score – Medelix" width="100%" height="620" style="border:0;max-width:720px" loading="lazy"></iframe>
<p><a href="https://medelix.ai/en/calculators/centor-score">Centor score calculator by Medelix</a></p>For healthcare professionals and medical students. These tools support, and do not replace, clinical judgement. Always check results against the original source and your local protocols.