What is the Centor score?

The Centor score (modified as McIsaac criteria) predicts the likelihood of Group A streptococcal (GAS) pharyngitis using clinical findings: (1) tonsillar exudates, (2) tender anterior cervical lymphadenopathy, (3) fever history, (4) absence of cough. The McIsaac modification adds age-based adjustments.

How is the Centor score interpreted?

Score 0–1: GAS unlikely (~5–10%), no testing or antibiotics needed. Score 2–3: Moderate probability (~15–35%), rapid antigen testing recommended. Score 4–5: High probability (~50%), empiric antibiotics or test-and-treat approach. Guidelines recommend throat culture confirmation for negative rapid tests in children.

Should you always test for strep with a high Centor score?

Guidelines vary. The IDSA recommends testing (rapid antigen ± culture) regardless of score and treating only confirmed cases. The ACP/ESCMID supports empiric treatment for scores ≥ 4 in some settings. Testing helps avoid unnecessary antibiotics and confirms diagnosis.

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Modifizierter Centor-Score (McIsaac)

Wahrscheinlichkeit einer Streptokokken-Pharyngitis (GAS) schätzen und Test-/Behandlungsentscheidungen leiten.

Kriterien

Alter

Tonsillenexsudate oder -schwellung (+1) Druckschmerzhafte anteriore zervikale Lymphadenopathie (+1) Fieber (Temperatur > 38°C) (+1) Fehlen von Husten (+1)

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Altersgruppe auswählen zum Scoring-Beginn.

≤ 0~1–2,5 % GAS-Risiko — kein Test oder Antibiotika

1~5–10 % — kein Test oder Antibiotika

2~11–17 % — optionaler Strep-Schnelltest

3~28–35 % — Strep-Schnelltest empfohlen

≥ 4~51–53 % — Strep-Schnelltest oder empirische Therapie

Disclaimer: Nur für Bildungszwecke. Kein Ersatz für klinische Beurteilung.

Wann verwenden

Use in patients presenting with sore throat to determine whether to test for GAS and/or initiate empiric antibiotics. Particularly useful in primary care and urgent care settings.

Klinische Hinweise

IDSA guidelines recommend AGAINST empiric antibiotics without testing (rapid strep or throat culture) in adults.
Score ≤ 1: GAS unlikely — neither testing nor antibiotics recommended.
Score 2–3: Test with rapid antigen detection; treat if positive.
Score ≥ 4: Empiric treatment reasonable while awaiting test results in some guidelines.
The McIsaac modification adds age as a criterion to improve specificity in adults (who have lower GAS prevalence).

References

Centor RM, et al. The diagnosis of strep throat in adults in the emergency room. Med Decis Making. 1981;1(3):239-246.
McIsaac WJ, et al. A clinical score to reduce unnecessary antibiotic use in patients with sore throat. CMAJ. 1998;158(1):75-83.

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Was ist der Centor-Score?

The Centor Score is a clinical prediction rule originally developed by Centor et al. in 1981 to estimate the probability of Group A Streptococcal (GAS) pharyngitis in patients presenting with sore throat. The original score used four criteria: tonsillar exudates, tender anterior cervical lymphadenopathy, fever, and absence of cough. In 1998, McIsaac modified the score by adding age as a fifth criterion, improving its accuracy across age groups. The Modified Centor (McIsaac) Score is now the standard version used in clinical practice.

Bewertung und Interpretation

The score ranges from −1 to 5. Age contributes +1 point for ages 3–14, 0 for ages 15–44, and −1 for age ≥ 45. Each clinical criterion (exudates, lymphadenopathy, fever, absence of cough) adds 1 point when present. The estimated probability of GAS pharyngitis increases with the score: ≤ 0 (~1–2.5%), 1 (~5–10%), 2 (~11–17%), 3 (~28–35%), and ≥ 4 (~51–53%). Management recommendations vary: scores ≤ 1 suggest no testing needed, scores 2–3 warrant rapid strep testing, and scores ≥ 4 may justify empiric treatment in some guidelines.

Leitlinienempfehlungen

The Infectious Diseases Society of America (IDSA) and the American Heart Association recommend against empiric antibiotic treatment for adults without confirmatory testing (rapid antigen or throat culture), regardless of Centor score. However, some international guidelines and the ACP/CDC "Choosing Wisely" approach allow for empiric treatment at high scores. In children (3–14 years), GAS prevalence is higher, and throat culture backup of negative rapid tests is recommended given the higher risk of rheumatic fever. The primary goal of GAS treatment is preventing rheumatic fever, suppurative complications, and reducing symptom duration.

🔑 Klinische Hinweise

Score ≤ 1 reliably excludes GAS in adults — avoid unnecessary antibiotics and testing.
IDSA guidelines recommend confirmatory testing even at high scores in adults before prescribing antibiotics.
In children, negative rapid strep should be backed up by throat culture — rapid tests have ~15% false-negative rate.
The absence of cough is a positive criterion — cough suggests viral etiology, making GAS less likely.

Wichtige Referenzen

Centor RM, et al. The diagnosis of strep throat in adults in the emergency room. Med Decis Making. 1981;1(3):239-246.
McIsaac WJ, et al. A clinical score to reduce unnecessary antibiotic use in patients with sore throat. CMAJ. 1998;158(1):75-83.
Shulman ST, et al. Clinical practice guideline for the diagnosis and management of group A streptococcal pharyngitis: 2012 update by IDSA. Clin Infect Dis. 2012;55(10):e86-e102.

Formel zuletzt überprüft: Februar 2026