Centor score calculator

Centor/McIsaac Score

Modified Centor (McIsaac) Score

Criteria	No (0)	Yes (+1)
Tonsillar exudates or swelling	0	1
Tender/swollen anterior cervical lymph nodes	0	1
Temperature >38°C (100.4°F)	0	1
Absence of cough	0	1
Age modifier (McIsaac modification)
Age 3–14 years	0	1 (+1)
Age 15–44 years	(0 points — default)
Age ≥45 years	0	-1 (−1)
Modified Centor Score	0   / 5

Interpretation & Management
≤0	~1–2.5% strep probability — No testing or antibiotics needed.
1	~5–10% strep probability — No testing or antibiotics needed (optional rapid strep if high clinical suspicion).
2–3	~11–35% strep probability — Rapid strep testing recommended; treat if positive.
4–5	~51–53% strep probability — Consider empiric antibiotics or rapid strep test.

References
Centor RM et al. The diagnosis of strep throat in adults. Med Decis Making. 1981;1:239-246. PMID 6763125. McIsaac WJ et al. A clinical score to reduce unnecessary antibiotic use. CMAJ. 1998;158:75-83. PMID 9475915.