🦠 McIsaac Score (Modified Centor, Pharyngitis)
UseGuide rational testing and antibiotic use in sore throat.
SourceMcIsaac WJ, et al. CMAJ 1998
This-shift next steps
After scoring: open the scene pack, peer scores, and the matching pathway. Local reference — no HIS write.
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Methodology · worked example, guidelines & full notes
Adds age adjustment to Centor criteria.
When to use
Guide rational testing and antibiotic use in sore throat.
How it works
Temp > 38, no cough, tender anterior nodes, tonsillar swelling/exudate each +1; age 3–14 +1, 15–44 0, ≥ 45 −1.
Key points
- Adds age adjustment to Centor criteria.
- Most scores warrant confirmatory RADT/culture, not empiric antibiotics.
- Reduces unnecessary antibiotic prescribing.
References
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Temperature > 38°C | No |
|---|---|
| Absence of cough | Cough present (0) |
| Tender anterior cervical nodes | No |
| Tonsillar swelling/exudate | No |
| Age | 15–44 (0) |
→McIsaac0
- Strep probability：~1–2.5% — no testing/antibiotics
- Note：Most guidelines recommend confirming with RADT/culture rather than empiric antibiotics, except possibly at the highest scores.
| Temperature > 38°C | No |
|---|---|
| Absence of cough | Cough present (0) |
| Tender anterior cervical nodes | No |
| Tonsillar swelling/exudate | No |
| Age | 3–14 (+1) |
→McIsaac1
- Strep probability：~5–10%
- Note：Most guidelines recommend confirming with RADT/culture rather than empiric antibiotics, except possibly at the highest scores.
Verification & sources · governance
FAQ
Frequently asked questions
- What are the limits and cautions when using McIsaac Score (Modified Centor, Pharyngitis)?
- For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
- Does McIsaac Score (Modified Centor, Pharyngitis) upload patient data? Where is it calculated?
- Calculation runs locally in the browser; inputs and results are not uploaded. For licensed clinicians only; interpret with history, investigations and local protocols — not a diagnosis or prescription.
- How is McIsaac Score (Modified Centor, Pharyngitis) calculated in practice? Can you show a worked example?
- Inputs: Temperature > 38°C No, Absence of cough Cough present (0), Tender anterior cervical nodes No, Tonsillar swelling/exudate No, Age 15–44 (0) → Result: McIsaac 0（Strep probability: ~1–2.5% — no testing/antibiotics, Note: Most guidelines recommend confirming with RADT/culture rather than empiric antibiotics, except possibly at the highest scores.） Inputs: Temperature > 38°C No, Absence of cough Cough present (0), Tender anterior cervical nodes No, Tonsillar swelling/exudate No, Age 3–14 (+1) → Result: McIsaac 1（Strep probability: ~5–10%, Note: Most guidelines recommend confirming with RADT/culture rather than empiric antibiotics, except possibly at the highest scores.）