II. Indications
- Evaluation for Group A Streptococcal Pharyngitis
III. Criteria: Modified Centor (recommended)
IV. Approach: Clinical Suspicion based on scoring above
- Strep Score 4 to 5 (or Strep Score 2 if patient unreliable)
- Treat with antibiotics
- Strep Score 2 to 3: Perform rapid Antigen test
- Antigen test positive: Treat with antibiotics
- Antigen test negative: Throat Culture
- Strep Score 0 to 1
V. Criteria: Older, original criteria with derivation (1 point for each clinical finding)
- Original Criteria (interpretation below based on these)
- Reference
- Centor (1990) in Sox (1990) Common Diagnostic, p.247
- Modifiers (Not included in interpretation below)
- McIsaac Decision Rule modifier
- Age younger than 15 years: +1 point
- Age 15 to 45 years: 0 points
- Age over 45 years: -1 points
- McIsaac (2000) CMAJ 163:811-5 [PubMed]
- Exposure to known Pharyngitis contact
- Added with Walsh Clinical Prediction Rules
- McGinn (2003) Mayo Clin Proc 78:289-93 [PubMed]
- McIsaac Decision Rule modifier
VI. Interpretation (Clinic and ER probability based on original criteria)
- Based on original criteria above
- Score 0: Streptococcus probability 1% (3% in ER)
- Score 1: Streptococcus probability 4% (8% in ER)
- Score 2: Streptococcus probability 9% (18% in ER)
- Score 3: Streptococcus probability 21% (38% in ER)
- Score 4: Streptococcus probability 43% (63% in ER)
VII. References
- Centor (1990) in Sox (1990) Common Diagnostic, p.247
- Sloane (1998) Family Medicine, p. 629