Infectious Disease

Modified Centor (McIsaac) Score

The Modified Centor score (McIsaac 1998) estimates the probability of group A streptococcal (GAS) pharyngitis. Four criteria (fever > 38°C, absence of cough, tonsillar exudates, tender anterior cervical adenopathy) score 1 point each, with an age adjustment (3–14 years +1, 15–44 years 0, ≥ 45 years −1); the total is clamped to 0–4. Scores of 0–1 suggest low, 2–3 intermediate, and 4 high GAS probability, guiding rapid antigen testing and treatment decisions.