Score

McIsaac score

A five-item clinical score estimating the likelihood that a sore throat is group A streptococcal, used to decide who to test, not to make the diagnosis.

Also called: modified Centor score

Total0

—Choose one option in each group

Absence of cough+1 point
Tender or swollen anterior cervical lymph nodes+1 point
Fever+1 point
Tonsillar exudate or swelling+1 point

Agechoose one

3 to 14 years+1 point
15 to 44 years0 points
45 years and over−1 point

Bands

−1 to 1: LowGroup A streptococcus unlikely; do not test or treat.
2 to 3: ModerateTest with a rapid antigen test and treat if positive; empirical treatment is an option at 3.
4 to 5: HighHigh probability; test and treat, with empirical treatment an option.

Educational use only. Guideline: McIsaac 1998 age modification; ACP/CDC management bands. Source: Fine AM, Nizet V, Mandl KD. Large-Scale Validation of the Centor and McIsaac Scores to Predict Group A Streptococcal Pharyngitis. Arch Intern Med. 2012. https://pmc.ncbi.nlm.nih.gov/articles/PMC3627733/; Centor Score (Modified/McIsaac) for Strep Pharyngitis, MDCalc, https://www.mdcalc.com/calc/104/centor-score-modified-mcisaac-strep-pharyngitis.