Criteria for Suspecting Bacterial Sore Throat in Adults
Use the modified Centor criteria to risk-stratify adults with sore throat, testing only those with 2 or more criteria, as patients with fewer than 2 criteria have viral pharyngitis and do not need testing or antibiotics. 1, 2
The Modified Centor Criteria (4-Point Score)
Apply these four clinical features to calculate the score:
- Fever by history (1 point) 1
- Tonsillar exudates (1 point) 1
- Tender anterior cervical adenopathy (1 point) 1
- Absence of cough (1 point) 1
Risk-Stratified Management Algorithm
Score 0-1 (Low probability):
- No testing needed 2
- Viral etiology most likely 2
- Symptomatic treatment only with ibuprofen or acetaminophen 1
Score 2 (Moderate probability):
- Consider rapid antigen detection test (RADT) or throat culture 2
- Do not prescribe antibiotics without positive test 1
Score 3-4 (High probability):
- Perform RADT or throat culture before prescribing antibiotics 1, 2
- Discuss modest benefits versus risks if test is positive 1
Clinical Features Strongly Suggesting Viral Pharyngitis
Do not test or treat with antibiotics when these features are present, as they indicate viral etiology:
- Cough 1
- Nasal congestion or coryza 1
- Conjunctivitis 1
- Hoarseness 1
- Diarrhea 1
- Oropharyngeal ulcers or vesicles 1
Red Flags Requiring Urgent Evaluation
Immediately evaluate for life-threatening conditions if the patient presents with:
- Difficulty swallowing or drooling (suggests peritonsillar abscess, parapharyngeal abscess, or epiglottitis) 1, 2
- Neck tenderness or swelling 1
- Severe unilateral throat pain with trismus and uvular deviation (peritonsillar abscess) 3, 2
- Persistent fever with neck pain in adolescents/young adults (consider Lemierre syndrome) 1, 3, 2
Critical Pitfalls to Avoid
Do not test patients with clear viral symptoms (cough, rhinorrhea, conjunctivitis), as this leads to false-positive results in asymptomatic Group A Streptococcus carriers and unnecessary antibiotic use. 2 Up to 10.9% of adults under 45 years carry Group A Streptococcus asymptomatically. 1, 3
Do not prescribe antibiotics based on clinical features alone without microbiological confirmation, as clinical features cannot reliably distinguish bacterial from viral pharyngitis. 4, 2
Do not use biomarkers (C-reactive protein, procalcitonin) routinely in assessment, as they are not necessary. 1, 2
Testing Approach When Indicated
The rapid antigen detection test (RADT) is the preferred initial test and does not require confirmatory throat culture after a negative result in adults. 2 Throat culture can be used as an alternative but is not necessary for routine diagnosis. 2