Tonsillitis

Antimicrobial prescribing: NHS Lothian
NHS Lothian

Most cases are viral, and 90% of cases resolve without treatment in 7 days.

Use the Centor score to decide if antibiotics are needed.

Centor Score

Not valid in children <3 years of age

Centor Score, 1 point each for:

  • Tonsillar exudate
  • Tender anterior cervical lymphadenopathy or lymphadenitis
  • History of fever (>38°C)
  • No cough

Interpretation: 

Centor Score

0, 1, or 2

Do not offer antimicrobials

3 or 4

Immediate antimicrobials

Required Investigations

  • Send a throat swab for bacterial culture in patients who are being prescribed antibiotics.
  • Consider infectious mononucleosis if notable cervical lymphadenopathy: send an EBV IgM test to virology and/or request monospot from haematology.
  • Send a HIV test if glandular fever is part of the diagnosis.
  • Take a sexual history and send an STI screen.

Antimicrobial Recommendation

Recommended total duration: 5 days

  Nonsevere

Severe (requiring hospital admission or signs of sepsis)
Antimicrobial recommendation Phenoxymethylpenicillin 500mg every 6 hours orally Benzylpenicillin 1.2g every 4 hours IV
Penicillin-allergy

Clarithromycin 500mg every 12 hours orally

OR

Erythromycin 500mg every 6 hours orally if pregnant

 Vancomycin (use NHS Lothian Calculator located AMT intranet page) choose trough 10-15 mg/L
  • Do not use amoxicillin as it may cause a rash in those with infectious mononucleosis.

Notes

Likely organisms:

  • Most tonsillitis/sore throats are viral.
  • Group A Streptococci (Strep. pyogenes).
  • Occasionally Group C/G Streptococci.
  • Severe symptoms and signs of sepsis consider Fusobacterium necrophorum (Lemierre syndrome).
  • In patients without vaccination, and older adults who have travelled to areas where diphtheria is more common consider risk assessment and discuss with microbiology regarding diphtheria (Corynebacterium diphtheriae).