About This Page
This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.
The Bottom Line
- Usually viral — antibiotics rarely needed
- FeverPAIN 0–1/Centor 0–2: no antibiotic. FeverPAIN 2–3: delayed Rx. FeverPAIN 4–5/Centor 3–4: consider immediate
- First-line: phenoxymethylpenicillin 500 mg QDS for 5–10 days
- Do NOT give amoxicillin if EBV suspected — causes maculopapular rash
- Tonsillectomy: ≥7 episodes/year, ≥5/year x2 years, ≥3/year x3 years (Paradise criteria)
Overview
Acute tonsillitis is inflammation of the palatine tonsils. Viral causes predominate (adenovirus, EBV, rhinovirus). GAS is the most important bacterial pathogen (~15–30% in children, 5–10% adults). NICE recommends FeverPAIN or Centor criteria to guide antibiotic prescribing.
Epidemiology
Approximately 1.2 million GP consultations/year in the UK. Peak age 5–15 years. More common in winter. GAS carries small risk of peritonsillar abscess and (rarely in the UK) rheumatic fever.
Clinical Features
Symptoms
Severe sore throat — acute onset
Odynophagia
Fever, malaise, headache
Trismus — suspect peritonsillar abscess
Inability to swallow saliva — suspect epiglottitis or severe quinsy
Signs
Erythematous, swollen tonsils ± exudate
Tender anterior cervical lymph nodes
Absence of cough/coryza — bacterial more likely
Unilateral swelling with uvula deviation — quinsy
Splenomegaly + posterior LN — suspect EBV
Investigations
First-line
FeverPAIN/Centor scoringFeverPAIN: Fever, Purulence, Attend rapidly, Inflamed tonsils, No cough. Centor: exudate, nodes, fever, no cough
Second-line
MonospotIf EBV suspected — adolescent with prolonged sore throat, fatigue, splenomegaly
FBCAtypical lymphocytes in EBV
Specialist
ASOTRetrospective GAS confirmation if rheumatic fever or post-strep GN suspected
Management
NICE NG84 (Sore throat — acute), 20181
Self-care
- Paracetamol and/or ibuprofen
- Fluids, medicated lozenges
- Most resolve within 1 week
2
Antibiotic prescribing
- FeverPAIN 0–1/Centor 0–2: no antibiotic
- FeverPAIN 2–3: delayed/back-up prescription
- FeverPAIN 4–5/Centor 3–4: consider immediate if unwell
- First-line: phenoxymethylpenicillin 500 mg QDS 5–10 days
- Allergy: clarithromycin 250–500 mg BD 5 days
- AVOID amoxicillin if EBV suspected
3
Urgent referral
- Quinsy: needle aspiration + IV co-amoxiclav
- Lemierre syndrome: IV antibiotics, CT neck
4
Tonsillectomy
- Paradise criteria: ≥7/yr, ≥5/yr x2, ≥3/yr x3
- Also for recurrent quinsy or OSA from tonsillar hypertrophy
Complications
- Peritonsillar abscess (quinsy): Most common suppurative complication
- Parapharyngeal/retropharyngeal abscess
- Lemierre syndrome: Septic IJV thrombophlebitis — Fusobacterium
- Rheumatic fever: Rare in UK
- Post-streptococcal GN
UKMLA Exam Tips
- 1FeverPAIN/Centor commonly examined — know criteria and thresholds
- 2First-line: phenoxymethylpenicillin NOT amoxicillin. Amoxicillin + EBV = rash
- 3Quinsy: unilateral swelling + uvula deviation + trismus + hot potato voice
- 4Tonsillectomy: Paradise criteria
- 5Lemierre: young adult + sore throat → rigors + septic emboli → Fusobacterium
- 6EBV: adolescent + prolonged illness + splenomegaly + atypical lymphocytes → monospot
practicetest your knowledge on acute tonsillitisApply what you've learnt with UKMLA-style questions from the iatroX Q-Bank — ent and beyond.
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