Tonsillitis

Anatomy

Classification

Etiology

Viral (most common overall)

• Rhinovirus, adenovirus, parainfluenza, influenza A/B
• Epstein-Barr virus (EBV) - infectious mononucleosis
• Cytomegalovirus (CMV)
• Herpes simplex types 1 and 2
• Coxsackie A (herpangina)
• HIV (acute retroviral syndrome)

Bacterial

• Group A beta-hemolytic Streptococcus pyogenes (GABHS) - most common bacterial cause; also causes scarlet fever
• Non-group A beta-hemolytic streptococcus (groups B, C, G)
• Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus
• Mixed anaerobes (Vincent's angina)
• Neisseria gonorrhoeae
• Corynebacterium diphtheriae (grayish pseudomembrane)
• Mycoplasma pneumoniae, Chlamydia pneumoniae
• Treponema pallidum (secondary syphilis - punched-out ulcer appearance)
• Mycobacterium tuberculosis (in immunocompromised)

Fungal

• Candida spp.

Both bacteria and viruses play a part in acute inflammation. There is no evidence that viral tonsillitis is more or less severe than bacterial tonsillitis. In most cases, both tend to resolve quickly without treatment.

• Scott-Brown's Otorhinolaryngology Head & Neck Surgery, Vol 2

Clinical Features

• Short history of sore throat with fever
• Odynophagia (pain on swallowing)
• Referred otalgia (via Jacobson's nerve / Arnold's nerve)
• General malaise
• Examination: erythematous, swollen tonsils; occasional yellow-white pustules on tonsil crypts ("follicular tonsillitis")
• Tender jugulodigastric (tonsillar) lymph node enlargement
• In severe cases: trismus suggests peritonsillar abscess

Diagnosis

• Throat swab for culture and sensitivity (especially GABHS)
• EBV/Monospot test if infectious mononucleosis is suspected (sensitivity <50% in children, 70-90% in adults; confirm with specific antibody titres)
• FBC: leukocytosis in bacterial; atypical lymphocytes in EBV

Centor Criteria (for adults - predicts likelihood of GABHS)

1. Fever
2. Tonsillar exudate
3. Anterior cervical lymphadenopathy
4. Absence of cough

• 0-1: No treatment needed
• 2-3: GABHS testing warranted
• 4: Initiate antibiotic therapy

• Schwartz's Principles of Surgery, 11th Edition

Management

Acute Tonsillitis

• Adequate analgesia (paracetamol, NSAIDs)
• Hydration
• Saline gargles (soothing)
• Most cases resolve in a few days

• Not always needed immediately - if no improvement in 48-72 hours, start antibiotics
• If severe at onset, start early
• Benzyl-penicillin (Penicillin G) IV or Phenoxymethylpenicillin (Penicillin V) PO - drug of choice
• Amoxicillin/ampicillin: AVOID if infectious mononucleosis is suspected - causes a widespread rash in ~90% of EBV patients (30% with amoxicillin)
• In penicillin allergy: macrolide (e.g., erythromycin, clarithromycin)
• Cephalosporins are an alternative

• Oral or IM corticosteroids, in addition to antibiotics, expedite resolution of pain - especially in severe cases
• Short course beneficial in EBV tonsillitis with significant airway compromise

Recurrent Tonsillitis

• Individual episodes treated on their merits
• No benefit from long-term prophylactic antibiotics
• Consider surgical intervention (tonsillectomy) if criteria met

Complications of Acute Tonsillitis

Local

1. Peritonsillar abscess (Quinsy) - most common; pus collects between tonsil capsule and superior constrictor muscle
   • Features: severe unilateral sore throat, odynophagia, trismus, uvular deviation to opposite side
   • Treatment: IV high-dose penicillin or cephalosporin + needle aspiration or incision and drainage under local anaesthesia
2. Parapharyngeal abscess - may extend from peritonsillar space
3. Retropharyngeal abscess - especially in children
4. Septicaemia
5. Otitis media - via Eustachian tube spread
6. Airway obstruction - with massive tonsillar enlargement

Systemic / Non-infective (post-streptococcal)

• Rheumatic fever (Group A Strep tonsillitis - molecular mimicry - cardiac, joint, CNS involvement)
• Post-streptococcal glomerulonephritis (immune complex deposition in glomeruli)
• These late sequelae are the major importance of streptococcal sore throat - Robbins & Cotran Pathologic Basis of Disease

Other

• Tonsillitis and psoriasis: GABHS tonsillitis may exacerbate psoriasis via immune mechanisms; tonsillectomy occasionally advocated but evidence is weak

Infectious Mononucleosis (Glandular Fever) - Special Consideration

• Severe exudative tonsillitis + systemic upset
• Splenomegaly (risk of splenic rupture - avoid contact sports for 4-6 weeks)
• Deranged LFTs + haematological changes (atypical lymphocytes)
• In 30% of patients, secondary bacterial infection occurs on top
• Ampicillin/amoxicillin must be avoided (rash in 90% / 30%)
• Treat severe airway obstruction with corticosteroids
• Acyclovir: debatable; only for very severe cases

Tonsillectomy

Indications - Paradise / SIGN Criteria

• Sore throats are due to tonsillitis
• Episodes are disabling and prevent normal functioning
• Frequency threshold (any one of):
  • ≥7 episodes in the preceding year, OR
  • ≥5 episodes/year in each of the preceding 2 years, OR
  • ≥3 episodes/year in each of the preceding 3 years

Additional Indications (even if frequency not met)

• Multiple antibiotic allergies or intolerances
• History of peritonsillar abscess
• PFAPA syndrome (Periodic Fever, Aphthous stomatitis, Pharyngitis, Adenitis)
• Obstructive sleep apnea / sleep-disordered breathing with tonsillar hypertrophy
• Tonsillar asymmetry with concern for malignancy (biopsy may be needed)

Tonsillar Size Grading (for SDB assessment)

• Grade 1+: <25% of oropharyngeal width
• Grade 2+: 25-49%
• Grade 3+: 50-74%
• Grade 4+: ≥75% ("kissing tonsils")

Techniques

• Cold steel dissection - traditional standard
• Electrocautery / diathermy
• Laser tonsillectomy
• Radiofrequency ablation (coblation)
• No clear consensus on the best method; a 2025 meta-analysis (Mafra et al., Lasers Surg Med, PMID 40851448) compared laser vs. cold steel and found no definitive superiority

Post-operative Concerns

• Primary haemorrhage: within 24 hours
• Secondary haemorrhage: around day 5-10 (most common), due to sloughing of membrane
• Single intraoperative IV dexamethasone reduces post-op nausea and vomiting
• Tonsillectomy effective for sleep-disordered breathing in 60-70% of patients (but only 10-25% in obese children)

Key Points Summary

• Scott-Brown's Otorhinolaryngology Head & Neck Surgery, Vol 2
• Bailey and Love's Short Practice of Surgery, 28th Edition
• KJ Lee's Essential Otolaryngology
• Schwartz's Principles of Surgery, 11th Edition
• Robbins, Cotran & Kumar: Pathologic Basis of Disease
• The Harriet Lane Handbook, 23rd Edition