Bacterial Tonsillitis

Bacterial tonsillitis is acute or chronic bacterial infection of the palatine tonsils, caused by group A streptococci in most cases, and by group C and G streptococci, Fusobacterium necrophorum, Haemophilus influenzae, Staphylococcus aureus, anaerobes, Corynebacterium diphtheriae and Neisseria gonorrhoeae in some. Polymicrobial infection is common in chronic and recurrent disease.

• Occurs at any age, with a peak in school children and young adults.
• Risk of diphtheria exists where immunisation coverage is incomplete.

Sore throat, fever, dysphagia, halitosis, tonsillar enlargement with pus or exudate, tender cervical nodes, muffled voice, otalgia, malaise.

• Chronic tonsillitis: persistent sore throat, tonsilloliths, halitosis, enlarged tender nodes; recurrent acute episodes.
• Diphtheria: grey adherent membrane that bleeds on removal, bull neck, toxaemia, myocarditis.
• Differential diagnosis: viral tonsillitis, infectious mononucleosis, diphtheria, peritonsillar abscess, tonsillar lymphoma or carcinoma, leukaemia, agranulocytosis, tonsillar candidiasis, herpangina, Vincent angina, syphilis, tuberculosis of the tonsil, acute HIV infection.
• Complications: peritonsillar and parapharyngeal abscess, Lemierre syndrome (septic thrombophlebitis of the internal jugular vein), airway obstruction, rheumatic fever, glomerulonephritis, otitis media, sinusitis, sleep disordered breathing, diphtheria myocarditis and neuropathy.

Clinical, with throat swab culture.

• Rapid antigen detection test for group A streptococci; throat swab for bacterial culture and sensitivity (for persistent or recurrent cases); culture for C. diphtheriae on Loeffler or tellurite medium if membrane is present.
• Full blood count, CRP, monospot test, HIV test, blood cultures in sepsis.
• Ultrasound or CT neck with contrast for abscess or Lemierre syndrome.

Antibiotics for confirmed or likely bacterial disease and drainage of any collection.

• Supportive: rest, oral fluids, saline gargles, soft diet, humidified air, analgesia, isolation until 24 hours after starting antibiotics (and isolation of diphtheria until cultures are negative), adequate hydration with IV fluids if unable to swallow.
• Pharmacological: phenoxymethylpenicillin 500 mg twice daily (or 250 mg four times daily) for 10 days (children 250 mg two to three times daily); benzathine benzylpenicillin 1.2 million units IM single dose (600,000 units for children under 27 kg). Severe or complicated disease: benzylpenicillin 1.2 to 2.4 g IV every 6 hours plus metronidazole 500 mg IV every 8 hours, switching to oral amoxicillin clavulanate 625 mg three times daily to complete 10 to 14 days. Recurrent or chronic tonsillitis: amoxicillin clavulanate 625 mg three times daily for 7 to 10 days, or clindamycin 300 mg three times daily. Penicillin allergy: azithromycin 500 mg day 1 then 250 mg daily for 4 days, or clindamycin. Diphtheria: diphtheria antitoxin 20,000 to 100,000 units IV (by severity) after test dose, plus benzylpenicillin 50,000 units/kg/day or erythromycin 500 mg four times daily for 14 days. Analgesia: paracetamol 1 g every 6 hours, ibuprofen 400 mg every 8 hours.
• Procedures: drainage of peritonsillar abscess by needle aspiration or incision; tonsillectomy for recurrent infection (7 episodes in one year, 5 per year for two years, 3 per year for three years), chronic tonsillitis with tonsilloliths unresponsive to treatment, or suspected malignancy; secure the airway in obstruction.
• Special groups: pregnancy, penicillin or cefalexin; children, weight based dosing and a check of diphtheria immunisation; HIV, coinfection testing and treatment; immunocompromised, culture before antibiotics.
• Red flags: stridor, drooling, trismus, bull neck, grey membrane, unilateral tonsillar mass, neck swelling or pain with fever and rigors, persistent fever beyond 48 hours, bleeding.
• Follow-up: review at 48 to 72 hours; ENT referral for recurrent or chronic cases; diphtheria contacts need prophylaxis with benzathine benzylpenicillin 1.2 million units IM single dose or erythromycin 500 mg four times daily for 7 to 10 days and immunisation.