Overview

A sore throat describes an acute upper respiratory tract infection. It is an umbrella term for pharyngitis and tonsillitis. An acute sore throat is usually caused by viral or bacterial infection.

Causes

Infectious causes

  • Rhinovirus, coronavirus, influenza, parainfluenza viruses
  • Streptococcus pyogenes is the most common bacterial cause
  • Haemophilus influenzae type B (Hib) – rarer due to Hib vaccination and can cause epiglottitis
  • Candida albicans – seen in HIV/immunodeficiency and corticosteroid inhaler use

Non-infectious causes

Epidemiology

  • Sore throat is very common
  • Incidence is higher in children and young adults
  • Bacterial sore throat is more common in winter/early spring

Differential Diagnoses

Epiglottitis

  • Rapid onset of symptoms
  • Usually seen in children, particularly if they have not had the Hib vaccine
  • Stridor and difficulty breathing present
  • Drooling present
  • The patient looks very unwell and may lean forward (tripod position)

Peritonsillar abscess (quinsy)

  • The patient’s voice is muffled – “hot potato voice”
  • Trismus present (lockjaw)
  • Uvula displaced
  • Enlarged and displaced tonsils present
  • Peritonsillar swelling

Infectious mononucleosis

Diphtheria

  • A “diphtheric membrane” is seen – a grey-green membrane in the oropharynx
  • The patient may not have had the diphtheria vaccination
  • There may be profound cervical lymphadenopathy

Investigations

  • Diagnosis is clinical – no investigations are routinely performed
    • If there is suspected immunodeficiency/bone marrow suppression: urgent FBC
      • Example scenarios are:
        • Patients taking DMARDs/carbimazole or patients on chemotherapy

Management

All stable patients

  • If Centor criteria 3 or 4: antibiotics, options are:
    • 1st-line: 7/10 days phenoxymethylpenicillin (penicillin V)
      • If penicillin-allergic: clarithromycin
  • If Centor criteria <3: analgesia and safety-netting advice

Centor Criteria

The Centor criteria can assess the probability of the sore throat being due to a bacterial infection. Each criterion scores 1 point. If the score is 3 or 4, prescribe antibiotics. The four criteria can be remembered using CENT:

  • No Cough
  • Tonsillar Exudate
  • Cervical lymphadeNopathy (swollen Nodes)
  • Temperature >38.5°C

Monitoring

  • Patients are not routinely followed up unless:
    • Symptoms have not improved after 3-4 days – consider an alternate diagnosis
    • Difficulty swallowing and breathing arises
    • >7 episodes in a year – refer to ENT and consider tonsillectomy

Patient Advice

  • Patients should be educated on the nature of sore throat and how antibiotics may not be needed
  • Patients should ensure they have adequate fluid intake and take paracetamol as an antipyretic and ibuprofen for analgesia
  • Patients can try saltwater gargling and over-the-counter lozenges for symptom relief
  • Patients should avoid hot drinks as they can worsen pain
  • Children can return to school after the fever has improved and they feel well enough to or 24 hours after starting antibiotics

Complications

  • Otitis media
  • Peritonsillar abscess – quinsy
  • Rheumatic fever
  • Post-tonsillectomy haemorrhage:
    • All patients should be assessed by ENT
    • If within first 6-8 hours of surgery: immediately return to theatre
    • If between 5-10 days after surgery: admit and antibiotics, consider surgery
  • Scarlet fever – due to erythrogenic toxins from Streptococcus pyogenes

Prognosis

  • Sore throat is usually self-limiting and resolves within 2 weeks

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