Sore throat - acute
Exam Tips
- In OSCEs, first rule out airway threat and sepsis before focusing on antibiotic decisions.
- Use FeverPAIN or Centor explicitly and justify immediate vs delayed vs no antibiotic prescribing.
- Cough/coryza strongly supports viral illness; absence of cough with fever, exudate, and tender anterior cervical nodes supports streptococcal probability.
- Always assess hydration in children (including wet nappy history) and document safety-net advice.
- Sore throat in patients on carbimazole/DMARDs/chemotherapy is a neutropenia red flag: urgent FBC and specialist escalation.
- Red flags for deep neck infection include trismus, muffled voice, unilateral swelling, neck pain/swelling, and systemic toxicity.
Definition
Acute sore throat is a short-duration inflammatory syndrome of the pharyngeal and/or tonsillar mucosa, usually caused by an upper respiratory tract infection. In clinical practice it includes acute pharyngitis and tonsillitis, presents with odynophagia and throat pain, and is most often self-limiting within 1-2 weeks.
Pathophysiology
Most cases are viral (for example rhinovirus, coronavirus, parainfluenza, influenza, adenovirus), causing epithelial infection of the oropharynx with local cytokine release (IL-1, IL-6, TNF) that produces pain, erythema, fever, and malaise. Bacterial disease is less common; Group A beta-haemolytic streptococcus (Streptococcus pyogenes) adheres to pharyngeal epithelium (including via M-protein-associated virulence mechanisms), causing exudative tonsillopharyngitis and occasionally toxin-mediated scarlet fever. Suppurative spread can track into peritonsillar/deep neck spaces (quinsy, parapharyngeal or retropharyngeal infection), while rare post-streptococcal immune phenomena include rheumatic fever and glomerulonephritis. Fusobacterium necrophorum can rarely cause septic thrombophlebitis of the internal jugular vein (Lemierre syndrome). For anatomy revision, review a deep-neck-space diagram in your ENT atlas.
Risk Factors
- School age (especially 5-15 years) and close-contact settings
- Winter/early spring seasonality for streptococcal disease
- Recent viral upper respiratory infection exposure
- Immunosuppression or immunocompromise (chemotherapy, transplant immunosuppressants, HIV, haematological disease)
- Smoking or other mucosal irritants
- Drug-related neutropenia/agranulocytosis risk (for example carbimazole, clozapine, sulfasalazine, cytotoxics)
- Recurrent tonsillitis history
Clinical Features
Symptoms
- Sore throat with painful swallowing (odynophagia)
- Fever and malaise
- Headache
- Nausea, vomiting, or abdominal pain (especially in children)
- Reduced oral intake or reduced urine output suggesting dehydration
- Cough/coryza/rhinorrhoea (more suggestive of viral cause)
- Myalgia and fatigue (consider influenza)
- Prolonged severe fatigue with persistent pharyngitis (consider glandular fever)
Signs
- Pharyngeal erythema with or without exudate
- Tonsillar enlargement, erythema, and tonsillar exudate
- Tender anterior cervical lymphadenopathy
- Temperature often above 38 degrees C (often above 38.5 degrees C in streptococcal infection)
- Absence of cough supports streptococcal probability scores
- Scarlatiniform rash in toxin-producing streptococcal infection
- Conjunctivitis with fever suggests adenoviral pharyngoconjunctival fever
- Trismus, muffled 'hot-potato' voice, uvular deviation, unilateral swelling suggest peritonsillar abscess
Investigations
Management
Lifestyle Modifications
- Explain natural history: usually self-limiting; many improve by day 3 and most by 1 week
- Encourage oral hydration; safety-net for reduced intake/urine output
- Advise rest and simple supportive care (warm/cool fluids as tolerated)
- Provide clear red-flag advice: breathing difficulty, drooling, severe unilateral throat pain/swelling, trismus, worsening systemic illness, dehydration, or sepsis features
Pharmacological Treatment
Analgesia/antipyretics
- Paracetamol 1 g orally every 4-6 hours (max 4 g/day) in adults
- Ibuprofen 200-400 mg orally three times daily with food if needed (adult OTC range)
- Child doses should be weight/age-adjusted per BNF for Children
Use the lowest effective dose for the shortest time. Avoid aspirin in under 16s (Reye syndrome risk). Use NSAIDs cautiously or avoid in renal impairment, active peptic ulcer disease, NSAID-sensitive asthma, anticoagulation, or significant dehydration.
First-line antibiotic when indicated (high score/systemically unwell/high-risk)
- Phenoxymethylpenicillin 500 mg orally four times daily for 5 days (adult)
Consider immediate or delayed prescription based on FeverPAIN/Centor and clinical risk. Confirm no penicillin allergy. Benefits are modest in average cases (symptom reduction typically limited), so discuss adverse effects and antimicrobial stewardship.
Penicillin allergy alternatives
- Clarithromycin 250 mg to 500 mg orally twice daily for 5 days (adult)
- Erythromycin (preferred macrolide in pregnancy when needed): 250 mg to 500 mg four times daily, or 500 mg to 1 g twice daily for 5 days (adult)
Check interactions (for example statins, anticoagulants) and QT-prolongation risk before macrolides. Warn about gastrointestinal adverse effects.
High-risk medication contexts requiring urgent blood checks/specialist input
- If on carbimazole: withhold immediately and obtain urgent FBC if sore throat/fever
- If on DMARD with concerning sore throat: hold drug, urgent FBC, discuss with rheumatology
- If on chemotherapy/transplant immunosuppression or with severe immunocompromise: urgent specialist referral
These scenarios carry risk of neutropenic sepsis or severe infection; manage as potentially serious even if throat findings seem mild.
Surgical / Interventional
- Needle aspiration or incision and drainage for peritonsillar abscess (quinsy), with ENT input
- Urgent airway management in threatened airway (for example suspected epiglottitis managed where immediate intubation is available)
- Drainage of deep neck space abscesses where indicated
- Interval tonsillectomy may be considered for recurrent tonsillitis under ENT criteria (not routine for a single acute episode)
Complications
- Otitis media
- Acute sinusitis
- Peritonsillar abscess (quinsy) with potential airway compromise
- Parapharyngeal or retropharyngeal abscess
- Scarlet fever (toxin-mediated rash with streptococcal infection)
- Acute rheumatic fever (rare in UK)
- Post-streptococcal glomerulonephritis (rare)
- Reactive arthritis
- Lemierre syndrome (rare; internal jugular septic thrombophlebitis)
Prognosis
Overall prognosis is good: acute viral or bacterial sore throat is usually self-limiting and resolves within 2 weeks. Around 40% improve by 3 days and most are better by 1 week. Infectious mononucleosis throat symptoms often settle within 1-2 weeks, but fatigue may persist for weeks to months.
Sources & References
💊BNF Drug References(1)
- Phenoxymethylpenicillin[management.pharmacological]
✅NICE Guidelines(1)
- Sore throat - acute[overview]