Introduction
Epidemiology
- Incidence: 500.00 cases per 100,000 person-years
- Peak incidence: 6-15 years
- Sex ratio: 1:1
Condition | Relative incidence |
---|---|
Viral upper respiratory tract infections | 60.00 |
Acute tonsillitis | 1 |
Peritonsillar abscess (quinsy) | 0.06 |
Acute epiglottitis | 0.004 |
<1 | 1-5 | 6+ | 16+ | 30+ | 40+ | 50+ | 60+ | 70+ | 80+ |
Aetiology
- Viral
- Tonsillitis is usually viral.
- Rhinovirus, coronavirus and parainfluenza virus (ordered from most to least common) account for 25% of all sore throats
- Adenovirus (4%)
- Influenza virus type A and B (4%)
- Herpes simplex virus (2%)
- Epstein-Barr virus (glandular fever; 1%).
- Bacterial
- Group A ß–haemolytic streptococci (20% in children; 10% in adults)
- Group C ß–haemolytic streptococci (5%)
- Rarer bacterial causes: Mycoplasma pneumonia and Neisseria gonorrhoea.
Pathophysiology
- Micro-organisms which successfully penetrate the tonsillar epithelium are phagocytosed by macrophages.
- Macrophages then process and present them to B and T cells within the tonsils, thus stimulating cellular and humoral immune responses.
- Inflammatory cytokines (e.g. phospholipase A2) are produced.
- Such local inflammatory pathways destroy the virus or bacteria, cause pyrexia and result in oropharyngeal swelling, pain and erythema.
Clinical features
- Sore throat (99%)
- Fever >38ºC (82%)
- Dysphagia (66%)
- Nasal congestion, headache, earache, cough (47%)
- These 4 symptoms may be present if viral aetiology.
- If no cough is present, this is more likely bacterial cause.
Examination of the pharynx may reveal:
- Severely inflamed tonsils (87%)
- Painfully enlarged anterior cervical lymph nodes (49%)
- Purulent tonsils (41%)
- Pus on the tonsils is suggestive of bacterial cause.
Do not examine if epiglottitis suspected.
- Additional features suggestive of epiglottitis:
- A young child
- A muffled voice
- Excessive drooling and pooling of saliva.
- Call for an anaesthetist and an ENT surgeon.
Investigations
- Investigations are only used if confirmation of group A streptococcal (GAS) infection is required (e.g. in patients on immunosuppression, very old or young, with severe symptoms).
- In these patients, the NICE 2018 Clinical Knowledge Summary suggests performing a rapid antigen test for GAS.
- If this antigen test is negative, a throat culture should be performed.
In all other patients, clinical examination in combination with a clinical prediction score (FeverPAIN or Centor - see 'Management' section) should be used to establish the likelihood of GAS infection.
- This is important, as GAS aetiology requires antibiotic treatment.
Differential diagnosis
- Viral upper respiratory tract infection
- Similarities: sore throat, fever.
- Differences: coryza, nasal obstruction, facial pain, earache.
- Primary herpes labialis (oral herpes)
- Similarities: sore throat, fever cervical lymphadenopathy.
- Differences: mouth pain, burning or tingling, visible vesicles or crusted ulcer.
- Peritonsillar abscess (quinsy)
- Can be a complication of tonsillitis.
- Similarities: sore throat, high fever, dysphagia.
- Differences: trismus (lockjaw), muffled voice, uvular deviation, unilateral enlarged and displaced tonsil.
- Infectious mononucleosis
- Similarities: sore throat, fever, lymphadenopathy.
- Differences: does not resolve after 1 week, splenomegaly, hepatomegaly, persistent fatigue, weight loss.
- Epiglottitis
- An airway emergency. Can be life-threatening due to airway obstruction.
- Now rare since Haemophilus influenza type B is vaccinated against in routine childhood immunisations.
- Similarities: sore throat, high fever.
- Differences: muffled voice, excessive drooling (in children), possible stridor and breathing difficulty.
- Retropharyngeal abscess
- Collection of pus in the space between the pre-vertebral fascia and the neck constrictor muscles.
- Can be life-threatening if not identified early.
- Similarities: sore throat, high fever, dysphagia.
- Differences: trismus (lockjaw), visible neck swelling, torticollis.
- Gonococcal pharyngitis
- Similarities: sore throat, high fever, dysphagia.
- Differences: adolescent and adult patients with history of oral sex (sexually transmitted).
- Primary HIV infection
- Similarities: sore throat, high fever, lymphadenopathy.
- Differences: more generalised lymphadenopathy, weight loss, fatigue, malaise, risk factors for HIV.
Management
- Reassure – symptoms can last for around 1 week, but most people get better within this time without treatment.
- Paracetamol or ibuprofen – for pain or fever.
- Fluids – adequate intake maintained.
Other treatment
- antibiotics are not routinely indicated, but may be indicated if certain criteria are met as below
- if antibiotics are indicated then either phenoxymethylpenicillin or erythromycin (if the patient is penicillin allergic) should be given. Either a 7 or 10 day course should be given
- there is some evidence that a single dose of oral corticosteroid may reduce the severity and duration of pain, although this has not yet been incorporated into UK guidelines
NICE indications for antibiotics
- features of marked systemic upset secondary to the acute sore throat
- unilateral peritonsillitis
- a history of rheumatic fever
- an increased risk from acute infection (such as a child with diabetes mellitus or immunodeficiency)
- patients with acute sore throat/acute pharyngitis/acute tonsillitis when 3 or more Centor criteria are present
Scoring systems
The Centor criteria are: score 1 point for each (maximum score of 4)
- presence of tonsillar exudate
- tender anterior cervical lymphadenopathy or lymphadenitis
- history of fever
- absence of cough
Centor score | Likelihood of isolating Streptococci |
---|---|
0 or 1 or 2 | 3 to 17% |
3 or 4 | 32 to 56% |
The FeverPAIN criteria are: score 1 point for each (maximum score of 5)
- Fever over 38°C.
- Purulence (pharyngeal/tonsillar exudate).
- Attend rapidly (3 days or less)
- Severely Inflamed tonsils
- No cough or coryza
FeverPAIN score | Likelihood of isolating Streptococci |
---|---|
0 or 1 | 13 to 18% |
2 or 3 | 34% to 40% |
4 or 5 | 62% to 65% |
Special patient groups:
- If on DMARDs or carbimazole, check FBC urgently.
- If immunosuppressed (eg leukaemia, HIV/AIDS), seek urgent specialist advice.
Complications
Potential complications include:
- Acute otitis media
- Common, benign and self-limiting.
- Antibiotics reduce the risk.
- Peritonsillar abscess (quinsy) or neck abscess
- Usually in the first 2 months after acute tonsillitis episode.
- Presents with spiking fever, neck pain and dysphagia.
- Antibiotics reduce the risk. Drainage required.
- Acute sinusitis
- In 0.4% of untreated patients.
- Antibiotics reduce the risk.
- Scarlet fever
- Presents as a blanching erythematous papular rash, a strawberry tongue and circumoral pallor.
- Acute rheumatic fever
- Extremely rare (<1:100,000).
- Causes widespread inflammation throughout the body.
- Presents with arthritis, subcutaneous nodules, erythema marginatum, chorea and carditis.
- Antibiotics reduce the risk.
- Acute post-streptococcal glomerulonephritis:
- Exceedingly rare.
- Presents with haematuria, oedema, vomiting and anorexia.
- Streptococcal toxic shock syndrome:
- Very rare but life-threatening.
- Presents with progressive multiple organ failure and shock.
- Due to exaggerated inflammatory response to streptococcal antigens.