Introduction
Tonsillitis refers to inflammation of the palatine tonsils, most commonly due to infection.
Whilst most cases of tonsillitis are mild infective episodes and fully resolve with conservative measures or antibiotics, there are significant complications including deep neck space infections and potential airway compromise.
Tonsillitis is a common presentation in primary care, most common in children and young adults. Recurrent tonsillitis has an incidence in the UK of around 100 per 1000 population a year.
In this article, we shall look at the pathophysiology, clinical features and management of tonsillitis.
Pathophysiology
The palatine tonsils are located within the oropharynx as part of Waldeyer’s ring (Fig. 1). Waldeyer’s ring is a collection of lymphatic tissue located within the pharynx, forming a ringed arrangement, comprised of the pharyngeal tonsils (adenoids), tubal tonsils (x2), palatine tonsils (x2), and lingual tonsil.
Tonsillitis is most caused by viral infections (50-80% of cases), including adenovirus, rhinovirus, influenza, and parainfluenza, or secondary to glandular fever, caused by Epstein-Barr virus (EBV). Bacterial causes account for approximately one third of cases (causative organisms include Streptococcus pyogenes, S. Aureus, and M. Catarrhalis).
Figure 1 – The four tonsils that comprise Waldeyer’s ring
Clinical Features
Tonsillitis presents with odynophagia or dysphagia, often with associated pyrexia, halitosis, or a “hot potato voice”. A cough or coryzal symptoms may also be present.
On examination, the tonsils will appear erythematous and swollen (Fig. 2). When examining a patient with suspected tonsillitis, ensure to undertake an A to E assessment, as the airway can be at risk of compromise if the tonsils are significantly enlarged.
Figure 2 – A patient with tonsillitis, demonstrating erythematous & swollen tonsils with white exudate
A purulent exudate* may be present (more common in bacterial cases), as well as anterior cervical lymphadenopathy, more prominently around the jugulodigastric nodes.
Patient can present with trismus, where there is limited opening of the mouth – this is due to inflammation and painful spasm of the muscles of mastication. Any neck stiffness may suggest a deep neck space infection.
*Patients with glandular fever often have very large, inflamed tonsils covered with white exudates, and prominent palpable cervical lymphadenopathy
The Centor Criteria
The Centor criteria are often used in primary care to assess for the likelihood of bacterial infection in tonsillitis
Antibiotics should be considered if ≥2 criteria are met:
- History of pyrexia
- Tonsillar exudates
- No cough
- Tender anterior cervical lymphadenopathy
The Centor criteria however is not suitable for emergency presentations and is rarely used in a hospital setting.
The size of the tonsils can be graded according to Brodsky grading scale (Table 1); consider a peritonsillar abscess (quinsy, see below) in cases of peritonsillar swelling with deviation of the uvula.
| Grade |
Definition |
| Grade 0 | Tonsils in fossa |
| Grade 1 | Tonsils outside of fossa and occupy ≤25% of the oropharyngeal width |
| Grade 2 | Tonsils occupy 26-50% of the oropharyngeal width |
| Grade 3 | Tonsils occupy 51-75% of the oropharyngeal width |
| Grade 4 | Tonsils occupy > 75% of the oropharyngeal width |
Table 1 – The Brodsky Grading Scale for Tonsil Size
Differential Diagnosis
Important differentials to consider include head and neck malignancy, haematological malignancies, or deep space neck abscess, especially in chronic cases.
Investigation
Tonsillitis is often a clinical diagnosis; further investigations are only warranted in cases with suspected complications (see below). If the patient has hoarse voice/stridor, a flexible nasoendoscope is indicated to evaluate for any associated supraglottitis.
For those who have presented to hospital, patients should have routine bloods (FBC, U&Es, CRPs, LFTs, and clotting) performed. Glandular fever should be checked with monospot test for EBV
Consider a CT neck scan with intravenous contrast if a deep neck space infection is suspected, or if there are signs of parapharyngeal swelling during flexible nasoendoscopy.
Figure 3 – A patient with severe purulent tonsillitis
Management
Ensuring sufficient analgesia (normally achieved with Difflam spray and regular paracetamol ±NSAIDs) and hydration is the mainstay of treatment.
Hospital admission may be required in uncomplicated cases who cannot swallow fluids after initial management. If the cause is thought to be bacterial, antibiotics should be prescribed* (typically penicillin-based, however follow local guidelines).
Additionally, patients with glandular fever need to be advised not to participate in contact sports for 6 weeks, due to risk of splenic injury (as transient splenomegaly can occur in some cases).
*Remember that starting amoxicillin in tonsillitis caused by EBV can result in a maculopapular rash developing.
Tonsillectomy
The definitive management for patients with recurrent tonsillitis is with surgical tonsillectomy.
Typical indications for surgical excision of the tonsils include:
- ≥7 episodes in the preceding year, or ≥5 episodes in each of preceding 2 years, or ≥3 episodes in each of preceding 3 years
- Suspected malignancy or the presence of sleep apnoea
- Two previous peritonsillar abscesses
The main complication from tonsillectomy is secondary bleeding (>24hrs post-op) from infection to the tonsillar bed, occurring in around 5% of cases and most at days 5-9 post-operatively.
This can be treated medically with antibiotics and hydrogen peroxide mouth wash, however around 1% of patients will require surgical intervention for secondary haemorrhage post-tonsillectomy.
Figure 4 – Patient post-operative day 7 following tonsillectomy
Complications
Peritonsillar Abscess
A quinsy is a peritonsillar abscess, which can occur as a sequelae of acute bacterial tonsillitis. Patients will typically present with a severe sore throat (worse unilaterally), pyrexia, and severe odynophagia. Associated symptoms include stertor and trismus, often presenting in similar ways in children.
Examination can be difficult in cases with trismus), however there will often be extensive erythema and soft palate swelling, with the anterior arch being pushed medially and a deviated uvula (Fig. 5).
Patients should be admitted and started on intravenous antibiotics, with regular analgesia and topical analgesic throat sprays. All peritonsillar abscess will require either needle aspiration (using topical local anaesthetic) or an incision and drainage (with further opening via use of Tilley’s forceps).
Figure 5 – A quinsy, causing significant uvula deviation
Key Points
- Tonsillitis refers to inflammation of the palatine tonsils, most cases of which will resolve with conservative management
- The Centor criteria is often used in primary care to assess for the likelihood of bacterial infection
- Peritonsillar abscess and deep space neck infections are rare complications of tonsillitis that should be assessed for in any prolonged, severe, or atypical case
