Tonsilitis

Overview

Tonsillitis is an acute inflammation of the palatine tonsils, which form part of Waldeyer’s mucosal-associated lymphoid ring at the entrance of the upper aerodigestive tract. It is one of the most common infectious presentations in pediatric and young adult populations, presenting as a spectrum from mild viral pharyngitis to severe bacterial infection with life-threatening airway or deep neck space complications.

While the majority of acute tonsillitis cases are viral and self-limiting, the primary clinical challenge is identifying bacterial infections—most notably Group A Beta-Hemolytic Streptococcus (GAS)—that warrant targeted antibiotic therapy to reduce symptom duration and prevent post-streptococcal non-suppurative complications such as Acute Rheumatic Fever.

Classification

Tonsillitis is classified based on clinical duration, recurrence, and histopathological pattern.

1. By Clinical Duration and Pattern

• Acute Tonsillitis: Sudden onset of symptoms lasting less than 2 weeks, resolving completely with appropriate supportive or antimicrobial care.
• Recurrent Tonsillitis: Multiple distinct acute episodes per year with complete resolution of symptoms between attacks.
• Chronic Tonsillitis: Persistent low-grade tonsillar inflammation lasting > 3 months, often accompanied by halitosis, persistent sore throat, and tonsilloliths (tonsil stones).

2. By Microbiological Etiology

• Viral Tonsillitis: Accounts for ~70–80% of cases overall; usually self-limiting.
• Bacterial Tonsillitis: Accounts for ~15–30% of cases; predominantly driven by Group A Beta-Hemolytic Streptococcus (Streptococcus pyogenes).

Aetiology & Risk Factors

Viral Aetiology (Most Common)

• Primary Pathogens: Rhinovirus, Adenovirus, Enterovirus, Coronavirus, Influenza, Parainfluenza, Respiratory Syncytial Virus (RSV).
• Epstein-Barr Virus (EBV): Primary agent of Infectious Mononucleosis; causes severe exudative tonsillitis in teenagers and young adults.
• Herpes Simplex Virus (HSV) & Coxsackievirus: Can cause ulcerative tonsillitis/herpangina.

Bacterial Aetiology

• Group A Beta-Hemolytic Streptococcus (GAS / Streptococcus pyogenes): Most significant bacterial cause (~15–30% of pediatric cases, 5–15% of adult cases).
• Non-GAS Streptococci: Group C and Group G Streptococci.
• Anaerobic & Other Bacteria: Fusobacterium necrophorum (key agent in young adults and Lemierre syndrome), Haemophilus influenzae, Moraxella catarrhalis, Mycoplasma pneumoniae, and Corynebacterium diphtheriae (rare).

Risk Factors

• Age: Peak incidence occurs between 5 and 15 years for bacterial tonsillitis; viral tonsillitis predominates in children < 5 years.
• Environmental Exposure: School attendance, day-care enrollment, overcrowded living environments, and winter/early spring seasonal variation.

Pathophysiology

1. Epithelial Invasion: Droplet inhalation or direct contact delivers pathogens to the non-keratinized stratified squamous epithelium lining the deep tonsillar crypts.
2. Immune Response Activation: Antigen-presenting cells trigger B- and T-cell proliferation within the lymphoid follicles of the palatine tonsils.
3. Exudate Formation: In bacterial infections, dense infiltration of neutrophils leads to localized tissue necrosis, cellular debris, and fibrin accumulation within crypts, manifesting clinically as white/yellow patchy tonsillar exudates.
4. Lymphatic Spread: Regional lymphatic drainage from the palatine tonsils leads to inflammation and tenderness of the jugulodigastric (tonsillar) lymph node, located at the angle of the mandible.

Clinical Manifestations

• Oropharyngeal Symptoms
  • Severe Sore Throat (Pharyngodynia): Rapid onset, worsening over 24–48 hours.
  • Odynophagia
  • Referred Otalgia: Ear pain on the affected side due to shared sensory innervation via the Glossopharyngeal nerve (Cranial Nerve IX).
  • Tonsillar Hypertrophy & Erythema
  • Tonsillar Exudates
  • Halitosis & Muffled Voice
• Systemic Symptoms
  • Fever & Chills
  • Malaise & Headache
  • Abdominal pain, nausea, and vomiting (common presentation in young children due to concurrent mesenteric adenitis).

• Cervical Lymphadenopathy
  • Tender Anterior Cervical Nodes

Clinical Feature	Viral Pharyngitis	Group A Streptococcus (GAS)	EBV / Mononucleosis
Onset & General	Gradual onset; mild systemic symptoms	Sudden onset; prominent fever	Insidious onset; severe fatigue & marked lethargy
Key Airway / ENT Symptoms	Cough, coryza, rhinorrhea, hoarseness	Absence of cough	Severe sore throat, odynophagia
Oropharyngeal Findings	Mild erythema; anterior oral stomatitis/ulcers	Discrete purulent exudates, palatal petechiae	Severe exudative pharyngitis, palatal petechiae
Lymphadenopathy	Mild, non-tender, or generalized	Tender anterior cervical nodes	Prominent posterior cervical nodes
Associated Physical Findings	Conjunctivitis	Scarlatiniform rash (Scarlet Fever)	Hepatosplenomegaly

Diagnosis

Clinical Scoring Systems (Centor / McIsaac Score)

Assigns 1 point for each of the following:

• Fever > 38.0°C (100.4°F).
• Tonsillar exudates.
• Tender anterior cervical lymphadenopathy.
• Absence of cough.
• (McIsaac modification: Age 3–14 years +1 point; Age >= 45 years -1 point).

Management based on score:

• Score 0–1: Low risk (< 10% GAS); no antibiotics or testing required.
• Score 2–3: Moderate risk; perform Rapid Antigen Detection Test (RADT) or throat swab culture.
• Score >= 4: High risk (~30–50% GAS); empiric antibiotics or testing recommended.

Microbiological Testing

• Rapid Antigen Detection Test (RADT): High specificity (> 95%), variable sensitivity (70–90%). Provides results within minutes.
• Throat Swab Culture (Gold Standard): Swab both tonsillar pillars and the posterior pharyngeal wall (avoid touching tongue or cheeks). Confirms GAS and provides antibiotic sensitivities.

Adjunctive Laboratory Investigations

• Monospot Test / EBV Serology
• Complete Blood Count (FBC)

Treatment

Management combines supportive care for symptom relief, targeted antibiotics for bacterial etiology, and surgical evaluation for recurrent disease.

Supportive Management (First-Line for ALL Patients)

• Analgesia & Antipyretics: Regular Paracetamol (Acetaminophen) and/or Ibuprofen for pain and fever control.
• Hydration: Encouraging cool fluids, ice pops, or oral rehydration solutions to prevent dehydration.
• Local Measures: Warm salt water gargles or topical anesthetic lozenges/sprays (e.g., Benzydamine).

Antibiotic Therapy (For Confirmed or High-Probability GAS)

• First-Line Regimen: Phenoxymethylpenicillin (Penicillin V) oral for 10 full days (10-day duration is mandatory to achieve complete eradication of GAS and prevent Acute Rheumatic Fever).

Surgical Management (Paradise Criteria for Elective Tonsillectomy)

Consider referral for tonsillectomy if documented recurrent frequency meets ANY of the following:

• >= 7 episodes in the preceding year.
• >= 5 episodes per year for 2 consecutive years.
• >= 3 episodes per year for 3 consecutive years.
• And each episode must be documented with features such as fever > 38°C, exudate, positive GAS test, or cervical adenitis.

Other Indications: Peritonsillar abscess history (recurrent or unresponsive), obstructive sleep apnea (OSA) due to severe adenotonsillar hypertrophy, or suspected malignancy (asymmetric tonsillar enlargement).

Complications & Prognosis

Suppurative (Local / Regional) Complications

• Peritonsillar Abscess (Quinsy)
• Retropharyngeal / Parapharyngeal Abscess
• Lemierre Syndrome
• Acute Otitis Media & Acute Rhinosinusitis

Non-Suppurative (Post-Streptococcal) Complications

• Acute Rheumatic Fever (ARF)
• Post-Streptococcal Glomerulonephritis (PSGN)
• Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS)
• Scarlet Fever

Prognosis

• Most cases of acute tonsillitis resolve within 5–7 days without sequelae.
• Antibiotics reduce symptom duration by approximately 16–24 hours and significantly decrease the risk of quinsy and Acute Rheumatic Fever.

References

1. Windfuhr JP, Toepfner N, Steffen G, Waldfahrer F, Berner R. Clinical practice guideline: tonsillitis I. Diagnostics and nonsurgical management. Eur Arch Otorhinolaryngol. 2016;273(4):973-987. doi:10.1007/s00405-015-3872-6
2. Baugh RF, Archer SM, Mitchell RB, et al. Clinical practice guideline: tonsillectomy in children. Otolaryngol Head Neck Surg. 2011;144(1 Suppl):S1-S30. doi:10.1177/0194599810389949
3. Spinks A, Glasziou PP, Del Mar CB. Antibiotics for sore throat. Cochrane Database Syst Rev. 2021;12(12):CD000023. doi:10.1002/14651858.CD000023.pub5