Tonsillitis — A Comprehensive, Evidence-Based Report
1) Overview
What it is: Tonsillitis is inflammation of the palatine tonsils—lymphoid tissue on either side of the oropharynx—most often caused by viral infections and, less commonly, by bacteria such as Group A Streptococcus (GAS).
Body parts affected: Primarily the palatine tonsils and surrounding oropharyngeal mucosa; nearby structures (peritonsillar space, deep neck spaces) can be involved in complications.
How common / why it matters: In the U.S., tonsillitis accounts for ~0.4% of outpatient visits. GAS causes about 20–30% of sore throats in children and 5–15% in adults; most other cases are viral.
2) History & Discoveries
Ancient surgery: Cornelius Celsus (1st century AD) gave one of the earliest descriptions of tonsil removal; later, Galen and Paul of Aegina refined techniques.
Modern technique: By 1909, George Ernest Waugh popularized subcapsular blunt dissection, a foundation of today’s extracapsular tonsillectomy.
“Quinsy”: Historic term for peritonsillar abscess; the word traces to Greek kynanchē (“dog-choking”).
Guideline era: Contemporary indications for surgery are codified by AAO-HNS (2019 update) and echoed by AAFP/NICE-style criteria.
3) Symptoms
Early/common: Sore throat, dysphagia/odynophagia, fever, cervical lymphadenopathy, tonsillar erythema ± exudate; lack of cough favors GAS.
Advanced/worrying: Trismus, “hot-potato” voice, uvular deviation, drooling, severe unilateral pain—consider peritonsillar abscess; dehydration and airway compromise can occur. Scarlet fever rash may accompany GAS.
Progression: Viral cases peak and improve within ~3–7 days; bacterial cases may intensify without treatment and are the ones linked to suppurative (abscess) and non-suppurative (rheumatic fever, glomerulonephritis) complications.
4) Causes
Viral (majority): Adenovirus, rhinovirus, influenza, EBV, etc.
Bacterial: GAS (S. pyogenes) is the key pathogen; groups C/G streptococci and Fusobacterium necrophorum(notably in adolescents/young adults; associated with Lemierre’s syndrome) are additional causes.
Environmental/behavioral: Close-contact settings (schools, dorms), winter/early spring seasonality, and smoke exposure are associated with more throat infections.
Genetic/host factors (recurrent disease): Immunologic susceptibility has been described (e.g., HLA class II associations and aberrant responses to streptococcal superantigens) in recurrent tonsillitis.
5) Risk Factors
Age: School-aged children (5–15) have the highest GAS burden.
Exposure: Household/close-quarters transmission; seasonality (late winter/spring).
Lifestyle/Environment: Secondhand smoke exposure correlates with more tonsillitis and higher tonsillectomy rates in children.
Medical: History of recurrent pharyngitis/tonsillitis, or recent oropharyngeal infection (risk for Lemierre’s).
6) Complications
Suppurative: Peritonsillar abscess (PTA)—most common deep neck infection in young adults; ~30 per 100,000annually in the U.S. Can threaten the airway or spread to deep neck spaces.
Deep neck infections: Parapharyngeal/retropharyngeal abscess; internal jugular vein thrombosis (Lemierre’s syndrome) rarely follows fusobacterial tonsillitis.
Non-suppurative: Acute rheumatic fever and post-streptococcal glomerulonephritis—now uncommon where strep is promptly treated but still a global concern.
Functional: Pediatric obstructive sleep-disordered breathing/OSA from tonsillar hypertrophy; tonsillectomy is an established therapy in appropriate cases.
7) Diagnosis & Testing
Clinical scoring: Centor/McIsaac (North America) and FeverPAIN (UK) help estimate GAS probability and testing need, but don’t replace tests.
Microbiology:
RADT (rapid strep test): High specificity; variable sensitivity. In children, confirm a negative RADT with throat culture; in adults, culture back-up is usually unnecessary.
Throat culture: Gold standard when needed.
Imaging (for complications):
Ultrasound (intraoral or transcervical) is highly sensitive for ruling out PTA (≈89–91% sensitivity; moderate specificity).
CT with IV contrast is preferred when deep neck space infection is suspected or to map extent/complications.
8) Treatment Options
Supportive care (most cases): Analgesics (acetaminophen/NSAIDs), fluids, rest. Single-dose dexamethasone can modestly speed pain relief in severe sore throat (shared decision-making recommended).
Antibiotics (for confirmed/presumed GAS):
First-line: Penicillin V or amoxicillin for 10 days; alternatives for penicillin allergy include cephalexin (non-anaphylactic allergy), clindamycin, or azithromycin (consider local macrolide resistance).
Shorter regimens: A randomized trial found 5 days of high-dose penicillin V non-inferior to 10 days clinically (Sweden), but U.S. guidance still favors 10 days to optimize eradication and prevent sequelae; interpret locally.
Surgery (tonsillectomy):
Indications (children): Consider for recurrent infections meeting frequency thresholds (≥7 in 1 year, or ≥5/year for 2 years, or ≥3/year for 3 years, with documentation) or for obstructive sleep-disordered breathing. Watchful waiting is recommended below those thresholds.
Techniques: Extracapsular tonsillectomy is standard; intracapsular/partial (“tonsillotomy”) is used selectively (e.g., in some OSA cases) to reduce pain/bleeding at the cost of small regrowth risk.
9) Prevention & Precautionary Measures
Hygiene & exposure: Handwashing, respiratory etiquette, avoiding sharing utensils, and limiting close contact during acute illness. Children with confirmed strep should stay home until ≥24 hours after starting antibiotics and afebrile.
Environment: Reduce secondhand smoke exposure.
Vaccines: No licensed vaccine for GAS exists yet; multiple candidates are in clinical/preclinical stages.
10) Global & Regional Statistics
Etiology split: GAS accounts for ~20–30% of pediatric and 5–15% of adult sore throats.
PTA incidence: ~30 per 100,000 persons/year in the U.S.
Surgical activity: In the U.S., ~289,000 ambulatory tonsillectomies are performed annually in children <15 years. Rates vary widely across countries and health systems (OECD analyses show substantial international variation).
11) Recent Research & Future Prospects
Vaccines: Active global initiatives (e.g., SAVAC, WHO PDVAC) and mRNA/multivalent candidates are advancing; as of 2025, no approved vaccine.
Therapeutics: Continued evaluation of shorter antibiotic courses and antimicrobial-stewardship strategies to reduce resistance and pill burden.
Diagnostics: Broader use of ultrasound for PTA triage; optimizing when to culture vs RADT back-up, particularly in pediatrics.
12) Interesting Facts & Lesser-Known Insights
Not every sore throat needs antibiotics: Most tonsillitis is viral; test before treating when appropriate—especially in adults.
Tonsil stones (tonsilloliths) can follow recurrent tonsillitis and cause halitosis; they’re benign but bothersome and a rising reason for ENT visits in some cohorts.
Adolescents/young adults: If severe unilateral pain with neck swelling and fevers follows a sore throat, clinicians consider Lemierre’s syndrome—rare, but serious.
Key References
AAFP (2023): Tonsillitis & Tonsilloliths—diagnosis, causes, management.
CDC Clinical Guidance (2024–2025): Testing & treatment of GAS pharyngitis; school exclusion; RADT vs culture.
AAO-HNS (2019): Pediatric tonsillectomy guideline update (indications & peri-op care).
Peritonsillar Abscess: AAFP review and StatPearls—incidence, signs, imaging, and management.
Ultrasound for PTA: 2023 meta-analysis—test characteristics.
Short-course penicillin: BMJ RCT; AAFP summary.
GAS vaccines: CDC (no vaccine), WHO/SAVAC updates, recent mRNA candidate reports.
Historical context: Celsus and evolution of tonsillectomy techniques.
Practical takeaways
Most tonsillitis is viral: treat pain, not with antibiotics. Test when GAS is plausible; in children, back up negative RADT with culture.
Treat confirmed GAS to shorten illness, reduce transmission, and prevent sequelae; penicillin/amoxicillin remain first-line.
Escalate care quickly if red flags for PTA or deep neck infection appear.
For recurrent, debilitating episodes or OSA, tonsillectomy is evidence-based under defined criteria.