Symptoms of Acute Tonsillitis
Acute bacterial tonsillitis presents with sudden onset sore throat, fever (>38.3°C), tonsillar exudates, tender anterior cervical lymphadenopathy, and notably the absence of cough. 1, 2
Clinical Presentation
Bacterial Tonsillitis (Group A Streptococcus)
The hallmark features that distinguish bacterial from viral tonsillitis include:
- Sudden onset severe sore throat that worsens with swallowing 1, 3
- High fever (temperature >38.3°C) 1
- Tonsillar exudates - white or yellow patches on swollen, erythematous tonsils 1, 2
- Tender anterior cervical lymphadenopathy (>2 cm or tender lymph nodes) 1
- Absence of cough - this is a critical distinguishing feature 1
- Swollen tonsils with erythema and edema 1, 4
- Palatal petechiae in some cases 1
- Scarlatiniform rash occasionally present 1
Viral Tonsillitis
Viral presentations typically lack the severe features of bacterial infection:
- Sore throat without high fever 2
- Absence of tonsillar exudate 2
- Absence of significant cervical lymphadenopathy 2
- Associated symptoms suggesting viral etiology: cough, nasal congestion, conjunctivitis, hoarseness, diarrhea, or oropharyngeal ulcers/vesicles 1
Diagnostic Approach Using Clinical Scoring
Use the modified Centor criteria to determine the probability of bacterial infection before testing. 1 The criteria include:
- Fever by history (1 point)
- Tonsillar exudates (1 point)
- Tender anterior cervical adenopathy (1 point)
- Absence of cough (1 point)
Patients with fewer than 3 Centor criteria do not need testing and should not receive antibiotics. 1 Those with ≥3 criteria should undergo rapid antigen detection testing (RADT) and/or throat culture for Group A Streptococcus before initiating antibiotics. 1, 2, 5
Red Flag Symptoms Requiring Urgent Evaluation
Patients presenting with unusually severe symptoms require immediate evaluation for life-threatening complications:
- Difficulty swallowing or drooling 1, 2
- Neck tenderness or swelling 1, 2
- Severe pharyngitis in adolescents/young adults - consider Lemierre syndrome 1
- Persistent fever with rigors and night sweats 1
These symptoms may indicate peritonsillar abscess, parapharyngeal abscess, epiglottitis, or Lemierre syndrome, all requiring urgent diagnosis and treatment to prevent complications and death. 1, 2
Treatment Based on Confirmed Diagnosis
For Confirmed Group A Streptococcal Tonsillitis
Penicillin V for 10 days is the gold standard first-line treatment. 2, 5, 6 Amoxicillin is an acceptable alternative. 5, 6 The full 10-day course is mandatory to maximize bacterial eradication and prevent rheumatic fever and glomerulonephritis, even though symptoms may resolve earlier. 5, 6
For penicillin-allergic patients:
- Non-anaphylactic allergy: first-generation cephalosporins 2, 5
- Anaphylactic allergy: clindamycin, azithromycin, or clarithromycin 2, 5
For Viral Tonsillitis
Supportive care only with analgesics (aspirin, acetaminophen, NSAIDs, throat lozenges) for symptomatic relief. 1, 4, 3 Antibiotics provide no benefit and should not be prescribed. 1
Critical Pitfalls to Avoid
- Never initiate antibiotics without confirming Group A Streptococcus infection through testing - this leads to unnecessary antibiotic use in the majority of viral cases 2, 5
- Never prescribe antibiotic courses shorter than 10 days for confirmed bacterial tonsillitis - inadequate duration increases treatment failure risk and does not prevent rheumatic fever 2, 5, 6
- Do not use broad-spectrum antibiotics when narrow-spectrum penicillins are effective - this contributes to antibiotic resistance 5
- Do not perform routine follow-up throat cultures in asymptomatic patients who completed appropriate therapy - this may detect colonization rather than active infection 2, 5