What is the diagnosis and treatment for a patient with fever, bilateral whitish pus on tonsils, and anterior and posterior cervical lymphadenopathy, considering acute follicular tonsillitis vs infectious mononucleosis?

Diagnosis and Management of Acute Tonsillitis with Fever, Tonsillar Exudate, and Cervical Lymphadenopathy

This presentation strongly suggests bacterial pharyngotonsillitis (acute follicular tonsillitis) caused by Group A Streptococcus, and you should confirm with rapid antigen detection testing (RADT) or throat culture before initiating antibiotic therapy with penicillin V or amoxicillin for 10 days. 1, 2, 3

Diagnostic Approach

Clinical Features Favoring Bacterial (GAS) Tonsillitis

Your patient's presentation is highly consistent with Group A β-hemolytic streptococcal pharyngitis based on:

• Sudden onset fever (typically >38°C) 1, 2
• Bilateral tonsillar exudates (whitish pus) 1, 3
• Tender anterior AND posterior cervical lymphadenopathy 1, 2

The presence of both anterior and posterior cervical lymphadenopathy is particularly important - while GAS typically causes anterior cervical lymphadenopathy, the posterior chain involvement raises consideration for infectious mononucleosis (IM). 1

Key Distinguishing Features

Features that would suggest viral etiology (including IM) rather than GAS: 1, 2

• Cough, coryza, or conjunctivitis
• Hoarseness
• Diarrhea
• Discrete oral ulcerations
• Viral exanthem

Specific features suggesting infectious mononucleosis: 4

• Posterior cervical lymphadenopathy (more prominent than anterior)
• Splenomegaly or hepatomegaly
• Generalized lymphadenopathy
• Severe fatigue disproportionate to fever
• Palatal petechiae

Mandatory Testing Before Treatment

You must perform microbiologic confirmation before initiating antibiotics - clinical diagnosis alone has insufficient accuracy (≤80% predictive value even with scoring systems). 1, 2, 5

Testing options: 1, 2

• Rapid antigen detection test (RADT) - results within minutes, 90-95% sensitivity
• Throat culture on blood agar - gold standard, 90-95% sensitivity, but requires 24-48 hours
• If RADT is negative but clinical suspicion remains high, follow with throat culture 1

For suspected infectious mononucleosis: 4

• Monospot or heterophile antibody test
• Complete blood count (looking for atypical lymphocytosis)
• EBV-specific serology if heterophile antibody negative

Treatment Algorithm

If GAS Confirmed (Positive RADT or Culture)

First-line treatment: 2, 3, 5

• Penicillin V: 250 mg orally 2-3 times daily for 10 days (children: 250 mg 2-3 times daily)
• Alternative: Amoxicillin: 500 mg twice daily for 10 days (better compliance due to twice-daily dosing) 2, 5

The full 10-day course is mandatory - shorter courses have significantly lower bacterial eradication rates and fail to prevent rheumatic fever. 2, 3, 5

For penicillin-allergic patients: 2, 5

• Non-anaphylactic allergy: First-generation cephalosporins (cephalexin, cefadroxil) for 10 days
• Anaphylactic allergy: Clindamycin, azithromycin, or clarithromycin 2, 6

If Infectious Mononucleosis Confirmed

Critical warning: DO NOT prescribe amoxicillin or ampicillin for infectious mononucleosis - approximately 90% of IM patients develop a characteristic maculopapular rash when exposed to aminopenicillins. 7

Treatment is supportive: 8, 9

• Analgesia (NSAIDs or acetaminophen)
• Hydration
• Rest
• Avoid contact sports for 3-4 weeks (risk of splenic rupture)

Corticosteroids may be considered for: 9

• Severe tonsillar hypertrophy with impending upper airway obstruction
• Massive splenomegaly
• Severe thrombocytopenia or hemolytic anemia

Acute tonsillectomy is reserved for: 9

• Severe upper airway obstruction not responding to corticosteroids
• This is rare and requires ENT consultation

Critical Pitfalls to Avoid

Never initiate antibiotics without microbiologic confirmation - over 50% of acute pharyngitis cases are viral, and empiric treatment leads to unnecessary antibiotic exposure, adverse effects, and resistance. 1, 5

Never prescribe antibiotic courses shorter than 10 days for confirmed GAS - 5-day courses have inadequate bacterial eradication rates and increased risk of rheumatic fever. 2, 3

Never use broad-spectrum antibiotics when narrow-spectrum penicillins are effective - this contributes to antimicrobial resistance without improving outcomes. 2, 5

Never perform routine follow-up throat cultures in asymptomatic patients who completed appropriate therapy - this is not recommended and may detect chronic carriers rather than treatment failures. 1, 2, 3

Watch for severe complications requiring urgent evaluation: 3

• Difficulty swallowing with drooling (peritonsillar or parapharyngeal abscess)
• Severe neck swelling or tenderness
• Respiratory distress (upper airway obstruction)
• Trismus (inability to open mouth)

When to Reconsider the Diagnosis

If symptoms persist or worsen despite appropriate antibiotic therapy: 2

• Verify medication compliance
• Consider peritonsillar abscess or other suppurative complications
• Consider that patient may be a chronic GAS carrier with intercurrent viral infection
• Consider alternative pathogens or infectious mononucleosis

The presence of posterior cervical lymphadenopathy in your patient warrants specific attention to rule out IM, as this is less typical for isolated GAS pharyngitis. 1, 4