What are the differential diagnoses and recommended management for white exudates on the tonsils?

White Spots on Tonsils: Differential Diagnosis and Management

Immediate Clinical Assessment

White exudates on the tonsils do not reliably distinguish bacterial from viral causes and require microbiological confirmation before prescribing antibiotics. 1, 2

The presence of white patches, exudates, or tonsillar inflammation occurs in both viral and bacterial infections, making clinical appearance alone insufficient for diagnosis 3. Even experienced clinicians cannot differentiate these etiologies based solely on physical examination 1.

Differential Diagnosis

Viral Causes (70-95% of cases)

• Adenovirus, rhinovirus, coronavirus, respiratory syncytial virus – most common viral pathogens causing exudative tonsillitis 4, 5
• Epstein-Barr virus (infectious mononucleosis) – presents with white exudates, generalized lymphadenopathy (especially posterior cervical nodes), and marked tonsillar enlargement 2, 3
• Enteroviruses, coxsackievirus, herpes simplex virus – can produce tonsillar inflammation with exudates 5, 6

Bacterial Causes (5-30% of cases, age-dependent)

• Group A β-hemolytic Streptococcus (Streptococcus pyogenes) – accounts for 15-30% of cases in children aged 5-15 years and 5-15% in adults 1, 4
• Groups C and G streptococci – less common bacterial causes that can produce similar appearance 1, 3
• Arcanobacterium haemolyticum – causes pharyngitis with scarlatiniform rash in adolescents/young adults 3
• Fusobacterium necrophorum – associated with Lemmiere syndrome and necrotizing tonsillitis 6, 7

Clinical Features That Guide Testing

Features Favoring Viral Etiology (DO NOT TEST for GAS)

• Cough, rhinorrhea, hoarseness, or conjunctivitis – strongly suggest viral cause 1, 2
• Discrete oral ulcers or ulcerative stomatitis – characteristic of viral infection 1, 2
• Diarrhea – more common with viral pharyngitis 3
• Gradual onset with constitutional symptoms 3

Features Favoring Group A Streptococcal Infection (PERFORM TESTING)

• Sudden onset of severe sore throat with fever ≥101°F (38.3°C) 1, 8
• Tonsillopharyngeal erythema with or without patchy exudates 1, 8
• Tender, enlarged anterior cervical lymph nodes 1, 8
• Palatal petechiae ("doughnut lesions") – highly specific finding 8
• Absence of viral upper respiratory symptoms (no cough, rhinorrhea, hoarseness, conjunctivitis) 1, 2
• Age 5-15 years – highest risk group 1, 4
• Winter/early spring presentation or known GAS exposure 1, 3

Diagnostic Algorithm

Step 1: Clinical Assessment

If viral features present (cough, rhinorrhea, hoarseness, conjunctivitis, oral ulcers):

• Do NOT perform GAS testing 1, 2
• Provide symptomatic care only 2

If viral features absent AND bacterial features present:

• Proceed to Step 2 for microbiological testing 1

Step 2: Microbiological Testing (Age-Specific)

Children and Adolescents (≤18 years):

1. Perform rapid antigen detection test (RADT) first 1
2. If RADT positive: Treat immediately (specificity ≥95%) 1
3. If RADT negative: Obtain backup throat culture (RADT sensitivity only 80-90%, missing 10-20% of infections) 1
4. Initiate antibiotics if culture returns positive (treatment within 9 days still prevents rheumatic fever) 1, 2

Adults (>18 years):

1. Perform RADT 1, 2
2. If RADT positive: Treat immediately 1, 2
3. If RADT negative: No backup culture needed (GAS prevalence only 5-10%, virtually zero rheumatic fever risk) 1, 2

Step 3: Consider Infectious Mononucleosis

If generalized lymphadenopathy (especially posterior cervical nodes) present:

• Obtain heterophile antibody test (Monospot) and complete blood count with differential 2, 3
• Lymphocyte-to-WBC ratio >0.35 has 100% specificity and 90% sensitivity for glandular fever 9
• Do NOT prescribe amoxicillin/ampicillin – causes maculopapular rash in 30-100% of EBV patients 2, 3

Treatment Recommendations

Confirmed Group A Streptococcal Pharyngitis

First-Line Therapy (10-day course mandatory):

• Penicillin V: 250 mg 2-3 times daily (<27 kg) or 500 mg 2-3 times daily (≥27 kg and adults) 1, 2
• Amoxicillin: 50 mg/kg once daily (maximum 1 g) or 25 mg/kg twice daily (maximum 500 mg per dose) 1, 2
• Benzathine penicillin G (IM): Single dose of 600,000 U (<27 kg) or 1.2 million U (≥27 kg and adults) – for adherence concerns 1, 2

Penicillin-Allergic Patients:

• Non-anaphylactic allergy: First-generation cephalosporin (cephalexin 500 mg twice daily or cefadroxil 1 g once daily) for 10 days 1, 2, 3
• Anaphylactic/immediate hypersensitivity:
  • Clindamycin: 300 mg three times daily (adults) or 20 mg/kg/day divided three times daily (children, max 1.8 g/day) for 10 days – preferred alternative (≈1% GAS resistance) 1, 2, 3
  • Azithromycin: 500 mg once daily (adults) or 12 mg/kg once daily (children, max 500 mg) for 5 days 1, 2
  • Clarithromycin: 250 mg twice daily (adults) or 15 mg/kg/day divided twice daily (children) for 10 days 1, 2
  • Note: Macrolide resistance 5-8% in U.S.; clindamycin preferred when beta-lactams contraindicated 2, 3

Complete the full 10-day course (except azithromycin 5 days) to ensure bacterial eradication and prevent acute rheumatic fever 1, 2

Viral Pharyngitis or Negative GAS Testing

Withhold all antibiotics and provide symptomatic care only 1, 2:

• Ibuprofen 400-600 mg every 6-8 hours or acetaminophen 650-1000 mg every 6 hours for pain/fever 2
• Avoid aspirin in children (Reye syndrome risk) 2, 3
• Adequate hydration, warm saline gargles, throat lozenges 1, 2
• Reassure that symptoms typically resolve within 3-7 days without antibiotics 2

Corticosteroids are NOT recommended for routine viral pharyngitis 2

Infectious Mononucleosis

• Supportive care only – analgesics, hydration, rest 2, 3
• Avoid amoxicillin/ampicillin – causes severe maculopapular rash in 30-100% of EBV patients 2, 3
• Monitor for splenic enlargement; avoid contact sports for 3-4 weeks 3

Critical Pitfalls to Avoid

• Do NOT prescribe antibiotics based solely on white exudates or tonsillar appearance – identical findings occur in viral infections 1, 2, 3
• Do NOT test patients with obvious viral features (cough, rhinorrhea, conjunctivitis) – yields false-positives from asymptomatic GAS carriers (10-15% prevalence) 1, 2
• Do NOT omit backup throat culture after negative RADT in children – misses 10-20% of true GAS infections, increasing rheumatic fever risk 1
• Do NOT order backup throat culture after negative RADT in adults – wastes resources without clinical benefit 1, 2
• Do NOT test or treat asymptomatic household contacts – up to one-third are carriers; prophylaxis does not reduce infection rates 1, 2
• Do NOT perform routine follow-up testing after completing therapy in asymptomatic patients – positive results often reflect carrier state, not treatment failure 1, 2
• Do NOT use broad-spectrum cephalosporins (cefdinir, cefpodoxime) when narrow-spectrum agents appropriate – increases cost and resistance 2, 3

When to Reassess or Refer

• Development of high fever, severe dysphagia, drooling, or respiratory distress – consider peritonsillar abscess, retropharyngeal abscess, or epiglottitis 7
• Petechial rash involving palms/soles with fever – consider Rocky Mountain Spotted Fever or meningococcemia; requires immediate empiric therapy 2, 3
• Symptoms persisting >3-4 days or worsening despite appropriate therapy – consider suppurative complications or alternative diagnoses 2, 7
• Recurrent episodes meeting Paradise criteria – consider tonsillectomy (≥7 episodes in past year, ≥5 episodes/year for 2 years, or ≥3 episodes/year for 3 years with proper documentation) 1