Can a patient with mononucleosis (mono) develop a white patch on their tonsils?

White Patches on Tonsils in Mononucleosis

Yes, patients with mononucleosis can develop white patches or exudates on their tonsils, though this is not the typical presentation and should prompt evaluation for bacterial superinfection, particularly Group A Streptococcus.

Clinical Presentation of Tonsillar Findings in Mono

Typical Appearance

• EBV-related oral lesions do not typically present with exudates, unlike bacterial pharyngitis 1
• The characteristic findings include erythema and diffuse injection of the oral and pharyngeal mucosae, tonsillopharyngeal erythema, marked tonsillar swelling and edema, and palatal petechiae 1, 2
• Periorbital and/or palpebral edema occurs in one-third of patients, which can help distinguish mono from bacterial pharyngitis 3

When White Patches Are Present

• If white patches or exudates are visible on the tonsils in a patient with suspected mono, this strongly suggests concurrent bacterial superinfection, most commonly Group A Streptococcus 1, 2
• Patients with infectious mononucleosis may be GAS carriers experiencing concurrent viral mononucleosis, making the clinical picture more complex 1
• The presence of tonsillopharyngeal exudates, tender anterior cervical lymph nodes, and absence of cough/rhinorrhea are features suggestive of bacterial origin 2

Diagnostic Approach When Exudates Are Present

Immediate Testing Required

• Perform rapid antigen detection test (RADT) for Group A Streptococcus when exudates are present 2
• If RADT is positive, this confirms concurrent streptococcal infection requiring antibiotic treatment 2
• If RADT is negative in children and adolescents, confirm with throat culture (gold standard) 2
• Obtain heterophile antibody test (monospot) or EBV-specific serology to confirm mononucleosis 3, 4

Laboratory Findings to Differentiate

• Peripheral blood showing lymphocytosis (≥50% of differential) with atypical lymphocytes (≥10% of total lymphocytes) supports mononucleosis 3, 4
• Bacterial pharyngitis typically shows neutrophilia with left shift, while viral pharyngitis shows relative lymphocytosis 2

Management When Both Conditions Coexist

Treatment Protocol

• If laboratory testing confirms both infectious mononucleosis and Group A Streptococcus, treat the streptococcal infection with antibiotics while managing mononucleosis supportively 1
• Avoid aminopenicillins (amoxicillin, ampicillin) as these cause a characteristic maculopapular rash in 80-100% of patients with active EBV infection 5, 2
• Use penicillin V or first-generation cephalosporins for confirmed GAS pharyngitis 2
• Treatment duration of 10 days is necessary for bacterial eradication 2

Supportive Care for Mono Component

• Provide topical analgesics such as benzydamine hydrochloride rinses for painful oral lesions 5, 1
• Use warm saline mouthwashes to cleanse the oral cavity 5, 1
• Systemic analgesics (ibuprofen or acetaminophen) for pain relief 5
• Adequate hydration and rest as tolerated 4

Critical Complications to Monitor

Severe Throat Swelling

• For grade 2-3 airway compromise, initiate methylprednisolone 1-2 mg/kg/day intravenously, with symptoms typically improving rapidly within hours 5
• Continue treatment until airway swelling resolves, then taper over 4-6 weeks for moderate cases 5

Peritonsillar Abscess Risk

• Patients with mononucleosis have a 23.4% risk of developing peritonsillar abscess, a significantly elevated rate compared to the general population 6
• Bilateral peritonsillar abscess can occur as a rare complication of acute EBV infection 7
• If no improvement occurs within 72 hours of appropriate therapy, consider surgical intervention including acute tonsillectomy 8

Common Pitfalls to Avoid

• Do not assume all exudates in mono are viral in origin—always test for bacterial superinfection 1, 2
• Never prescribe amoxicillin or ampicillin empirically for suspected streptococcal pharyngitis in adolescents or young adults without ruling out mono first 5, 2
• Do not rely solely on clinical appearance to differentiate bacterial from viral pharyngitis, as the signs and symptoms overlap too broadly 2
• Recognize that high erythrocyte sedimentation rate may indicate bacterial superinfection requiring antibiotic therapy 7