What are the typical presentation, complications, and management of primary Epstein‑Barr virus infection (infectious mononucleosis) in an 11‑year‑old child?

Features of EBV Infection in an 11-Year-Old Child

In an 11-year-old child, primary EBV infection typically presents with the classic triad of fever, tonsillar pharyngitis, and cervical lymphadenopathy, with most cases resolving spontaneously over weeks to months, though approximately 20% develop complications requiring close monitoring. 1

Clinical Presentation

Cardinal Features

• Fever is nearly universal (present in >95% of cases), with mean duration of 10 days 1
• Tonsillar pharyngitis with exudative tonsillitis occurs in over half of patients 1
• Cervical lymphadenopathy is present in the majority of cases, typically bilateral and tender 1, 2
• Profound fatigue is characteristic and may persist for up to 3 months, though most resolve within weeks 2

Additional Common Manifestations

• Hepatosplenomegaly occurs in approximately 50% (spleen) and 10% (liver) of cases 2
• Periorbital or palpebral edema, typically bilateral, develops in one-third of patients 2
• Skin rash (erythematous, maculopapular, widely scattered) occurs in 10-45% of cases 2
• Upper respiratory symptoms including cough and rhinorrhea are present in over half of patients 1

Critical Caveat: Amoxicillin-Associated Rash

• Avoid amoxicillin in suspected EBV infection as it causes severe rash in patients with active EBV infection 3
• This is particularly important in the 11-year age group where amoxicillin might otherwise be considered for pharyngitis

Laboratory Findings

Hematologic Abnormalities

• Peripheral blood leukocytosis with lymphocytes comprising ≥50% of the white blood cell differential 4, 2
• Atypical lymphocytosis ≥10% of total lymphocyte count (mean 12%) 4, 1
• Some patients may present with white blood cell count ≤10,000/mm³, which is a risk factor for complications 1

Hepatic Involvement

• Elevated transaminases are the most striking laboratory finding, occurring in approximately 90% of cases 4
• Mean AST levels of 167 IU/L and ALT levels of 221 IU/L 1
• AST ≥150 IU/L is a significant risk factor for developing complications 1

Diagnostic Approach

Initial Testing in an 11-Year-Old

• Heterophile antibody test (Monospot) is the first-line diagnostic test with 87% sensitivity and 91% specificity 4
• The test typically becomes positive between days 6-10 after symptom onset 4
• Important limitation: False-negative rate of approximately 10% overall, with higher rates in children younger than 10 years and during the first week of illness 4

When to Proceed to EBV-Specific Serology

If clinical suspicion remains high despite negative heterophile test, obtain EBV serology including: 4

• IgM to viral capsid antigen (VCA)
• IgG to VCA
• Antibodies to Epstein-Barr nuclear antigen (EBNA)

Acute primary infection is confirmed by presence of VCA IgM (with or without VCA IgG) and absence of EBNA antibodies 4

Differential Diagnosis to Consider

When heterophile test is negative, consider: 4

• Cytomegalovirus (CMV) infection
• HIV infection (particularly important in adolescents)
• Toxoplasma gondii infection
• Adenovirus infection
• Streptococcal pharyngitis (may coexist with EBV)

Complications (Occur in ~20% of Cases)

Categories of Complications 1

• Hematologic: Anemia, thrombocytopenia
• Hepatobiliary: Severe hepatitis, cholestasis
• Central nervous system: Encephalitis, meningitis, Guillain-Barré syndrome
• Obstructive airway problems: Upper airway obstruction from tonsillar hypertrophy

Risk Factors for Complications 1

• Female gender
• Absence of tonsillopharyngitis (paradoxically indicates higher risk)
• White blood cell count ≤10,000/mm³
• AST ≥150 IU/L

Life-Threatening Complication

• Splenic rupture occurs in 0.1-0.5% of cases and is potentially fatal 4, 2
• This is the most feared complication requiring activity restriction

Management

Supportive Care

• Treatment is primarily supportive with no role for antiviral agents (acyclovir, ganciclovir) in immunocompetent patients 4, 5
• Reduction of activity and bed rest as tolerated 2

Activity Restrictions

• Avoid contact sports and strenuous exercise for 8 weeks or while splenomegaly persists to reduce risk of splenic rupture 4, 2
• This restriction is critical given the 0.1-0.5% risk of spontaneous splenic rupture

Role of Corticosteroids

• Reserve corticosteroids for specific complications only, particularly upper airway obstruction and possibly immune-mediated anemia or thrombocytopenia 4, 5
• Should not be used routinely in uncomplicated cases 4

Monitoring Patients at Higher Risk

Patients with risk factors (female, no tonsillopharyngitis, WBC ≤10,000/mm³, AST ≥150 IU/L) require closer monitoring for development of complications, which significantly prolong hospitalization 1

Prognosis

• Most patients recover uneventfully within weeks to months 1, 2
• All patients in the Taiwanese pediatric cohort recovered under supportive management 1
• Infectious mononucleosis is a risk factor for chronic fatigue syndrome in a minority of cases 2