What is the best management approach for a young adult diagnosed with infectious mononucleosis?

Management of Infectious Mononucleosis in Young Adults

Supportive care is the mainstay of treatment for infectious mononucleosis, including antipyretics for fever, adequate hydration, and rest as tolerated, with strict avoidance of contact sports for at least 8 weeks to prevent splenic rupture. 1, 2

Diagnostic Confirmation

• Heterophile antibody testing (Monospot) is the initial diagnostic test of choice, becoming positive between days 6-10 after symptom onset 1, 3
• False-negative results occur in approximately 10% of patients, particularly in children under 10 years and early in the infection course 3, 1
• When Monospot is negative but clinical suspicion remains high, order EBV-specific antibody testing: presence of VCA IgM without EBNA antibodies confirms recent primary infection 1, 3
• Expect peripheral blood lymphocytosis with at least 50% lymphocytes and >10% atypical lymphocytes 2, 4

Core Treatment Approach

Symptomatic Management

• Antipyretics (acetaminophen or NSAIDs) for fever control 1, 4
• Adequate hydration to maintain fluid balance 1, 4
• Activity modification based on patient's energy level—bed rest should not be enforced but guided by symptoms 4, 2
• Analgesics for pharyngitis and myalgias 4

Critical Activity Restrictions

• Mandatory avoidance of contact sports and strenuous exercise for 8 weeks from symptom onset or while splenomegaly persists 2, 4
• This restriction is non-negotiable given the 0.1-0.5% risk of spontaneous splenic rupture, which is potentially fatal 2, 5

What NOT to Do

• Do not routinely prescribe corticosteroids—they are not recommended for uncomplicated infectious mononucleosis 1, 4
• Do not prescribe acyclovir or other antivirals in immunocompetent patients—they provide no proven benefit 1, 6
• Do not prescribe antihistamines routinely 4

Exceptions Requiring Escalated Care

Corticosteroids ARE indicated for:

• Severe neurologic complications 1, 4
• Severe hematologic complications 1, 4
• Cardiac complications 1, 4
• Respiratory compromise or severe pharyngeal edema threatening airway 4

Antiviral Therapy May Be Considered:

• Only in immunocompromised patients with severe primary EBV infection, though evidence is limited 1
• Options include ganciclovir or foscarnet in this specific population 1

Special Populations: Immunocompromised Patients

• Reduce or discontinue immunomodulator therapy if possible when primary EBV infection is diagnosed 1
• Monitor for EBV-associated lymphoproliferative disease, which has increased risk in patients on immunosuppressive therapy 1
• Symptoms may be minimal in patients receiving corticosteroids, requiring higher clinical suspicion 1
• Consider measuring EBV viral load in peripheral blood using RT-PCR for early diagnosis when serologic results are inconclusive 6

Expected Clinical Course and Follow-Up

• Most symptoms resolve within 2-3 weeks, though fatigue may persist for up to 3 months 2, 4
• Infectious mononucleosis is a risk factor for chronic fatigue syndrome 2
• Patients typically have an uneventful recovery with appropriate activity restrictions 2

Common Pitfalls to Avoid

• Early testing pitfall: Heterophile antibodies may be negative in the first week of illness—repeat testing or use EBV-specific serology if clinical suspicion is high 1, 3
• Premature return to sports: Ensure full 8-week restriction is maintained regardless of symptom improvement to prevent splenic rupture 2, 4
• Unnecessary antibiotics: Do not prescribe ampicillin or amoxicillin, as they cause a characteristic rash in 80-100% of patients with infectious mononucleosis 4