Management of Mononucleosis with Splenomegaly
Patients with infectious mononucleosis and splenomegaly must strictly avoid contact sports and strenuous physical activity for a minimum of 8 weeks or until splenomegaly resolves, as splenic rupture is the most feared and potentially fatal complication, occurring in 0.1-0.5% of cases. 1, 2
Activity Restriction
- Mandatory restriction from contact sports and strenuous exercise for 8 weeks minimum or while splenomegaly persists 1
- This is the single most critical intervention to prevent splenic rupture, which represents the most common potentially fatal complication 2
- Bed rest as tolerated and reduction of activity are recommended during the acute phase 1
Supportive Care
Treatment is primarily supportive, as infectious mononucleosis is generally self-limited 1, 2:
- Symptomatic management with analgesics for fever and pharyngitis 1
- Adequate hydration and rest 1
- No specific antiviral therapy is indicated for immunocompetent patients 3
Monitoring for Complications
Splenic Complications
- Spontaneous splenic rupture occurs in 0.1-0.5% of patients and is potentially life-threatening 1
- Splenic infarction is a rare but possibly underdiagnosed complication, particularly in adults 4
- Patients should be counseled to seek immediate medical attention for acute left upper quadrant pain, left shoulder pain, or signs of hemodynamic instability 4, 5
- Conservative management without anticoagulation is appropriate for splenic infarction when it occurs 4
Other Serious Complications
- Monitor for hepatomegaly (occurs in approximately 10% of cases) and hepatitis 1, 3
- Watch for neurological complications including aseptic meningitis, though rare 4
- Peritonsillar abscess can occur as a bacterial superinfection 5
Clinical Pitfalls
Avoid corticosteroids in routine cases. While dexamethasone may be considered for severe pharyngeal edema causing airway compromise, it may potentially increase risk of bacterial superinfection and complications like peritonsillar abscess 5
Do not prescribe ampicillin or amoxicillin, as these cause a characteristic maculopapular rash in 10-45% of patients with infectious mononucleosis 1
Expected Clinical Course
- Fatigue may be profound but typically resolves within 3 months 1
- Most patients have an uneventful recovery with supportive care alone 1
- Infectious mononucleosis is a risk factor for chronic fatigue syndrome in some patients 1
Special Populations
In immunocompromised patients (including those on immunosuppressive therapy), primary EBV infection carries particular risk and may require antiviral agents such as ganciclovir or foscarnet, despite limited evidence 6