What is the best treatment regimen for splenomegaly due to infectious mononucleosis (mono)?

Treatment of Splenomegaly Due to Infectious Mononucleosis

The best treatment for splenomegaly due to infectious mononucleosis is primarily supportive care with activity restriction for at least 8 weeks or until splenomegaly resolves, to prevent the potentially life-threatening complication of splenic rupture. 1

Diagnosis Confirmation

• Complete blood count with differential to evaluate for:

  • Lymphocytosis (≥50% of white blood cells)
  • Atypical lymphocytes (>10% of total lymphocyte count)
  • Peripheral blood leukocytosis 1

• Confirm diagnosis with:

  • Monospot test (heterophile antibodies)
  • If monospot negative but clinical suspicion high, test for antibodies to viral capsid antigens 1
  • Abdominal ultrasound to confirm and quantify splenomegaly 2

Treatment Approach

Conservative Management (First-Line)

• Supportive care is the mainstay of treatment 1
• Activity recommendations:
  • Reduction of activity and bed rest as tolerated
  • Strict avoidance of contact sports or strenuous exercise for 8 weeks or while splenomegaly is present 1
  • Patient education about avoiding any activities that risk abdominal trauma

Monitoring

• Regular physical examination to assess spleen size
• Consider follow-up ultrasound to document resolution of splenomegaly 2
• Monitor for warning signs of splenic complications:
  • Left upper quadrant or referred left shoulder pain
  • Sudden onset of abdominal pain
  • Signs of hemodynamic instability (tachycardia, hypotension)

Management of Complications

Splenic Rupture

Splenic rupture occurs in 0.1-0.5% of infectious mononucleosis cases and is potentially life-threatening 1.

Hemodynamically Stable Patients

• Consider diagnostic imaging:
  • CT scan
  • Abdominal ultrasound
  • Consider angiography in select cases 3
• Some cases may be managed non-operatively with:
  • Close monitoring in hospital setting
  • Serial hemoglobin measurements
  • Bed rest
  • Consideration of splenic artery embolization in appropriate cases 3

Hemodynamically Unstable Patients

• Emergency splenectomy remains the standard of care for unstable patients with splenic rupture 4
• Peritoneal lavage may aid diagnosis in unstable patients 5

Additional Considerations

• Fatigue management: Patients should be counseled that fatigue may be profound but typically resolves within three months 1
• Antipyretics and analgesics may be used for symptomatic relief of fever and sore throat
• Hydration and adequate nutrition should be encouraged

Pitfalls to Avoid

• Premature return to physical activity before resolution of splenomegaly
• Failure to educate patients about the risk of splenic rupture
• Missing the diagnosis of splenic rupture, which can present with left upper quadrant pain and referred left shoulder pain
• Unnecessary splenectomy in cases that could be managed conservatively

While older literature advocated for emergency splenectomy in all cases of splenic rupture 4, 5, more recent evidence suggests that selected stable patients may be managed non-operatively, potentially with the aid of interventional radiology techniques such as splenic artery embolization 3.