From the Guidelines
The most appropriate initial diagnostic test for mononucleosis is the monospot test (heterophile antibody test), but if the results are negative, additional laboratory testing such as EBV antibody testing for IgG and IgM to viral capsid antigen (VCA) and Epstein-Barr nuclear antigen (EBNA) should be considered. The diagnostic approach for infectious mononucleosis typically begins with clinical evaluation of symptoms such as fever, sore throat, fatigue, lymphadenopathy, and splenomegaly 1. Laboratory testing includes a complete blood count, which often shows lymphocytosis with atypical lymphocytes.
Key Diagnostic Tests
- Monospot test (heterophile antibody test)
- EBV antibody testing for IgG and IgM to viral capsid antigen (VCA) and Epstein-Barr nuclear antigen (EBNA) if the monospot test is negative
- Complete blood count to show lymphocytosis with atypical lymphocytes
The management of mononucleosis is primarily supportive as the disease is self-limiting 1. Treatment includes:
- Adequate rest
- Hydration
- Acetaminophen or NSAIDs for fever and pain relief, with specific dosing being acetaminophen 650-1000mg every 6 hours as needed (not exceeding 4000mg daily) or ibuprofen 400-600mg every 6-8 hours with food
- Corticosteroids like prednisone (40-60mg daily for 5-7 days) may be considered in severe cases with significant tonsillar swelling causing airway obstruction, but are not routinely recommended 1.
Important Considerations
- Patients should avoid contact sports for at least 3-4 weeks to prevent splenic rupture
- Regular follow-up is necessary to monitor for complications
- Alcohol should be avoided during illness and recovery due to potential liver involvement
- Antibiotics, particularly ampicillin and amoxicillin, should be avoided as they can cause a rash in EBV-infected patients 1. Most patients recover completely within 2-4 weeks, though fatigue may persist longer.
From the Research
Diagnostic Approach for Mononucleosis
The diagnostic approach for mononucleosis involves a combination of clinical, hematologic, and serologic manifestations of the illness 2. The classic triad of fever, pharyngitis, and cervical lymphadenopathy is a common presentation of the disease. Laboratory tests, such as a complete blood count with differential, can help assess for lymphocytosis with a predominance of atypical lymphocytes 3.
Laboratory Tests
- Complete blood count (CBC) with differential to assess for lymphocytosis and atypical lymphocytes 3
- Rapid heterophile antibody test, such as the Monospot test, which has a sensitivity of 87% and specificity of 91% 3
- Epstein-Barr viral capsid antigen-antibody testing, which is more sensitive and specific but more expensive and takes longer to process than the rapid heterophile antibody test 3
- Lymphocyte count, which can be used as a diagnostic screen in adults with suspected Epstein-Barr virus infectious mononucleosis 4
Interpretation of Test Results
- A positive heterophile antibody test result is indicative of infectious mononucleosis 2
- A negative heterophile antibody test result does not rule out infectious mononucleosis, especially in children younger than five years and in adults during the first week of illness 3
- The presence of elevated liver enzymes increases clinical suspicion for infectious mononucleosis in the setting of a negative heterophile antibody test result 3
- A lymphocyte count of ≤4 × 10(9) /L is a highly reliable predictor of a negative Monospot result, particularly in adults older than 18 years 4
Management of Mononucleosis
The management of mononucleosis is mainly supportive, with a focus on managing symptoms and preventing complications 2, 3, 5. This includes:
- Reduction of activity and bed rest as tolerated
- Avoidance of contact sports or strenuous exercise for 3-8 weeks or while splenomegaly is still present
- Monitoring for potential complications, such as splenic rupture, which is the most feared complication of infectious mononucleosis 5