Infectious Mononucleosis (EBV)

Transmission

• • Epstein-Barr virus can be found in throat washings of patients with infectious mononucleosis and for about 18 months after the infection.
  •  It can also be cultured from throat washings of 10–20% of healthy adults.
  • Transmission in young adults occurs through salivary contact such as kissing or sharing food and drinks but only a minority of patients recall contact with a known case.

Clinical features 

• triad of
  • fever
    • Fever is highest in the first week and resolves over a 10–14 day period
  • sore throat
  • generalised lymphadenopathy
• Other common symptoms are
  • chills, sweats, anorexia, fatigue and malaise. Myalgias, headaches and abdominal fullness
  • it is common for cervical nodes in the posterior triangle to be involved in EBV infection. 
  • This is not usually the case in streptococcal pharyngitis, which is more likely to have very tender submandibular nodes.
  • Epstein-Barr virus related palatal petechiae, located at the junction of the hard and soft palates, occurs in 25–60% of cases
  • Periorbital oedema
  • Maculopapular rashes are seen in 90% of patients with EBV who receive amoxycillin or ampicillin.
  • Splenomegaly
  • Hepatomegaly

Complications

• tonsils are sufficiently enlarged that they endanger the airway
• Fulminant liver failure
  • is extremely unusual
• Splenomegaly/Splenic rupture
  • can occur so care should be taken with palpating the spleen and contact sports should be advised against in the first three weeks or until the splenomegaly resolves
• Auto immune hamolysis
  • Very severe cases involving marked disturbances in liver and renal function as well as severe cytopaenias may be manifestations of the haemophagocytic syndrome which generally requires tissue biopsy to make a diagnosis.
• Myocarditis
• GBS

Investigations

• EBV specific serology will usually make the diagnosis.
  • IgG and IgM antibodies against the viral capsid antigens (VCA) appear early on. 
  • The IgM antibodies are present for several months and do not reappear so are the most useful for diagnosing acute infection.
  • Titres of anti-VCA IgG do not always rise, so it is not a useful marker of recent infection. 
  • IgG antibodies against EpsteinBarr nuclear antigens usually take 3–4 weeks to appear so their appearance can sometimes be useful in diagnosing recent infection.
    • Once present, they persist for life

Management

• Supportive
• Given that EBV is known to have oncogenic potential
  • immunosuppressive therapy such as corticosteroids should be avoided unless really needed. 
  • The indications for using corticosteroids are:
    • severe upper airway obstruction
    • acute haemolytic anaemia
    • severe thrombocytopenia
    • severe cardiac involvement or neurologic disease

• Summary
  • Infectious mononucleosis is a common illness of adolescents and young adults
  • The majority recover uneventfully over several weeks
  • Severe or complicated cases occasionally occur and may require hospital admission
  • There is no rule for antivirals and only a few specific indications for corticosteroids.