Infectious Mononucleosis

Question 1

What is infectious mononucleosis?

Answer 1

Contagious illness/ infection: The virus that causes the infection (Epstein-Barr virus) is spread through saliva.
- Also known as glandular fever/mono/ “kissing disease” 
- Characterised by the classic triad of fever, pharyngitis, and lymphadenopathy, along with atypical lymphocytosis (increase in WBC)

Question 2

What causes infectious mononucleosis?

Answer 2

EBV (Epstein-Barr virus) is a herpes virus (dsDNA), present in pharyngeal secretions of infected individuals and is transmitted by close contact, e.g. kissing or sharing eating utensils. 

Question 3

What are the risk factors for infectious mononucleosis ?

Answer 3

sexual activity and kissing. 

Question 4

What are the presenting symptoms/ signs of infectious mononucelosis?

Answer 4

Has 6 week incubation period. Symptoms occur in adolescents and young adults for up to 2-4 weeks. Young children are often asymptomatic.
- Fever, Fatigue, Malaise
- Splenomegaly
- Pharyngitis or Tonsilitis (Sore Throat)
- Bilateral cervical lymphadenopathy
- Abdominal Pain
- Hepatomegaly & Jaundice
- Maculopapular Rash → develops in 99% of patients who take ampicillin/amoxicillin while they have infectious mononucleosis

Question 5

What investigations are used to diagnose/ monitor infectious mononucleosis?

Answer 5

1. Monospot Test (Heterophile antibody test) → Positive heterophile antibodies
2. Positive EBV-Specific antibodies → IgG to EBV nuclear antigens appear 6-12 weeks after infection and are lifelong.
3. LFTs → elevated AST and ALT
4. FBC → lymphocytosis and neutropenia
   - Blood Film ⇒ atypical lymphocytes

Question 6

How is infectious mononucleosis managed?

Answer 6

Management is mainly supportive → rest, fluids, avoid alcohol
- Avoid physical activity due to risk of splenic rupture (for 4 weeks)
- Analgesics / Antipyretics (reduce fevers)→ acetaminophen (paracetamol)
- Corticosteroids in severe cases (prednisolone)