Infectious mononucleosis

Question 1

Define

Answer 1

Clinical syndrome of fever, lymphadenopathy, pharyngitis with atypical lymphocytosis caused by primary EBV infection

AKA glandular fever

(Fever, Atypical lymphocytes, Oedema/erythema of pharynx, Sore throat, POSTERIOR CERVICAL lymphadenopathy, splenomegaly – DON’T GIVE AMOXICILLIN (will cause maculopapular rash) and AVOID CONTACT SPORT (risk of rupturing spleen)

Question 2

Causes

Answer 2

EBV is a gamma-Herpes virus (dsDNA)

It is found in the pharyngeal secretions of infected individuals and is transmitted by close contact (e.g. kissing, sharing eating utensils)

EBV infection of the epithelial cells of the oropharynx leads to B cell infection

The infected B cells disseminate EBV across the body leading to a humoral and cellular immune response

Atypical lymphocytes in the peripheral blood are a classic feature of infectious mononucleosis

EBV remains latent in lymphocytes

Reactivation may occur following stress or immunosuppression

Question 3

Epidemiology

Answer 3

COMMON

TWO age peaks:

1-6 yrs

14-20 yrs

Question 4

Symptoms

Answer 4

Incubation period: 4-8 weeks

Abrupt onset of symptoms:

• Sore throat
• Fever
• Fatigue
• Headache
• Malaise
• Anorexia
• Sweating
• Abdominal pain

Question 5

Signs

Answer 5

PYREXIA

Oedema and erythema of the pharynx

White/creamy exudate on the tonsils

Palatal petechiae

Cervical/generalised lymphadenopathy

Splenomegaly

Hepatomegaly

Jaundice (5-10%)

Widespread maculopapular rash (in patients who have received ampicillin)

Question 6

Management

Answer 6

Bed rest

Paracetamol and NSAIDs - helps with fever, malaise

Corticosteroids in SEVERE cases

IMPORTANT: do NOT give AMPICILLIN or AMOXICILLIN if infectious mononucleosis is suspected - nearly 100% of patients with glandular fever develop a maculopapular rash

Advice - avoid contact sports for 2 weeks (because of risk of rupturing your spleen)

Question 7

Complication

Answer 7

Lethargy for several months

Respiratory - airway obstruction from oedematous pharynx, secondary bacterial throat infection, pneumonitis

Haematological - haemolytic or aplastic anaemia, thrombocytopenia

GI/Renal - splenic rupture, fulminant hepatitis, pancreatitis, mesenteric adenitis, renal failure

CNS - Guillain-Barre syndrome, encephalitis, viral meningitis

EBV-associated malignancy - Burkitt’s lymphoma (in sub-Saharan Africa), nasopharyngeal cancer, Hodgkin’s lymphoma

Question 8

prognosis

Answer 8

Most make uncomplicated recovery (within 3 weeks)

Immunodeficiency and death are VERY RARE