One of the Herpes virus family, and like other herpesviruses (herpes, varicella) becomes latent in the body after infection, in the case of EBV in B-lymphocytes. Immune system has developed specific strategies over the course of human evolution to control it – hence specific immunodeficiencies such as Duncan’s syndrome where EBV appears to be the only infection that becomes problematic (even catastrophic).
Associated with a number of tumours, including non-Hodgkin’s lymphoma, Burkitt Lymphoma (especially in Africa), nasopharyngeal carcinoma.
In most children, a mild febrile illness, with lymphadenopathy (“glandular fever” or infectious mononucleosis), sore throat (can be severe). Failure to improve with antibiotics is a clue! Peak age for severe presentations is teenagers – “kissing disease” (sexually transmitted!? Edinburgh students study found lower rates if routine barrier methods used). Prolonged incubation period of 30-50 days!
Classically rash triggered by amoxicillin (which is why amoxicillin isn’t recommended for sore throats, but rash can be seen with penicillin too) – maculopapular, sometimes petechial and/or urticarial, which is rather more suggestive.
On examination, hepatosplenomegaly can be seen.
Blood film characteristically shows atypical lymphocytosis. Monospot test (for “heterophile” antibodies, against horse blood cells, characteristic of EBV) only 70-90% sensitive, even worse under 4yrs of age. May also be negative if done too early. Also prone to false positives although this is rare (lymphoma, hepatitis).
Serology is a bit complicated – anti VCA (viral capsid antigen) IgM comes up first, IgG follows after 2-4 weeks then persists for life. Anti EA (early antigen) IgG is an unusual one which comes up quickly and then disappears after 3-6 months. EBNA (ENV nuclear antigen) only comes up after a few months. There are false negatives (usually because illness resolves before any antibodies appear) and false positives.
If important to know, do PCR.
Mild hepatitis and cholestasis pretty common. So can be confused with autoimmune hepatitis, especially since both can give positive IM tests.
Rarer features are dacrocystitis, pneumonia, myocarditis, low platelets and neutrophils, interstitial nephritis, encephalitis. Haemophagocytic syndrome. 20x higher risk of Guillain Barre syndrome after EBV
Splenic rupture after EBV has been reported but is very rare. Advice usually given to avoid contact sports. In ultrasound studies, peak spleen size is typically noted within the first 2 weeks of illness, but may extend to 3.5 weeks. The majority of spleen injuries occur within the first 21 days of illness and are exceedingly rare at >28 days, so one month avoidance probably sufficient.
A minority develop chronic fatigue type symptoms.