Infectious Mononucleosis Flashcards
how is EBV spread
droplets or saliva
eg kissing, toothbrush
EBV infection in different ages
in early childhood it will cause few symptoms and rarely result in IM
however, in young adults/teens, IM may develop
DNA Herpesvirus
HSV, EBV, cytomegalovirus
typically cause latent, recurring infections
presentation
- Sore throat
- Fever – continuous throughout day
- Enlarged lymph nodes: cervical nodes often (posterior triangle of neck)
- Sore throat, pharyngitis
- Gross tonsillar enlargement with membranous exudate
- Malaise, lethargy
- Anorexia
- Profound feeling of being unwell
what are some more obscure presentations
- jaundice/hepatitis
- haemtology: leucocytosis, atypical lymphocytes in blood film
- hepatosplenomegaly
- palatal petechiae haemorrhages
rash
mild and only seen in 25%
more common if amoxicillin is prescribed - dont give to patients with a sore throat incase it is EBV
what can rarely happen to the spleen
rupture
blood film appearance and pathology
- The virus initially replicates in epithelial cells in the pharynx (causing pharyngitis), and later in B cells. The host immune response involves cytotoxic (CD8 +) T cells against infected B lymphocytes, resulting in atypical mononuclear lymphocytes.
- The atypical lymphocytes differ from typical resting lymphocytes: larger, irregular in outline rather than round, irregular nucleus, more of cell volume taken up by cytoplasm, which is intensely basophilic (blue) indicating the presence of a lot of ribosomes.
prognosis
protracted but self-limiting
onset is insidious over several days, fever and pharyngitis last 2-4 weeks
lymphadenopathy usually resolves in 4 weeks
lethargy may persist for a lot longer
complications
- Meningoencephalitis
- Cerebellitis
- Splenic rupture – very rare
- Anaemia, thrombocytopenia
- Autoimmune phenomenon
- Treated with steroids
- Upper airway obstruction
- Increased risk of lymphoma, especially if IS
treatment
- No prescription is usually needed, fluids and rest
- Paracetamol for fever
- Avoid vigorous sport, as splenic rupture is reported
- Steroids ± acyclovir are sometimes used for the severest signs
laboratory confirmation
EBV IgM
heterophile antibody tests - monospot or Paul-Bunnell test - show heterophile Ab after 3 weeks
WBC - atypical mononuclear cells
low CRP
LFT
differentiate CMV
causes a similar illness, but there will not be any heterophile antibodies and fewer atypical lymphocytes
toxoplasmosis
protozoan parasite of cats that is transmitted to humans through undercooked meat/contact with cat litter
what can CMV and Toxo cause
congenital infection and foetal damage
how is glandular fever differentiated from tonsillitis
gross tonsillar enlargement with membranous exudate
