Infectious mononucleosis
Infectious mononucleosis is a systemic illness caused mainly by Epstein-Barr virus, presenting with fever, pharyngitis, and lymphadenopathy, confirmed by heterophile antibody or EBV-specific serology, and managed supportively with contact-sport restriction to prevent splenic rupture.
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What this article covers
- Overview
Systemic viral illness driven by lytic and latent B-cell infection: infectious mononucleosis is a clinical syndrome of fever, pharyngitis, and lymphadenopathy caused most often by primary…
- Epidemiology
Near-universal exposure: serologic studies show evidence of prior EBV infection in almost all adults.
- Risk factors
Close salivary contact with an infected or shedding person: kissing, sharing drinks or utensils, and close-quarters living (dormitories, military barracks) are the principal exposure routes.
- Pathophysiology
Oropharyngeal epithelial and B-lymphocyte infection: EBV first infects oropharyngeal epithelium and then establishes latent infection in B lymphocytes, driving polyclonal B-cell proliferation.
- Clinical features
Fever, pharyngitis, and lymphadenopathy define the syndrome and establish the diagnosis when they occur together in an adolescent or young adult with a compatible exposure: this clinical triad…
- Differential diagnosis
Streptococcal pharyngitis: distinguished by anterior (not posterior) cervical adenopathy, absence of splenomegaly or hepatomegaly, and a positive rapid antigen detection test in a patient meeting…
- Diagnosis
The diagnosis is established by detection of heterophile antibodies (the Monospot test) or, when that result is negative, IgM antibody to the EBV viral capsid antigen (VCA-IgM); there is no numeric…
- Management
First, confirm the diagnosis before treating and avoid aminopenicillins: do not give ampicillin or amoxicillin empirically for pharyngitis in a patient with a mononucleosis-compatible presentation…
- Complications
Splenic rupture: the most feared complication, occurring in fewer than 0.5% of cases, more common in males, typically arising spontaneously 1 to 2 weeks after symptom onset and presenting with…
- Prognosis
Excellent for uncomplicated disease: most immunocompetent patients recover fully, though fatigue can persist for 3 to 6 months.
- Prevention
No vaccine is available: there is no licensed EBV vaccine for primary prevention.
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