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Background
- Caused by Epstein-Barr virus
- CMV and HHV-6 may cause mononucleosis-like illnesses
Clinical Features
- Triad of:
- Fever
- Pharyngitis
- Lymphadenopathy
- Symptoms
- abrupt or insidious, ha, fever & malaise common w/ st & lad to follow
- Rash in 10-15% usu btwn 4th-6th day of illness
- red macular or maculopapular morbilliform rash of trunk & upper arms
- occ involves face, thigh & legs, periorbital & eyelid edema in 50% of cases
- Previously treated at strep throat
- Morbilliform rash can develop[1]
- 95% of patients on amoxicillin or ampicillin
- 40-60% with other beta-lactams
Differential Diagnosis
Bacterial infections
Viral infections
Noninfectious
Other
Diagnosis
Work-up
- CBC
- BMP
- LFTs
- Heterophile antibody (monospot) test
- EBV IgM Assay
Evaluation
- Clinical features
- Lab features
- CBC
- Lymphocytosis (≥50% lymphocytes)
- 10% or more atypical lymphocytes
- LFTs
- Elevations in AST and ALT is expected up to 5x
- Heterophile antibody (monospot) test
- Up to 25% of pts in 1st week of symptoms may have false negative test[3]
- 10% of adult pts w/ EBV infection will be persistently negative
- Up to 50% of pediatric pts will be persistently negative[4]
- EBV IgM Assay
- Carries 97% sensitivity and 94% specificity at symptom onset[5]
- Amoxicillin reaction is helpful in diagnosis
- Amoxicillin in pt w/ EBV will cause maculopapular rash in most
- Suspected mononucleosis during pregnancy (also need to r/o other pathology):
- Epstein Barr Virus, Cytomegalovirus, and HIV
Management
- Supportive
- Avoid contact sports for 1-2 months[6]
Disposition
References
- ↑ Luzuriaga K and Sullivan JL. Infectious mononucleosis. N Engl J Med. 2010; 362:1993-2000.
- ↑ Melio, Frantz, and Laurel Berge. “Upper Respiratory Tract Infection.” In Rosen’s Emergency Medicine., 8th ed. Vol. 1, n.d.
- ↑ Pitetti RD, Laus, S, and Wadowsky, RM. Clinical evaluation of a quantitative real time polymerase chain reaction assay for diagnosis of primary Epstein-Barr virus infection in children. Pediatr Infect Dis J. 2003; 22:736–739.
- ↑ Papesch M and Watkins R. Epstein-Barr virus infectious mononucleosis. Clin Otolaryngol Allied Sci. 2001; 26(1):3-8.
- ↑ Bruu, AL, et al. Evaluation of 12 commercial tests for detection of Epstein-Barr virus-specific and heterophile antibodies. Clin Diagn Lab Immunol. 2000; 7:451–456.
- ↑ O'Connor TE, Skinner LJ, Kiely P, Fenton JE. Return to contact sports following infectious mononucleosis: the role of serial ultrasonography. Ear Nose Throat J. 2011 Aug;90(8):E21-4.