Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ DEFINITION ++ Infectious mononucleosis is defined as any blood lymphocytosis induced in response to an infectious agent. Usually greater than 50% of the circulating white cells are lymphocytes, more than 10% of which have the morphology of reactive lymphocytes (Figure 53–1). Table 53–1 lists the etiologic agents that produce mononucleosis. Pharyngeal form: — A sore throat is preceded by 1 to 2 weeks of lethargy. — Epstein-Barr virus (EBV) generally is the cause. Glandular form without pharyngitis: — Lymph node enlargement occurs. — The usual cause is an agent other than EBV (eg, Toxoplasma gondii). Typhoidal form: — Lethargy with fever or diarrhea without pharyngitis, usually as a consequence of cytomegalovirus (CMV). ++ FIGURE 53–1 A–D. Blood films from patients with Epstein-Barr virus–induced mononucleosis. These reactive lymphocytes exhibit the characteristic changes seen in patients with infectious mononucleosis: large lymphocytes with abundant cytoplasm. The cytoplasmic margin often spreads around (is indented by) neighboring red cells, and the margin may take on a densely basophilic coloration. This type of reactive T lymphocyte may be seen in a variety of diseases and is not a specific change but is characteristic for Epstein-Barr virus infection. (Reproduced with permission from Lichtman MA, Shafer MS, Felgar RE, et al: Lichtman’s Atlas of Hematology 2016. New York, NY: McGraw Hill; 2017. www.accessmedicine.com.) Graphic Jump LocationView Full Size||Download Slide (.ppt) ++ Table Graphic Jump Location|Download (.pdf)|Print TABLE 53–1 ETIOLOGIC AGENTS ASSOCIATED WITH MONONUCLEOSIS SYNDROME Epstein-Barr virus Hepatitis A Cytomegalovirus Adenovirus Human immunodeficiency virus Toxoplasma gondii Human herpes virus-6 Bartonella henselae Metapneumovirus Brucella abortus Rubella +++ ETIOLOGY AND PATHOGENESIS ++ Causes are either of two members of the herpes virus family: EBV or CMV. After the early phase of fever, which lasts for 3 to 7 days, laboratory abnormalities include a blood lymphocyte proportion greater than 50%, often with greater than 10% reactive lymphocytes. Table 53–2 lists other complications of EBV and CMV mononucleosis. ++Table Graphic Jump LocationTABLE 53–2COMPLICATIONS IN PATIENTS WITH EBV OR CMV MONONUCLEOSISView Table||Download (.pdf) TABLE 53–2 COMPLICATIONS IN PATIENTS WITH EBV OR CMV MONONUCLEOSIS EBV CMV Hemolytic anemia ++ + Thrombocytopenia + + Aplastic anemia + – Splenic rupture + – Jaundice (age >25 years) ++ ++ Guillain-Barréa + ++ Encephalitisa ++ +/– Pneumonitisa +/– + Myocarditisa + – B-cell lymphoma + – Agammaglobulinemia + – CMV, cytomegalovirus; EBV, Epstein-Barr virus.aCan occur without mononucleosis syndrome. ++, common; +, infrequent; +/–, uncommon; –, not observed. +++ FEATURES OF MONONUCLEOSIS CAUSED BY EACH ETIOLOGIC AGENT ++ Table 53–3 list the signs and symptoms associated with EBV and CMV mononucleosis. Target cell for EBV mononucleosis is the B lymphocyte. Target cell for CMV mononucleosis is the macrophage. The “mononucleosis” for both is an increase in reactive ... Your Access profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth