History

Fact Explanation
Sore throat Epstein Barr virus replicates mainly in B lymphocytes but also may replicate in the epithelial cells of the pharynx causing pharyngitis. Soreness of the throat will occur due to the inflammation of the pharynx and it is the most commonly found symptom in infectious mononucleosis.[1,2]
Fever Prostaglandins release due to the action of cytokines as a result of ongoing inflammation, reset the temperature set point in the hypothalamus at a higher level causing fever.[1]
Fatigue, malaise, need for sleep/hypersomnia Inflammation of the pharynx, releases cytokines which in turn cause fatigue and malaise which is characteristically severe in patients with infectious mononucleosis.[1]
Headache, myalgia Because of the action of cytokines.[1]
Neck or groin lumps Due to associated cervical and inguinal lymphadenopathy.[1]
Age of the patient Infectious mononucleosis commonly found in adolescents and children (10 to 30 years) and it is relatively uncommon in adults.[1]
Difficulty in breathing Rarely tonsillar enlargement and severe pharyngeal mucosal edema can cause upper airway obstruction resulting difficulty in breathing.[2]
Yellowish discoloration of eyes and mucous membranes Due to derangement of liver functions.[2]
References
  1. MARK H. EBELL. Epstein-Barr Virus Infectious Mononucleosis. Am Fam Physician.[online] 2004 Oct 1;70(7):1279-1287. viewed on: 26.05.2014 Available from: http://www.aafp.org/afp/2004/1001/p1279.html
  2. LUZURIAGA K. SULLIVAN JL. Infectious Mononucleosis. N Engl J Med.[online] 2010; 362:1993-2000. viewed on: 26.05.2014 Available from: http://www.nejm.org/doi/full/10.1056/NEJMcp1001116 DOI: 10.1056/NEJMcp1001116

Examination

Fact Explanation
Increased body temperature Usually patients' body temperature is ≥ 37.5°C (99.5°F). Pharyngeal inflammation releases cytokines which reset the temperature set point in the hypothalamus at a higher level causing increased body temperature.[1]
Inflamed pharynx Epstein Barr Virus (EBV) replicates largely in B lymphocytes but also may replicate in the epithelial cells of the pharynx causing inflammation of the pharynx.[1]
Palatal petechiae Occur transiently and not in every patient.[1,2]
Tonsillar enlargement Replication of the Epstein Barr Virus occur mainly in B lymphocytes. Therefore not only tonsils also other lymph nodes also get enlarged.[1]
Lymphadenopathy Cervical, particularly posterior cervical, auricular, axillary or inguinal lymphadenopathy is a characteristic finding in patients with infectious mononucleosis.[1]
Splenomegaly Since it is a mild splenomegaly find it may be difficult to palpate. However rarely some patients develop rupture of the spleen.[1,2]
Hepatomegaly Hepatomegaly is found in some patients, it is associated with deranged liver functions and intra hepatic cholestasis.[1,2,3]
References
  1. MARK H. EBELL. Epstein-Barr Virus Infectious Mononucleosis. Am Fam Physician.[online] 2004 Oct 1;70(7):1279-1287. viewed on: 26.05.2014 Available from: http://www.aafp.org/afp/2004/1001/p1279.html
  2. LUZURIAGA K. SULLIVAN JL. Infectious Mononucleosis. N Engl J Med.[online] 2010; 362:1993-2000. viewed on: 26.05.2014 Available from: http://www.nejm.org/doi/full/10.1056/NEJMcp1001116 DOI: 10.1056/NEJMcp1001116
  3. GONZáLEZ SALDAñA N, MONROY COLíN VA, PIñA RUIZ G, JUáREZ OLGUíN H. Clinical and laboratory characteristics of infectious mononucleosis by Epstein-Barr virus in Mexican children. BMC Res Notes [online] 2012 Jul 20:361 [viewed 28 May 2014] Available from: doi:10.1186/1756-0500-5-361

Differential Diagnoses

Fact Explanation
Streptococcal pharyngitis Important to exclude as patients with streptococcal pharyngitis will need antibiotics in the management. Absence of hepato-splenomegaly favors streptococcal pharyngitis. And also fatigue is less prominent compared to infectious mononucleosis.[1,2]
Acute cytomegalovirus (CMV) infection Serological testing (specific IgG and IgM) will help in differentiating from infectious mononucleosis.[1]
Toxoplasmosis Serological testing (specific IgG and IgM) will help in differentiating from infectious mononucleosis.[1]
Acute Human Immunodeficiency Virus infection Suspect in patients who got risk factors in the social history and also consider if they have history of diarrhea, vomiting, nausea, weight loss and examination findings such as mucocutaneous lesions, rashes.[1,2,3]
Other viral pharyngitis Patients may not have significant lymphadenopathy, fever or splenomegaly.[1]
References
  1. MARK H. EBELL. Epstein-Barr Virus Infectious Mononucleosis. Am Fam Physician.[online] 2004 Oct 1;70(7):1279-1287. viewed on: 26.05.2014 Available from: http://www.aafp.org/afp/2004/1001/p1279.html
  2. LUZURIAGA K. SULLIVAN JL. Infectious Mononucleosis. N Engl J Med.[online] 2010; 362:1993-2000. viewed on: 26.05.2014 Available from: http://www.nejm.org/doi/full/10.1056/NEJMcp1001116 DOI: 10.1056/NEJMcp1001116
  3. COHEN MS, SHAW GM, McMICHAEL AJ, HAYNES BF. Acute HIV-1 Infection. N Engl J Med.[online] 2011; 364:1943-1954. viewed on: 27.05.2014 Available from: DOI: 10.1056/NEJMra1011874

Investigations - for Diagnosis

Fact Explanation
Full Blood Count and Blood picture Absolute and relative lymphocytosis with increased proportion of atypical lymphocytes favor the diagnosis of infectious mononucleosis. According to the Hoagland’s criteria there should be at least 50% lymphocytes and at least 10% atypical lymphocytes to diagnose infectious mononucleosis.[1]
Serological tests - Heterophile antibody–latex agglutination and solid-phase immunoassay Positive heterophile antibody test help diagnosing infectious mononucleosis. This test is less sensitive, because false-negative results of heterophile antibody tests are relatively common early in the course of infection. In an acute infection, heterophile antibodies that agglutinate sheep erythrocytes are produced. This process forms the basis for the Monospot rapid latex agglutination test.[1]
Serological tests - Antibody to VCA (Epstein-Barr virus viral capsid antigen) - IgG & IgM or EBNA (Epstein-Barr nuclear antigen) Definitive diagnosis can be made using this test, specially in pregnant women where it is important. Antibody to VCA testing is better than heterophile antibody test to exclude infectious mononucleosis caused by Epstein Barr virus(EBV) as VCA-IgG and VCA-IgM are produced slightly earlier than the heterophile antibody and are more specific for EBV infection. Antibody to EBNA help distinguish between acute and previous infections as it is not detectable in serum until 6-8 weeks after the onset of symptoms.[1]
Rapid test for group A β-hemolytic streptococcus To exclude streptococcal pharyngitis.[1]
Screening test - Human Immunodeficiency virus(HIV) infection Consider in patients with risk factors in the history and findings in the clinical examination suggestive of acute HIV infection.[1,2]
References
  1. MARK H. EBELL. Epstein-Barr Virus Infectious Mononucleosis. Am Fam Physician.[online] 2004 Oct 1;70(7):1279-1287. viewed on: 26.05.2014 Available from: http://www.aafp.org/afp/2004/1001/p1279.html
  2. LUZURIAGA K. SULLIVAN JL. Infectious Mononucleosis. N Engl J Med.[online] 2010; 362:1993-2000. viewed on: 26.05.2014 Available from: http://www.nejm.org/doi/full/10.1056/NEJMcp1001116 DOI: 10.1056/NEJMcp1001116

Investigations - Followup

Fact Explanation
Ultrasound scan of the abdomen To assess the size of the spleen at 3 weeks, as it is a better guide for determining the risk of splenic rupture which usually occurs during first 4 weeks of the illness.[1]
References
  1. MARK H. EBELL. Epstein-Barr Virus Infectious Mononucleosis. Am Fam Physician.[online] 2004 Oct 1;70(7):1279-1287. viewed on: 26.05.2014 Available from: http://www.aafp.org/afp/2004/1001/p1279.html

Management - Specific Treatments

Fact Explanation
Supportive management Symptomatic treatment is the main mode of management. It is comprised of 1) Provision of adequate hydration and nutrition 2) Analgesics for myalgia, headache - non steroidal anti-inflammatory drugs or acetaminophen can be used. 3) Antipyretics such as acetaminophen for fever 4) throat lozenges, sprays or gargling with a 2% lidocaine (Xylocaine) solution to relieve pharyngeal discomfort.[1,2]
Adequate rest Bed rest is not recommended as it slower the recovery and the patients should advise to maintain adequate physical activity.[1]
Antiviral treatment - Acyclovir Not recommended.[1,2]
Corticosteroids Not recommended for uncomplicated disease. Can be used in patients with respiratory compromise(upper airway obstruction), severe pharyngeal edema, who developed complications such as hemolytic anemia or thrombocytopenia.[1,2]
Amoxicillin and ampicillin Should not be used because they may cause a morbilliform rash in patients with infectious mononucleosis.[1,2]
Prevention - splenic rupture Patients should be educated to withdraw contact or collision sports for at least 4 weeks after the onset of symptoms.[1,2]
References
  1. MARK H. EBELL. Epstein-Barr Virus Infectious Mononucleosis. Am Fam Physician.[online] 2004 Oct 1;70(7):1279-1287. viewed on: 26.05.2014 Available from: http://www.aafp.org/afp/2004/1001/p1279.html
  2. LUZURIAGA K. SULLIVAN JL. Infectious Mononucleosis. N Engl J Med.[online] 2010; 362:1993-2000. viewed on: 26.05.2014 Available from: http://www.nejm.org/doi/full/10.1056/NEJMcp1001116 DOI: 10.1056/NEJMcp1001116