Infectious Mononucleosis Glib Riabov additional relevant history questions

Infectious Mononucleosis Glib Riabov: additional relevant history questions, interpretation of lab results, prognosis/patient education. Gukeerat Singh: additional relevant history questions, management, pathophysiology, patient education. Jeff Di Labio: Most Like Diagnosis, Narrator Brittany Belair: Differential DDX; Editor.

Hematology Case 1 Overview • • • History Physical Examination Lab Investigations: results and interpretation Assessment: DDx and most likely Dx Management Prognosis and Patient education

History 20 year old female complains of worsening fatigue over the last week or so, with associated sore throat and headaches. She also reports occasional fever and chills. She normally runs 3 miles per day, which she has been unable to do since the onset of symptoms.

Additional Relevant History Questions 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Did you notice swelling/enlargement of the lymph nodes? Do you have abdominal pain/distention? Are you experiencing any nausea? Or vomiting? Do you have cough? If “YES” (type of cough, amount, color, consistency, odor, presence of blood) Explore headaches in details (PQRSTAAAR questionnaire). Did you notice any rash? Any yellowish discoloration of the skin/sclerae? Tell me about your appetite. Do you have joint/muscle pains/night sweats/bleeding gums? Are you currently on any medications/herbs? Have you been in any sexual contact in the last 2 months and with how many partners? Do you practice safe sex? Are you currently in a relationship? (if Yes, Does your partner have similar symptoms? ) Have you recently been in contact with someone who shares similar symptoms?

Physical Exam Erythema of the throat and tonsillar pillars. Cervical lymph nodes were swollen bilaterally, tender and mobile.

Laboratory Investigations RBC 5. 24 x 1012/L Hgb 153 g/L Hct 46. 2 % MCV 87. 9 f. L MCHC 332 g/L RDW 0. 121 WBC 12. 8 x 109/L Neutrophils 24 % Lymphocytes 73% Monocytes 0% Eosinophils 3% Basophils 0% PLT 333 x 109/L Heterophil antibody screen positive Blood smear analysis normocytic, normochromic red blood cells. White blood cells are large with smudged chromatin pattern and reactive lymphocytes. Platelet morphology is normal

Interpretation of Lab Results (key findings) • Normal values of RBC, Hgb, Hct, MCV, MCHC, RDW. • Normal morphology of RBCs. • Mild elevation of WBC with lymphocytic profile of the WBC formula (characteristic for viral infections). • WBC’s morphology is abnormal showing large leucocytes with smudged chromatin pattern and reactive lymphocytes (atypical leucocytessuggestive of infectious mononucleosis). • Normal platelets with normal morphology. • Positive Heterophile antibody test-pathognomonic for infectious mononucleosis.

Differential Diagnosis with brief explanation of rationale • Acute retroviral syndrome: immune system dysfunction leading to “mononucleosis like” illness in 40 -90% of ppl. • Streptococcal tonsilopharyngitis • Acute cytomegalovirus infection: resembles mono. • Toxoplasmosis: mono-like; may also cause enlarged spleen and nodes. • Diphtheria: if unvaccinated it is possible although unlikely. • Lymphoproliferative disorders (Hodgkin’s diseaselymphogranulomatosis, leukemias) would explain S/S. • All DDx can explain the symptoms our patient is feeling including sore throat, fever/chills, headache and fatigue.

Most Likely Diagnosis with brief explanation of rationale • Infectious Mononucleosis • 1. Characteristic clinical presentation (fatigue, throat pain, headache, fever). • 2. Physical examination findings (lymphadenopathy, exudative pharyngitis). • 3. Laboratory tests (positive Heterophile antibodies. Monospot test-pathognomonic; absolute lymphocytosis; atypical monocytes).

Pathophysiology • Transmitted via contact with body secretions; mainly oropharyngeal secretions (effect is typically on B-cells/lymphocytes). • B-cells spread infection through the entire reticular-endothelial system (lymph, spleen, liver). • B-cells cause a humoral cellular response to the mononucleosis virus (EBV). • T-cells come into play and control the infection via the natural killer cells. • Cytotoxic T cells control proliferating infected B-cells. • Immune response to the infection is a fever and pharyngitis. • In rare cases mononucleosis can occur via blood transfusion.

Management Rest for 2 -3 weeks; hydration. Gargles for sore throat. Acetaminophen/NSAIDS for pain and fever. Corticosteroids if there is airway obstruction (cough, Hx of asthma, difficulty breathing). • Avoid contact sports (risk of spleen rupture due to possible enlargement with subsequent life-threatening internal bleeding). • Encourage to abstain from sharing drinks, eating utensils, kissing, etc while recovering from the infection. • •

Prognosis/Patient Education Prognosis • Benign overall (self-limited disease). • Predisposes for Hodgkin’s lymphoma (rarely). • Rare complications include: hepatitis, hemolytic anemias, encephalitis/meningitis, chronic fatigue syndrome, myocarditis/pericarditis. • Fulminant course is possible in immunocompromised patients. Patient education • Protect yourself by avoiding contact with someone who has the virus. • Avoid exchange of body secretions (do not share food, drinks, avoid sexual contact).

References 1. Toronto Notes (2012). Pediatrics. P. 57. 2. Adam et al. . Toronto Notes, 30 ed. Toronto, ON: Vojvodic Young; 2014. 3. Burke A, C. Infectious Mononucleosis. Medscape 2014. http: //emedicine. medscape. com/article/222040 -overview (accessed 15 Jan 2015). 4. Porth C. Essentials of Pathophysiology: Concepts of Altered Health States. 2 nd ed. New York: Lippincott Williams & Wilkins; 2007.