Download Infectious mononucleosis

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
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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
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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 fL
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 antibodiesMonospot 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
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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. 2nd ed. New York: Lippincott Williams &
Wilkins; 2007.