NCLEX Review Guide: Infectious Mononucleosis in Pediatric Patients

Causative Agent & Transmission

• Epstein-Barr Virus (EBV) is the most common cause of infectious mononucleosis, accounting for 85-95% of cases in adolescents and young adults.
• Transmission occurs through direct contact with infected saliva, earning it the nickname "kissing disease" - sharing drinks, utensils, or intimate contact are primary routes.
• Cytomegalovirus (CMV) and other viruses can also cause mono-like syndromes with similar presentations but typically milder symptoms.

Classic Triad of Symptoms

• Fever (often high-grade, 101-104°F) that may persist for 1-2 weeks and is typically the first symptom to appear.
• Severe sore throat with tonsillar enlargement, often described as the worst sore throat the patient has ever experienced.
• Lymphadenopathy, particularly posterior cervical lymph nodes, which are tender and significantly enlarged.

Additional Clinical Signs

• Splenomegaly occurs in 50-60% of patients and poses risk for splenic rupture - a medical emergency requiring immediate intervention.
• Hepatomegaly with possible mild elevation of liver enzymes (ALT, AST) indicating hepatic involvement.
• Characteristic petechial rash on the soft palate appears in about 25% of patients.
• Profound fatigue and malaise that can persist for weeks to months after acute illness resolves.

Laboratory Findings

• Monospot test (heterophile antibody test) is positive in 85-90% of adolescents and adults but frequently negative in children under 4 years.
• Complete Blood Count shows lymphocytosis with atypical lymphocytes >10% - these are large, irregular lymphocytes characteristic of viral infection.
• EBV-specific antibodies (IgM and IgG) provide definitive diagnosis when monospot is negative or clinical suspicion is high.

Supportive Care Measures

1. Rest and activity modification - encourage adequate sleep and gradual return to activities based on energy levels.
2. Hydration maintenance - encourage fluid intake of 2-3 liters daily unless contraindicated; popsicles and cool liquids soothe throat.
3. Pain and fever management - acetaminophen or ibuprofen for comfort; avoid aspirin due to Reye's syndrome risk.
4. Activity restrictions - no contact sports or heavy lifting for 4-6 weeks due to splenomegaly risk.

Patient & Family Education

• Explain that fatigue may persist for 2-3 months and encourage gradual increase in activity tolerance.
• Teach isolation precautions: avoid sharing drinks, utensils, or intimate contact until fever-free for 24 hours.
• Emphasize importance of follow-up care and monitoring for complications such as airway obstruction or splenic rupture.

Serious Complications

• Airway obstruction from massive tonsillar enlargement - monitor for stridor, difficulty swallowing, or respiratory distress.
• Splenic rupture - assess for left upper quadrant pain, shoulder pain, or signs of internal bleeding.
• Secondary bacterial infections, particularly Group A Streptococcus, requiring antibiotic therapy.
• Neurological complications (rare) including encephalitis, meningitis, or Guillain-Barré syndrome.