Which viral illness is characterized by fatigue and enlarged lymph nodes?

• A. Influenza
• B. Dengue
• C. Cytomegalovirus
• D. Mononucleosis

Answer: (D)

Fatigue with enlarged lymph nodes is a classic sign of infectious mononucleosis caused by Epstein-Barr virus. This illness often starts with notable fatigue and fever, followed by sore throat and tender lymphadenopathy, especially in the neck. The swollen nodes come from immune activation in lymphoid tissues as the body tackles EBV. Some patients may have mild liver involvement and, importantly, the spleen can enlarge, so activities that risk abdominal impact are avoided until cleared. Diagnosis is supported by a heterophile antibody test (Monospot) and EBV-specific serology if needed. While other viruses can cause fatigue, influenza typically presents with abrupt fever and respiratory symptoms; dengue features high fever with severe systemic symptoms and rash; cytomegalovirus can mimic mono but the combination of fatigue with prominent lymph node enlargement is most characteristic of infectious mononucleosis.