Introduction: 

Influenza, a contagious respiratory illness caused by influenza viruses, can manifest with various symptoms and complications, ranging from mild respiratory symptoms to severe systemic involvement. We present a case of a 33-year-old female with morbid obesity who initially presented with symptoms suggestive of influenza B infection and subsequently developed complications including pericardial effusion and cardiac tamponade.

Case Presentation: 

A 33-year-old female with morbid obesity presented to the emergency department (ED) complaining of generalized malaise, cough, chest pain exacerbated by coughing, nausea, and vomiting. She denied headache, dizziness, shortness of breath, or abdominal pain. Initial vital signs were within normal limits except for a slightly elevated body temperature and tachycardia. She tested positive for influenza B infection and was discharged with supportive care and antiemetic medication. Four days later, she returned to the ED with worsening weakness, vomiting, and diarrhea. Laboratory findings revealed evidence of sepsis and pneumonia secondary to influenza B infection. Imaging studies showed pericardial effusion with early signs of tamponade, prompting emergent intervention.

Discussion: 

Influenza B infection can lead to rare but serious complications, including pericardial effusion and cardiac tamponade. Prompt recognition and management of these complications are crucial for improving patient outcomes. Early diagnosis with point-of-care ultrasound (POCUS) and echocardiography aids in timely intervention and treatment planning. Neuraminidase inhibitors and vaccines play a role in preventing and treating influenza, but there is limited data on their efficacy in severe cases.

Conclusion: 

Pericardial effusion secondary to Influenza B infection is a rare but potentially life-threatening complication. This case highlights the importance of considering influenza-related complications in patients presenting with flu-like symptoms, even in the absence of significant comorbidities. Vigilance, comprehensive diagnostic workup, and multidisciplinary management are essential for improving outcomes in such cases.