Acute Eosinophilic Pneumonia Presenting with an Elevated Procalcitonin Level: A Rare Laboratory Finding.

Objective: Challenging differential diagnosis Background: We present the case of a 33-year-old female who was transferred to a tertiary care hospital because of acute respiratory failure. Case Report: History, imaging, and laboratory testing (including an elevated procalcitonin level) were consistent with a diagnosis of bacterial pneumonia. However, despite broad spectrum intravenous antibiotics, her condition worsened. Shortly after transfer to our hospital, she required intubation and mechanical ventilation. Bronchoscopy with bronchoalveolar lavage (BAL) was performed and a diagnosis of acute eosinophilic pneumonia was made. After discontinuation of antibiotics and initiation of steroids she improved quickly. Conclusions: Our case highlights the importance of considering alternative diagnoses in patients who appear to have bacterial lower respiratory tract infection, even in those with elevated procalcitonin levels.