Correct
3. Eosinophilic pneumonia
Eosinophilic pneumonia (EP) and pulmonary eosinophilia are terms that are used to broadly classify the infectious and non-infectious etiologies that cause an accumulation of eosinophils in the lungs (1). Normally less than 2% of cells counted on bronchoalveolar lavage (BAL) are eosinophils. In EP, the BAL fluid sample should have a minimum of 25% eosinophils but often contains more than 40%. In addition to eosinophilic infiltration of the lungs, EP is often accompanied by peripheral blood eosinophilia, with severe peripheral eosinophilia defined as absolute eosinophilic count (AEC) greater than 5000 (2). Bacterial pneumonia is less likely given the peripheral eosinophilia and lack of improvement with antibiotic therapy. Mild peripheral eosinophilia has been seen in patients with acute asthma exacerbation but would not explain the chest x ray findings that are more consistent with pneumonia. Coccidioidomycosis and Rocky Mountain Spotted Fever are considerations, but less likely given the clinical presentation.
Physical exam
On admission, the patient was found to be febrile with temperature of 38.9° C, tachycardic to 132 beats per minute and had a blood pressure of 111/70 mm Hg without vasopressor support. While mechanically ventilated, the patient was saturating at 95% with an FiO2 of 100% and positive end expiratory pressure (PEEP) of 9. Diffuse wheezing was present in all lung fields. The skin exam was notable for a confluent, erythematous, nonpapular rash covering the torso, bilateral flanks and posterior thighs. The remainder of the exam was unremarkable.
Laboratory and radiology
CBC on admission was significant for a leukocytosis of 51,000 (previously 22,000) with an absolute eosinophil count of 22.9. Coagulation studies were notable for an elevated PT/INR, fibrinogen, and D-dimer. Antithrombin III was decreased. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were slighted elevated. Lactate was normal. Ferritin was elevated at 1,661 ng/ml. Chest x-ray redemonstrated diffuse patchy opacifications and appropriate placement of the endotracheal tube Figure 1).
Figure 1. Chest X ray remonstrating diffuse patchy opacities.
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