A comparative analysis of acute eosinophilic pneumonia associated with smoking and vaping.

Acute eosinophilic pneumonia (AEP) is an uncommon cause of respiratory failure mimicking acute respiratory distress syndrome. AEP is characterized by fever (may not always be present), rapid onset of respiratory symptoms (typically less than a week but up to a month), chest infiltrate on radiologic imaging, and eosinophilic infiltration of the pulmonary parenchyma in the absence of any known causes of pulmonary eosinophilia. 1 De Giacomi F Vassallo R Yi ES Ryu JH. Acute eosinophilic pneumonia. causes, diagnosis, and management. Am J Respir Crit Care Med. 2018 Mar 15; 197: 728-736 Crossref PubMed Scopus (83) Google Scholar The eosinophilic infiltration needs to be confirmed by either a lung biopsy or bronchoalveolar lavage (BAL), demonstrating >25% eosinophils. Although many cases are idiopathic, a strong association has been established between AEP and smoking. 2 Uchiyama H Suda T Nakamura Y Shirai M Gemma H Shirai T et al. Alterations in smoking habits are associated with acute eosinophilic pneumonia. Chest. 2008 May 1; 133: 1174-1180 Abstract Full Text Full Text PDF PubMed Scopus (120) Google Scholar AEP is often seen in patients who are new smokers, resumed smoking after quitting, or recently increased the quantity of smoking. An outbreak of electronic cigarette and vaping associated lung injury (EVALI) occurred in the U.S. in the summer of 2019. 3 Werner AK Koumans EH Chatham-Stephens K Salvatore PP Armatas C Byers P et al. Hospitalizations and deaths associated with EVALI. N Engl J Med. 2020; 382 (Apr 23): 1589-1598 Crossref PubMed Scopus (101) Google Scholar A rare subset of these patients was also reported to have suffered from AEP. 4 Wolf M Richards J. Acute eosinophilic pneumonia due to vaping-associated lung injury. J Crit Care Med. 2020; 6 (Nov 7): 259-262 Crossref Google Scholar No study has previously compared the clinical, laboratory and radiologic parameters in patients with AEP secondary to smoking and vaping. This manuscript aims to compare the similarities and dissimilarities between the patients who had suffered from smoking-associated AEP (SA-AEP) versus vaping-associated AEP (VA-AEP).