An outbreak of e-cigarette- or vaping product–associated lung injury (EVALI) began in the United States in 2019. Approximately 66% of patients have been male and 80% are under age 35. Over 95% of reported cases required hospitalization: 47% were admitted to intensive care, 22% were intubated, and many died. Based on the characteristics of these patients, the diagnosis of EVALI requires reported use of e-cigarette or vaping products within 3 months of symptom onset, compatible chest imaging findings, and an evaluation that excludes infectious etiologies.
No single causative agent has been identified. The majority of cases involved vaping products containing tetrahydrocannabinol (THC) or nicotine or both. Postulated factors contributing to the development of EVALI include e-cigarette flavorings, exposure to diacetyl (a popcorn flavoring that has been associated with lung injury), THC, adulteration of THC, adulteration of delivery devices, and vitamin E acetate (used as a thickening agent).
Patients with EVALI have respiratory symptoms (95%), including cough, shortness of breath, and chest pain; gastrointestinal symptoms (77%), including nausea, vomiting, and diarrhea; and constitutional symptoms (85%), including fever, chills, and weight loss). The illness is usually acute to subacute with patients having symptoms for days to weeks before seeking health care.
Tachycardia and tachypnea are present in 55% and 45% of patients, respectively. Of note, 57% of cases have a recorded room air oxygen saturation of less than 95%. Given the nonspecific nature of the presentation especially during influenza season and the COVID-19 pandemic, providers must have a high degree of clinical suspicion and ask patients specifically about vaping.
There are no laboratory findings specific for the diagnosis of EVALI. There may be leukocytosis, elevated C-reactive protein, and elevated erythrocyte sedimentation rate.
Case series of chest imaging findings in EVALI show various patterns of lung injury. Chest radiographs typically show bilateral pulmonary opacities. Chest CT scans are nonspecific and may show patterns seen in other disorders, such as hypersensitivity pneumonitis, ARDS, diffuse alveolar hemorrhage, acute eosinophilic pneumonia, lipoid pneumonia, giant cell interstitial pneumonia, and organizing pneumonia.
The differential diagnosis is broad for a patient with respiratory and gastrointestinal symptoms and bilateral pulmonary infiltrates. The first diagnostic considerations are CAP and COVID-19. The EVALI case definition requires a negative work-up for infectious causes. Other diagnoses to consider include acute eosinophilic pneumonia, ARDS, hypersensitivity pneumonitis, lipoid pneumonia, and organizing pneumonia. Influenza testing should be done in season, and SARS-CoV-2 testing, as indicated.
The natural progression of EVALI is not known. In published reports of hospitalized patients with EVALI who have received corticosteroids, rapid improvement has been described.