The CDC issued a health advisory on Aug. 30, warning of severe pulmonary diseases associated with e-cigarette use, including 215 reported cases and one confirmed death.
Since then, the New England Journal of Medicine published a Sept. 6 study linking a cluster of respiratory illness cases identified on CT scans to e-cigarette use. A group of U.S. researchers analyzed literature on the topic, summarizing imaging findings to help radiologists identify signs of vaping-related lung injuries. The results were published Oct. 8 in the American Journal of Roentgenology.
“The diagnosis of lung injury due to vaping may be made by establishing a temporal relationship between change in vaping habits and onset of lung disease, exclusion of other causes of lung disease (e.g., infection, other drug or exposure, connective tissue disease, and so on), and stabilization or improvement with cessation of vaping and possibly with corticosteroid treatment,” explained Travis S. Henry, with the University of California San Francisco’s Department of Radiology. “It is critical for the radiologist to recognize...that any of the following patterns may be seen with vaping, and thus the radiologist may be the first person to prompt the clinical team to ask about relevant exposures.”
Patterns that radiologists should watch out for include:
- Hypersensitivity Pneumonitis (HP): An HP pattern has been seen in two case reports, but neither has had histologic proof. According to Henry et al., typical findings on CT will include “symmetric upper lung–predominant and midlung-predominant ground-glass opacity (GGO), poorly defined centrilobular nodules, and occasionally mosaic attenuation reflective of air trapping.”
- Diffuse Alveolar Hemorrhage: There’s been one case report in the literature to date. Chest x-ray or CT by itself isn’t enough to separate this from other lung opacities, the researchers noted. However, patients may be “anemic, and bronchoalveolar lavage with persistent or increasingly bloody aliquots confirms the diagnosis.”
- Acute Eosinophilic Pneumonia: Also known as acute lung injury (ALI), ALI has been reported from vaping in one case. This injury often occurs with first-time vape use or an increase in usage. Recent cases have been difficult to diagnose due to “nonspecific manifestations and the absence of peripheral eosinophilia at the time of presentation.”
- Organizing Pneumonia (OP): Reported in two patients thus far, OP is a common response to lung injury “characterized by fibroblast proliferation and collagen deposition, the most typical CT findings are bilateral patchy GGO, consolidation, or both in peripheral or perilobular distribution.” The “reverse halo” or “atoll” sign can also indicate OP, the researchers explained.
- Lipoid Pneumonia: Three cases have been tied to lipid materials in the flavoring agents of vaping products. “The presence of lipid-laden macrophages on (bronchoalveolar lavage) or foreign body reaction around lipid at histology can confirm diagnosis.”
- Giant Cell Interstitial Pneumonia: A rare occurrence, Henry et. al. found one pathologically proven case which they associated with trace amounts of cobalt in the patient’s vape pen.
Henry and colleagues acknowledged there are “likely” a number of other “pulmonary manifestations” they did not touch on due to the many differences in e-cigarettes and cartridges. If a reader does see any of the patterns described, however, they should take action.
“When the radiologist sees one of these patterns of lung injury, it is important to raise the possibility of vaping-induced lung injury because cessation of vaping is an important step in treatment,” the researchers concluded.