Doctors initially suspected the teen had bronchiolitis - a lung condition usually caused by a bacterial or viral infection - but tests came back negative for infection. Many of the 2,000 vaping illness patients in the United States have damage in the spongelike tissue of their lungs called alveoli, or air sacs. That type of injury wasn't found in the Canadian teenager.
Instead, the condition of his lungs suggested a potential case of bronchiolitis obliterans, the medical term for popcorn lung. The ailment, which affects airways in the lungs, took its name from the cases of workers who developed it after inhaling the fumes of a heated flavoring agent at microwave popcorn plants nearly two decades ago. That chemical, diacetyl, is no longer used in most factories.
Because diacetyl is present in many e-cigarette flavors, health officials have worried that popcorn lung could afflict vapers. The American Lung Association called for the FDA to require that diacetyl and other hazardous chemicals be removed from e-cigarette cartridges.
"This is an urgent issue for public health, especially given the popularity of e-cigarettes among youth," the association said in a blog post.
The study of the Canadian boy, which pointed to inhalation of flavoring agents as a possible cause for his illness, could be the first report linking vaping to popcorn lung. The doctors noted, however, that the "exact mechanism of injury and causative agent are unknown." A more thorough lung biopsy was deemed unsafe, CBC News reported, and the teen had thrown away his used vaping cartridges.
The teen's doctors said their research underscores "the need for further research into all potentially toxic components of e-liquids and tighter regulation of e-cigarettes."