Dear Doctor:

Our family is worried; my 18-year-old grandson won’t give up vaping. How many people have gotten sick? We just read about something called popcorn lung. What is that?

Dear Reader: Ever since the first cases of vaping illness were made public last August, the outbreak has made front-page news. The Centers for Disease Control and Prevention, one of several federal agencies monitoring the outbreak, publishes regular updates about the number of cases of vaping illness, as well as the deaths it has caused. As of December, at least 2,400 hospitalizations due to lung injuries associated with vaping have been reported to the CDC from all 50 states, Puerto Rico and the U.S. Virgin Islands. At least 52 people in 26 states and the District of Columbia have died. Doctors and surgeons compare the lung injuries they’re seeing to the kinds of chemical burns usually associated with industrial accidents.

But statistics can be a hard sell, particularly for teenagers. Maybe the case of a 17-year-old boy in Detroit, who recently underwent a double lung transplant after falling ill from vaping, will help make the risks seem more real.

One of the striking things about the outbreak is the number of rare lung conditions doctors are now diagnosing. One of these is hard-metal pneumoconiosis, commonly referred to as “cobalt lung.” It’s a form of pneumonia usually seen in people with long-term exposure to the airborne particulates caused by metal grinding.

Another is bronchiolitis obliterans, or “popcorn lung,” which is the disease you’re asking about. The nickname arises because the disease is linked to a butter-flavored chemical called diacetyl, which was once used in the manufacture of microwave popcorn. This rare form of bronchitis causes the tiny airways within the lungs, known as bronchioles, to become inflamed. This results in tissue damage, including scarring, which thickens and blocks the airways.

Symptoms of popcorn lung include a persistent dry cough and shortness of breath, which become more pronounced during exertion.

Additional symptoms can include fatigue and wheezing that are not associated with asthma or illness. Diagnosis often begins with tests to determine lung function. Since chest X-rays can often appear normal in the early stages of the disease, high-resolution imaging tests such as a chest CT scan are often used. There is no cure at this time, so treatment focuses on managing symptoms to slow the progression of the disease. Depending on the individual case, this can include medication to lessen the body’s immune response and to ease inflammation. Antibiotics, cough suppressants and supplemental oxygen may also be used. In extreme cases, a lung transplant may be necessary.

Fortunately, there is also good news. Statistics show that the pace of the vaping illness outbreak is slowing. In addition, research now points to black-market vape products as a source of many of the lung injuries.

Still, very little is known about the long-term effects of any kind of vaping. Unless they’re using legitimate products in order to stop smoking, we recommend that our patients don’t vape. The risks of this as a recreational practice are just too great.