Popcorn lung is the common name for bronchiolitis obliterans (BO). It is a rare, but serious and irreversible lung disease. It can be caused by inhalation of certain chemicals, including diacetyl. This condition first became known to the public when workers in a popcorn factory developed it: they inhaled diacetyl while making the buttery flavor for the popcorn.

Causes

Popcorn lung can stem from multiple causes, including respiratory infections, connective tissue disorders, transplant rejection, and exposure to toxic chemicals. Of these, chemicals such as diacetyl are common triggers.

Diacetyl is a chemical commonly used to add a buttery flavor to microwave popcorn. When breathed in, it can damage the smallest airways in the lungs (bronchioles), causing inflammation and scarring. This can lead to narrowing and obstruction of the airways, making breathing difficult. Other chemicals—such as acetaldehyde, acrolein, and formaldehyde—can also cause such lung damage when inhaled.

Symptoms

Common symptoms of popcorn lung are a dry cough, wheezing, shortness of breath, and fatigue.

These symptoms typically don’t appear right away—they may develop gradually 2 to 8 weeks after infection or toxic exposure. In the early stages, they can sometimes be mistaken for a cold. Unlike a cold, though, popcorn lung does not improve; it worsens over time.

In some cases, however, severe symptoms may also appear suddenly, rather than gradually.

Diagnosis

Popcorn lung is often suspected based on symptoms, but this can be challenging: its symptoms overlap with other lung diseases such as the flu, pneumoconiosis, or chronic obstructive pulmonary disease (COPD). If a patient has a history of exposure to diacetyl or other toxic chemicals, though, a doctor may suspect popcorn lung.

A number of tests are usually needed to confirm the diagnosis, including lung function tests, chest X-rays, and CT scans. If necessary, a lung biopsy may also be performed to confirm it.

Treatment

There is currently no cure for popcorn lung, but treatment can help manage symptoms and slow further progression. This may include bronchodilators, corticosteroids, or immunosuppressive drugs. Oxygen therapy is often needed when breathing is difficult (a condition called hypoxemia). Anti-infectives may be prescribed in cases of infection. In severe cases, a lung transplant may be necessary.

The disease is irreversible, and the prognosis is often poor. That is why early detection is essential. If it is caused by inhaling diacetyl or other toxic chemicals, removing exposure to these substances is also critical.

Vaping

The link between vaping and popcorn lung is not yet fully understood. There is persistent concern, however, that flavored e-cigarettes may expose users to toxic chemicals. Studies have found diacetyl, acetaldehyde, acrolein, formaldehyde, and diethylene glycol, among others, in e-cigarettes. When inhaled over time, these chemicals can cause a variety of potential lung damage.

The long-term consequences of vaping are mostly unclear, and more research is needed to fully understand the risks of e-cigarette use. Still, some studies suggest that vaping may increase the risk of developing lung illness—including popcorn lung. It is important to recognize these potential risks and take steps to reduce exposure to potentially toxic chemicals.

Summary

Popcorn lung is a serious, incurable disease caused by inhaling certain chemicals like diacetyl. The link between vaping and the disease remains unclear, but early detection and avoiding exposure to the harmful chemicals causing it are essential. If you develop symptoms of popcorn lung or other lung diseases, seek early medical attention and discuss your concerns with your healthcare provider.