Popcorn lung, technically termed bronchiolitis obliterans, is a condition that is caused by scarring of the tissues inside the lungs. When it is caused by an environmental irritant such as the steam from popcorn production, then the patient requires immediate removal from the irritant. Popcorn lung is not reversible, but steroid treatments can often help relieve some of the symptoms such as breathlessness. Serious cases may require medication to suppress the inflammation caused by the lung damage, and some people may need lung transplants.
Normally, lungs are designed to take in mostly clean air, and when a person inhales air with pollution in it, or air with a concentration of certain chemicals, then the bronchioles of the lungs can become damaged. Bronchioles are little channels that air need to pass through to be absorbed by the body, and waste gases released by the body. Bronchiolitis obliterans is a disease that has a variety of causes, one of which is a chemical called diacetyl, which is used in some popcorn factories.
Workers in popcorn factories who use diacetyl as a butter-like flavoring can inhale the chemical over time. This constant exposure can cause bronchiolitis obliterans, which typically gets worse the more exposure the worker gets. The chemical scars the inside of the lungs permanently, and the condition has no cure, as of 2011.
As popcorn lung is a disease characterized by progressive damage to lung tissue over time, early detection of the condition is important for treatment. Less severely affected people can sometimes see benefits from steroid treatment, which reduces inflammation in the bronchioles and allows more air to pass through. Those with severe disease may not become better with simple steroids, and instead stronger drugs may be required, which block the immune response from creating inflammation and scarring. A disadvantage to the immune suppressant drugs is that the patient is at higher risk of developing infections than if on the steroids.
Lung transplants are a radical treatment for cases of popcorn lung that have progressed too far to be improved by steroids or immune suppressants. Medical attention is necessary for all cases of popcorn lung, as without treatment, the symptoms of the condition only show a slight improvement over time, and never disappear completely. As well as popcorn lung, diacetyl exposure can also produce asthma, or aggravate existing asthma, so workers who come into contact with diacetyl regularly should inform their doctor of their occupational exposure.