Occupational asthma is a lung disorder in which substances found in the workplace cause the airways of the lungs to swell and narrow, leading to attacks of wheezing, shortness of breath, chest tightness, and coughing.
Asthma - occupational exposure; Irritant-induced reactive airways disease
Many substances in the workplace can cause occupational asthma. The most common triggers are wood dust, grain dust, animal dander, fungi, or other chemicals (especially diisocyanates).
Though the actual rate of occurrence of occupational asthma is unknown, it is suspected to cause 2 - 20% of all asthma cases in industrialized nations.
The following workers are at higher risk:
Symptoms are usually due to swelling of the airways and spasms of the muscles lining the airways. This reduces the amount of air that can pass through, and can lead to wheezing sounds. See also: Asthma
Symptoms usually occur shortly after you are exposed to the substance, and often improve or go away when you leave work. Some people may not have symptoms until 12 or more hours after being exposed to the allergen.
Symptoms usually get worse toward the end of the work week and may (but not always) go away on weekends or vacations.
In general, symptoms include:
The health care provider will perform a physical exam and ask questions about your medical history. Your symptoms may have a pattern of getting worse with a certain workplace environment or substance.
The health care provider may hear wheezing when listening to the chest with a stethoscope.
The following tests may be used to diagnose this condition:
Avoiding exposure to the substance that is causing your asthma is the best treatment.
Asthma medicines (almost always inhalers) may help you manage your symptoms. Talk to your doctor about these medicines.
Occupational asthma may keep getting worse if you continue to be exposed to the substance that is causing the problem, even if medicines improve your symptoms. You may need to change jobs.
Sometimes, symptoms may continue even when the substance is removed.
In general, the outcome for people with asthma is good. However, symptoms may continue for years after you are no longer exposed in the workplace.
Call your health care provider if you have symptoms of asthma.
Chan-Yeung M, Malo JL. Asthma in the workplace and occupational asthma. In: Mason RJ, Broaddus VC, Martin TR, et al. Murray & Nadel's Textbook of Respiratory Medicine. 5th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 64.
Cowl CT. Occupational asthma: review of assessment, treatment, and compensation. Chest. 2011;139(3):674-681.