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- Occupational asthma facts
- What is occupational asthma?
- What causes occupational asthma?
- What are risk factors for occupational asthma?
- What are symptoms and signs of occupational asthma?
- How do health-care professionals diagnose occupational asthma?
- What is the treatment for occupational asthma?
- What are complications of occupational asthma?
- Is it possible to prevent occupational asthma?
- Where can a person find more information about occupational asthma?
Quick GuideAsthma Attack Signs, Treatments, and Prevention
What causes occupational asthma?
Occupational asthma is caused by exposure to particular inhaled chemicals in the workplace that cause the airways to become excessively reactive.
There are many agents that can cause occupational asthma. Inhalations of isocyanates, cereal dust, or flour are currently the most common causes of occupational asthma. Agents that cause occupational asthma are usually divided into two different groups: smaller molecules (low molecular weight chemicals), such as isocyanates used in rubber manufacturing, and larger molecules, typically organic substances such as flour. You can find lists of known agents at http://www.hse.gov.uk/asthma/substances.htm.
What are risk factors for occupational asthma?
A patient's individual characteristics, as well as other factors in the workplace environment play a role in the development of occupational asthma. One of the main risk factors for occupational asthma is atopy. Atopy is a syndrome characterized by sensitivity to allergens that predisposes an individual to develop occupational asthma. People with atopy often have seasonal allergies or hay fever (allergic rhinitis), allergic skin rashes (eczema), and food allergies. An important risk factor for occupational asthma, which fortunately can be eliminated, is cigarette smoking. Scientists have also discovered specific genes involved with the immune system that may be associated with a person's risk of developing occupational asthma in response to specific agents, such as isocyanates and dust from western red cedar trees. However, there is no role for this type of genetic testing in routine clinical practice.
Although the intensity of exposure is important in the development of occupational asthma, it is less clear if it is the amount of the agent, duration of exposure, or frequency of exposures that represents the most important factor. Therefore, for most agents, it is difficult to determine what concentration of agent in the air is considered "safe."