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- Patient Comments: Occupational Asthma - Causes and Risks
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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 are symptoms and signs of occupational asthma?
Symptoms usually begin with wheezing, shortness of breath, and chest tightness weeks to years after workplace exposure. Often, runny nose (rhinorrhea) and inflammation of the lining around the eyes (conjunctivitis) are present as well and may even occur before any wheezing or shortness of breath develops. Occasionally cough with or without phlegm (sputum) production may be present as well.
Initially, patients may notice that their symptoms are worse at work and better during weekends or holidays away from work. If no action is taken, patients may develop constant symptoms.
The latency period between the time of exposure to the time of onset of symptoms is highly variable. The latency period for occupational asthma caused by low-molecular weight compounds seems to be shorter than that for high-molecular weight compounds. The latency period for high-molecular weight compounds is often several years.
A severe form of irritant-induced occupational asthma is called reactive airways dysfunction syndrome (RADS). This is a condition where the patient suffers a single exposure to a very high concentration of a noxious chemical, usually a gas. A person suffering from RADS will have shortness of breath and chest tightness severe enough to seek medical attention within 24 hours of the exposure. After recovery from the initial massive exposure, the patient will have airways that remain excessively reactive, or "twitchy," from stimulation by the agent that caused the initial symptoms or other agents. Almost all patients with RADS will have excessively responsive airways for three months, and 50%-60% will still have excessively responsive airways even 18 months later.
How do health-care professionals diagnose occupational asthma?
A thorough history and physical examination is performed for any patient in whom occupational asthma is suspected. Important questions include the type of symptoms, duration of symptoms, timing of symptoms, and factors that make symptoms better or worse. The characteristics of the workplace, including any inhalational exposures, is evaluated. Material Safety Data Sheets (MSDS) may contain helpful information about the workplace. These will generally be on site in your workplace.
A test to measure the flow of air in and out of your lungs, called spirometry or a pulmonary function test, may be performed. This test is used to define the diagnosis of asthma. This test may involve giving an inhaled medicine called a bronchodilator to relax or dilate the airways. Alternatively, the test may involve administering a medicine to see how excessively responsive, or twitchy, the airways are (bronchoprovocation test).
A peak expiratory flow meter may be recommended to measure airflow during exhalation both at home and at work. Typically, results are recorded daily for a few weeks to see if there is a difference in airflow at work and away from work. Skin tests can be done, where an agent thought to cause your symptoms is introduced below the first layer of skin with a small needle to see if this agent triggers an inflammatory response. However, skin tests are not available for most agents that cause occupational asthma.