History, Assessment and Testing
With occupational asthma a pattern usually develops that can show how symptoms are caused by something in the workplace.
This pattern may look like:
- Wheezing at the start of the work week can happen sometimes within minutes of starting to work or with in one to two hours
- Relief from wheezing after stopping work or after returning home
- The symptoms get worse or increase as the work week goes on, usually with relief over the weekends or after days off
- Sometimes symptoms that occur while at work may be worse late in the evening or may wake you up from your sleep during the night.
- Sometimes it is hard for a doctor to confirm this diagnosis because they only see the worker away from the work place, such as days of f or after some time of f work. Because symptoms are often less or gone the physician does not have proof to support a diagnosis of occupational asthma. It is very important to tell you doctor where you work, or if you think your asthma might be related to work
Assessing the Work Environment
It is important to take a detailed work history of the workers present and past employment. Sometimes it is hard to pin point the exact chemical or material that is causing the problem so many questions should be asked about what the workers uses at work as well as the workplace in general. Sometimes an occupational hygienist may visit the workplace to help identify hazardous chemicals. It is also important to see if any other workers are having the same symptoms. Symptoms among several workers in a specific area or may give a clue as to what is causing the problem.
Lung Function Testing
There are a couple of test used to help diagnose occupational asthma.
Pulmonary Function Test (PFT's)
Sometimes called a breathing test, this lung test is used to see how well your lungs are working. This test is done by taking a big breath and blowing forcefully and as quickly as possible into a device called a spirometer. The test can be used to show any lung disease or trouble in breathing that may have been caused by something in the workplace. This test can catch a problem that you might not be aware of yet if you are symptom free. It may also show a problem that cannot yet be seen on a chest x-ray. Results that reflect changes caused by the workplace should happen before a shift, after a shift or at the start or end of the work week.
Peak Flow Measurements
You might need to test lung function during a normal working day. The doctor will give you a small, machine called a peak flow meter and show you how to blow in it and record your results. The best of three readings is usually taken and noted ever y two hours between working and sleeping. It may take several days to establish a pattern.