Diagnosing occupational asthma is similar to diagnosing other types of asthma. However, your doctor will also try to identify whether a workplace substance is causing your symptoms and what it may be.
An asthma diagnosis needs to be confirmed with lung (pulmonary) function tests and an allergy skin prick test. Your doctor may order blood tests, X-rays or other tests to rule out a cause other than occupational asthma.
Testing your lung function
Your doctor may ask you to perform lung function tests. These include:
Spirometry. This noninvasive test, which measures how well you breathe, is the preferred test for diagnosing asthma. During this 10- to 15-minute test, you take deep breaths and forcefully exhale into a hose connected to a machine called a spirometer. If certain key measurements are below normal for a person of your age and sex, your airways may be blocked by inflammation — a key sign of asthma.
Your doctor has you inhale a bronchodilator drug used in asthma treatment, then retake the spirometry test. If your measurements improve significantly, it's likely you have asthma.
- Peak flow measurement. Your doctor may ask you to carry a small hand-held device that measures how fast you can force air out of your lungs (peak flow meter). The slower you are able to exhale, the worse your condition. You'll likely be asked to use your peak flow meter at selected intervals during working and nonworking hours. If your breathing improves significantly when you're away from work, you may have occupational asthma.
Tests for causes of occupational asthma
Your doctor may do tests to see whether you have a reaction to specific substances. These include:
- Allergy skin tests. Doctors will prick your skin with purified allergy extracts and observe your skin for signs of an allergic reaction. These tests can't be used to diagnose sensitivities to chemicals but may be useful in evaluating sensitivity to animal dander, mold, dust mites and latex.
- Challenge test. You inhale an aerosol containing a small amount of a suspected chemical to see if it triggers a reaction. Doctors test your lung function before and after the aerosol is given to see whether it affects your ability to breathe.
Avoiding the workplace substance that causes your symptoms is critical. However, once you become sensitive to a substance, tiny amounts may trigger asthma symptoms, even if you wear a mask or respirator.
The goal of treatment is to prevent symptoms and stop an asthma attack in progress. You may need medications for successful treatment. The same medication guidelines are used to treat both occupational and nonoccupational asthma.
The right medication for you depends on a number of things, including your age, symptoms, asthma triggers and what seems to work best to keep your asthma under control.
Long-term control medications.
- Inhaled corticosteroids. Inhaled corticosteroids reduce inflammation and have a relatively low risk of side effects.
- Leukotriene modifiers. These controller medications are alternatives to corticosteroids.
- Long-acting beta agonists (LABAs). LABAs open the airways and reduce inflammation. For asthma, LABAs generally should only be taken in combination with an inhaled corticosteroid.
- Combination inhalers. These medications contain an LABA and a corticosteroid.
Quick-relief, short-term medications.
- Short-acting beta agonists. These medications ease symptoms during an asthma attack.
- Oral and intravenous corticosteroids. These relieve airway inflammation for severe asthma. Long-term, they cause serious side effects.
If you find you need to use a quick-relief inhaler more often than your doctor recommends, you may need to adjust your long-term control medication.
Also, if your asthma is triggered or worsened by allergies, you may benefit from allergy treatment. Allergy treatments include oral and nasal spray antihistamines and decongestants.
While many people claim alternative remedies reduce asthma symptoms, in most cases more research is needed to see if they work and if they have possible side effects, especially in people with allergies and asthma. A number of alternative treatments have been tried for asthma, but there's no clear, proven benefit from treatments such as:
- Breathing techniques. These include structured breathing programs such as the Buteyko method, the Papworth method, lung-muscle training and yoga breathing exercises (pranayama). While these techniques may help improve quality of life, they have not proved to improve asthma symptoms.
- Acupuncture. This technique has roots in traditional Chinese medicine. It involves placing very thin needles at strategic points on your body. Acupuncture is safe and generally painless, but evidence for its use in asthma is inconclusive.
Preparing for your appointment
You're likely to start by seeing your primary doctor. Or you may start by seeing a doctor who specializes in asthma (allergist-immunologist or pulmonologist).
Here's some information to help you prepare for your appointment.
What you can do
- Be aware of any pre-appointment restrictions. When you make the appointment, ask if there's anything you need to do in advance. You may need to stop taking antihistamines if you're likely to have an allergy skin test.
- Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
- Note the timing of your asthma symptoms — for example, note if your symptoms are worse at work and get better when you're away from work.
- Make a list of all possible workplace lung irritants and anything else that seems to trigger your symptoms. You may want to take a look at the material safety data sheet (MSDS) for your work area, if there is one. Usually kept in a binder near your work area, this sheet lists toxic substances and irritants used on your job site. (Keep in mind, not all occupational asthma triggers are listed in the MSDS).
- Write down key personal information, including major stresses or recent life changes and changes in your job or workplace.
- Bring a list of all medications, vitamins or supplements you take.
- Bring a family member or friend along, if possible. Someone who accompanies you may remember information you missed or forgot.
- Write down questions to ask your doctor.
For occupational asthma, some basic questions to ask your doctor include:
- Is a workplace irritant a likely cause of my breathing problems or asthma flare-ups?
- Other than the most likely cause, what are other possible causes for my symptoms or condition?
- What tests do I need? Do these tests require any special preparation?
- Is my condition likely temporary or chronic?
- How do I treat occupational asthma? Do I have to quit my job?
- What are the alternatives to the primary approach you're suggesting?
- I have other health conditions. How can I best manage these conditions together?
- Are there restrictions that I need to follow?
- Should I see a specialist?
- Is there a generic alternative to the medicine you're prescribing?
- Are there brochures or other printed material I can take with me? What websites do you recommend?
Don't hesitate to ask other questions.
What to expect from your doctor
Your doctor is likely to ask you a number of questions, such as:
- When did you first notice your symptoms?
- How severe are your symptoms?
- Do you have breathing problems when you're away from work or only when you're on the job?
- Have your symptoms been continuous, or do they come and go?
- Have you been diagnosed with allergies or asthma?
- Are you exposed to fumes, gases, smoke, irritants, chemicals, or plant or animal substances at work? If so, how often and for how long?
- Do you work in unusual environmental conditions, such as extreme heat, cold or dryness?
- What, if anything, appears to improve your symptoms?
- What, if anything, appears to worsen your symptoms?
- Do allergies and asthma run in your family?