Occupational asthma

Occupational asthma develops when a person is exposed to a particular inhaled substance in the workplace. The term refers to new cases of asthma, but workplace exposure to substances that cause airway irritation or inflammation can make asthma worse in people who already have the condition. About 10% of adult asthma is classified as occupational asthma.¹

Occupational asthma is the most common form of work-related lung disease in many countries. When a person develops asthma as an adult, occupational exposure is a likely cause.

There are some things that may cause occupational asthma and certain professions in which people might be exposed to them. These include:

• Flour dust (bakers, millers).
• Wood dust (carpenters, joiners, sawmill workers).
• Plastics (plastics workers, motor vehicle repairers, foundry workers).
• Solder fumes (electronics workers).
• Animal dander or urine (animal handlers in research laboratories, scientists, food processors).
• Chemicals used in the health care industry to sterilize equipment (health care workers).
• Latex.

People who have occupational asthma usually have symptoms during the workweek, such as coughing, wheezing, and chest tightness. These may develop hours after leaving the workplace. Symptoms generally improve during weekends and vacations.

The diagnosis of occupational asthma requires detailed documentation of exposure to irritants or allergens in the workplace and evidence that these substances are causing symptoms. In a test called specific inhalation challenge, you are exposed to a small amount of a possible workplace irritant or allergen. Lung function is then measured to find out whether the substance is the cause of symptoms.

Treatment of occupational asthma consists of:

• Trying to decrease your exposure to possible triggers. You may try to improve the ventilation in your work area, or you might wear a type of breathing mask called a respirator.
• Taking medications to treat your symptoms. Medications used to treat occupational asthma are similar to those used to treat other types of asthma, including inhaled corticosteroids to reduce inflammation and quick-relief medications (such as bronchodilators) to help you breathe during an asthma attack.

You may need to change your job if your symptoms do not improve even when you avoid possible triggers and take medications. Talk with your health professional or asthma specialist before changing your job.

Citations

1. Tarlo SM, Liss GM (2003). Occupational asthma: An approach to diagnosis and management. Canadian Medical Association Journal, 168(7): 867–871.