Occupational asthma is a type of asthma that arises or worsens by exposure to certain substances at the workplace, such as fumes, chemicals, gases, or other substances.

Early and proper diagnosis can help effectively treat occupational asthma, while late diagnosis and long-term exposure can cause permanent changes to the lungs.

This article discusses the triggers and types of asthma, specifically occupational asthma, its symptoms, and its causes. We also examine the diagnosis, treatment, and prevention of the condition.

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Asthma is a chronic disease that leads to inflammation and narrowing of the airways. The condition affects 15—20% of people in developed countries and 2–4% in less developed countries.

Several different types of asthma relate to exercise, allergies, seasons, or other environmental factors.

Read more about the types of asthma.


Some common asthma triggers include:

  • environmental allergens
  • viral respiratory tract infections
  • tobacco smoke
  • use of beta-blockers
  • chemical fumes
  • emotional factors such as stress

The Global Strategy for Asthma Prevention and Management (GINA) attributes 5–20% of cases of adult-onset asthma to occupational asthma.

Exposure to allergens or sensitizing agents at work induces or aggravates symptoms of occupational asthma. Therefore, it is different from the other types since it usually only occurs while a person is working.


The symptoms of occupational asthma are similar to other types of asthma and depend on how long and how often the exposure occurs.

Some common symptoms of occupational asthma include:

The symptoms often go away during weekends and vacations but reappear on return to work. In the case of long-term exposure, the symptoms may continue even after no exposure. These are part of the essential screening questions to diagnose occupational asthma.

Complications can arise in the case of continuous exposure to the substance responsible for the condition or if treatment is not received. Longer exposure can lead to a worsening of symptoms, making them difficult to treat.

According to the American Academy of Allergy Asthma and Immunology, permanent damage to the lungs can occur in certain cases of acute occupational asthma.

People must visit a doctor immediately if they have any signs of breathing problems that indicate asthma. Emergency treatment is necessary in the following cases:

  • worsening of wheezing
  • shortness of breath even while doing minimal activity
  • no improvement in asthma symptoms even after using medications

Identification of more than 400 agents that can lead to occupational asthma has occurred, and the list keeps growing.

The table below includes the most common irritants and allergens that can cause occupational asthma and its associated profession.

chemicals adhesive handlers, painters, and chemical manufacturers
cereals bakers and farmers
platinum, nickel, cobaltmetalworkers
dyes textile workers
wood dustcarpenters, forest workers, and sawmill workers
drugs, latex, and enzymeshealthcare and pharmaceutical professionals
animal substances veterinarians
plants and fungiforest workers and farmers

Some of the ways to prevent occupational asthma include:

  • pre-employment screening to reduce the number of susceptible persons among workers
  • eliminating the irritant or allergen
  • reducing the exposure to the irritant or allergen
  • using of personal protective equipment (PPE) such as respirators
  • routine medical screening to identify any initial symptoms of asthma in workers
  • relocating the exposed worker on confirmation of the diagnosis
  • using pharmaceutical medications to control the disease

Tests to diagnose occupational asthma also help confirm other types of asthma. The tests that help to diagnose occupational asthma include:

  • Physical examination: The first step of diagnosis is a physical examination where a doctor will look into the throat, eyes, nose, chest, and lungs for any signs of asthma or obstructed airway.
  • Spirometry test: This is a lung function test where a person will need to take a deep breath and blow air out into the spirometer forcibly. The spirometer measures the speed at which the air flows out from the lungs.
  • Peak flow measurement: This test involves a peak flow meter that measures the movement of air out of the lungs and is very sensitive to changes in the airways. It can help diagnose asthma even before the onset of symptoms.
  • Fractional exhaled nitric oxide (FeNO) test: The FeNO test measures the amount of nitric oxide present in the breath, which can determine the presence of inflammation in the airways, which might indicate asthma.
  • Allergy test: A doctor may use a skin prick or blood test to detect any allergic responses.
  • Challenge test: This test can determine if a small number of suspected chemicals can trigger a reaction. Determination of the lung function before and after exposure to the chemical helps identify if it can affect the ability to breathe.
  • Chest X-ray: A doctor might recommend a chest X-ray to determine the lung condition.

Read more about testing for asthma.

The most important step in treating asthma is stopping or reducing exposure to triggers causing symptoms. A person should work with their doctor to develop a personal asthma control plan.

Doctors often treat asthma with two general types of medication: quick relief and long-term control.

Some of the current treatment options are:

  • short-acting inhalers that help to keep the airways open
  • long-acting bronchodilators that keep airways open for longer periods of time
  • anti-inflammatory medications such as inhaled or oral corticosteroids help to reduce inflammation
  • antibiotics that can help to treat bacterial pneumonia or bronchitis
  • a combination of bronchodilators and inhaled corticosteroids

The two common delivery devices used to take asthma medications are inhalers and nebulizers. They allow the medicines to directly go to the lungs. However, intake of a few medicines is also in pill form, injectable form, or infusion form.

Learn more about asthma treatments.

Adults working in a particular job and exposed to certain triggering substances can give rise to occupational asthma.

The symptoms, diagnosis, and treatment of occupational asthma are similar to the other types of asthma.

To prevent occupational asthma from causing long-term lung problems, doctors may recommend using PPE to avoid exposure to irritants, relocation of exposed workers, or complete elimination of exposure.