What Are The First Symptoms Of Occupational Asthma & How Do You Test For It?

Occupational asthma is a type of asthma triggered only in the workplace when the body reacts against a specific substance in the workplace. It is marked by the symptoms similar to other forms of asthma, such as wheezing, cough, tightness in the chest, and shortness of breath. It often gets better when the patient is away from the workplace at the weekends and holidays. In some cases, the previous history of asthma is triggered by specific substances in the workplace in a more severe form.

What Are The First Symptoms Of Occupational Asthma?

Occupational asthma is a type of lung disease characterized by reversible narrowing of the windpipes due to exposure to a particular substance in the workplace. It is represented by shortness of breath, wheezing, chest tightness, and cough. Previously diagnosed asthma that deteriorates at work is termed as work-aggravated asthma.(1)

Occupational asthma symptoms are quite similar to other types of asthma. Its first symptoms may include wheezing, sometimes only at night, coughing, shortness of breath, and tightness in the chest. Initially, these symptoms are felt worse at work and usually get ameliorated during weekends or holidays away from the workplace. If it is left untreated or the workplace is not changed, the patient may develop constant symptoms of asthma.(2) Other possible signs and symptoms may also appear as runny nose, nasal congestion, eye irritation and tearing(2)

How Do You Test For Occupational Asthma?

Occupational asthma is diagnosed, similar to other types of asthma. However, it is necessary to identify the workplace substance, which is triggering the symptoms. It needs to be confirmed with lung (pulmonary) function tests and an allergy skin prick test to detect the causative substance. Other tests involve blood tests, X-rays, or other tests to rule out other causes of asthma, excluding occupational asthma.(3)

Lung Function Tests Include:

Spirometry- It is a noninvasive test used to measure the breathing capacity of a person. It is the preferred test that can diagnose asthma. It is the test performed for 10 to 15 minutes, in which the patient is asked to take deep breaths and exhale into a tube connected to a machine called a spirometer. If specific vital measurements are lower than normal levels of a certain age and sex, it is confirmed that the windpipes are blocked by inflammation, diagnosing asthma. After this, the patient is asked to inhale a bronchodilator drug used in asthma treatment; the test is repeated. If the measurements improve significantly, asthma is confirmed.(3)

Peak Flow Measurement- It is a test in which a small hand-held device is used to measure the pace at which the patient can exhale air (peak flow meter). Slower exhalation of the air signifies the worse condition of the patient. It is repeated many times at selected intervals during working and nonworking hours. If it is found that the breathing improves significantly when the patient is away from work, occupational asthma is diagnosed.(3)

Tests That Can Reveal The Causes Of Occupational Asthma:

Allergy Skin Tests- In this test, the skin is pricked with purified allergy extracts, and signs of an allergic reaction are observed. These tests cannot detect the sensitivities to chemicals but may help in the evaluation of sensitivity to animal dander, dust mites, mold, and latex.(3)

Challenge Test- the patient is asked to inhale a small amount of an aerosol containing a suspected chemical to observe a reaction. Doctors perform the lung function test before and after the aerosol is given to see the patient’s ability to breathe.(3)


The first symptoms of occupational asthma are represented by wheezing, shortness of breath, cough, and tightness in the chest felt in the workplace. It can be diagnosed by lung function test, allergy skin prick test, blood test, x-rays, and challenge test.


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