Occupational Asthma

1 What is Occupational Asthma?

Occupational asthma refers to the work-related lung condition caused by exposure to substances like

  • chemicals,
  • fumes,
  • dust in the work place.

Symptoms of occupational asthma resemble that of other types of asthma, like

These symptoms are generally worse on the days of work when compared to others. It generally helps to differentiate occupational asthma from other types.

Reducing exposure to the triggers at work place is the best way to control the symptoms.

Continued exposure to the triggers makes treatment difficult and result in life-long asthma. 

2 Symptoms

Symptoms of occupational asthma resemble that of other types:

Some not-so-common symptoms of the condition include:

Other symptoms depend on the trigger of asthma and the duration of exposure to the substance.

Symptoms of occupational asthma gets worse on working days and resolves on weekends or vacations. The symptoms may then return with the start of work week.

Some of the symptoms may persist even when one is off from work. The symptoms may start immediately after the exposure to the trigger or after a period of exposure to the substance.

Longer duration of exposure increases the chance of persistent symptoms of asthma.

3 Causes

Many substances in workplaces are known to cause occupational asthma.

These substances include:

  • Proteins, dander, hair, scales, fur, and saliva form animal-related workplaces
  • Varnishes, adhesives, laminates, and resins used in paint manufacturing
  • Chemicals used in insulation, packaging, and upholstery work
  • Enzymes used in detergents and flour conditioners
  • Platinum, chromium, and nickel sulfate
  • Proteins found in natural substances like latex, cereals, flour, flax, hemp, rye, and wheat
  • Chlorine gas and sulfur dioxide smoke

Symptoms of asthma are caused by inflammation of the airways. Exposure to the triggers induces the symptoms of asthma.

Risk of occupational asthma is more with:

  • History of allergies and asthma
  • Family history of asthma
  • Exposure to triggers in work place
  • Smoking

Certain occupations are considered to be high-risk occupations for developing asthma.

This includes:

  • adhesive handlers,
  • carpet makers,
  • metal workers,
  • carpenters,
  • hairdressers,
  • healthcare workers,
  • seafood processors,
  • painters,
  • insulation installers,
  • textile workers,
  • foam industry workers,
  • shellac handlers.

4 Making a Diagnosis

Diagnosis of occupational asthma is based on lung function test and allergy test.

Spirometry measures the amount of air exhaled after a deep breath. This indicates the narrowing of airways.

Peak flow meter is a lung function test that evaluates how hard one can exhale. Low peak flow readings indicate abnormality in the function of lungs.

Lung function test is usually taken by dilating the airways using a bronchodilator. High levels of nitric oxide in the breath also indicates asthma, measured by nitric oxide test.

Reaction to a specific test is assessed by allergy test and challenge test. In allergy test, small amounts of the trigger is pinched into the skin to check for any allergic reaction.

This test is commonly used for animal and plant proteins like dander, latex, and mites. In a challenge test, small amount of the suspected material is inhaled to see the reaction.

Lung function test is conducted before and after the challenge test to see the effect of the substance in breathing.

5 Treatment

Treatment strategy for occupational asthma involves preventing symptoms and treating asthma attack. Medications prescribed for occupational asthma depends on:

  • the trigger,
  • symptoms,
  • age of the person.

Preventive medications

Reduce the inflammation of the airways. They have to be taken every day for a long term to prevent flare ups, even when exposed to asthma trigger.

Corticosteroids like:

  • fluticasone,
  • budesonide,
  • ciclesonide

are used as inhalers for long-term. Leukotriene modifiers are oral medications for long-term protection from symptoms.

  • Montelukast,
  • zafirlukast,
  • zileuton

are commonly prescribed leukotriene modifiers.

Combination inhalers contain a long-acting beta agonists (LABA) and inhaled corticosteroids, and is recommended in cases that do not respond to other medications.

Theophylline is a medication used to keep the muscles of airways relaxed and to help in making breathing easier.

Quick-relief medications, or rescue medications

Open up the narrow passage way for improving breathing. It is prescribed during an asthma attack. Short-acting beta agonists like albuterol and levalbuterol helps to open up the airway within minutes, and relieve the symptoms soon.

Ipratropium is another quick-relief medication that helps to relax the airways and to improve breathing.

Oral and intravenous corticosteroids are also used as rescue medications to alleviate inflammation of airways.

If the asthma is induced by allergy, oral and nasal sprays of antihistamines and decongestants are prescribed. To reduce the immune reaction to the triggers, sensitivity of the system is reduced by regular exposure to small doses of the substance.

It is usually given as shots once a week for few months, and then gradually reduced to once a month for few years.

Omalizumab is recommended for allergies and asthma that does not respond to any of the conventional treatment methods.

6 Prevention

Occupational asthma attacks can be prevented or reduced by:

  • Quitting smoking
  • Avoiding triggers like chemicals and gases
  • Reducing allergens in house

Companies involved in high-risk professions for asthma attacks train the employees to safely handle the substance and how to respond to an emergency.

Protective gears are a must in the workplace to avoid the exposure to the triggers.

7 Alternative and Homeopathic Remedies

Some common homeopathic remedies suggested in the treatment of occupational asthma include:

  • antimonium tartaricum,
  • cuprum metallicum,
  • sambucus nigra,
  • bryonia,
  • ribes nigrum,
  • ipeca,
  • kalium carbonica,
  • cactus grandiflorus.

A number of other treatment methods are also suggested in the treatment of occupational asthma, but lack supportive scientific evidence for the efficacy and safety.

  • Buteyko method,
  • Papworth method,
  • breathing exercises in yoga

are considered to be effective in controlling breathing pattern.

Acupuncture and traditional Chinese medicines are also being tried in controlling symptoms of this asthma.

Supplements of omega-3-fatty acids, vitamin C, and bitter orange is suggested in the treatment of asthma symptoms. 

8 Lifestyle and Coping

Lifestyle modifications are necessary in order to cope with occupational asthma.

Once diagnosed with this type of asthma, talk to your physician to develop an effective treatment plan.

One should also employ methods to avoid exposure to the triggers at the work place.

Follow the treatment plan diligently to avoid long-term complications. 

9 Risks and Complications

There are several risks and complications associated with occupational asthma.

Increased exposure to the triggers worsens symptoms of asthma.

It may lead to permanent lung damage and life-time asthma in some people. 

10 Related Clinical Trials