Occupational Asthma

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Introduction of occupational asthma:

Are you often getting sick at your job? Answer the following questions in yes and no. If the answer of any one is yes then you may be suffering from Occupational asthma:

  • Do you experience coughing, wheezing or shortness of breath at work?

  • Do you have itchy red eyes or running nose at work?

  • Does the problem goes when you are away from work and comes back when you return to work?

Occupational Asthma is the most common occupational lung disease in most part of the world. It is responsible for 2 % to 15 % of the asthma prevalence. The frequency varies widely between different occupations and within industry at different level of exposure.

Occupational asthma is a respiratory disease caused by the exposure to a trigger at the work place (be it dust, gases, vapors, fumes or chemicals). When inhaled these triggers irritate the airways and may cause Coughing, sneezing, chest tightness, pain in chest, difficulty in breathing. It may be associated with skin, eye and other allergies.

Types of Occupational asthma:

Generally two types of asthma attack occur:

  • Occupational asthma without latency

Asthma attack brought on immediately by exposure to extremely high levels of irritant gases such as ammonia, sulfur dioxide, chlorine. This is also known as Reactive Airways Dysfunction Syndrome (RADS)

  • Occupational asthma with latency (Long term sensitization)

Body develops an allergy from continuous exposure to a specific substance, sometimes over the period of months and years. Symptoms of OA occur when body develops allergic response to the substance 

Due to exposure to the trigger asthma attack is precipitated. The walls of the airways become inflamed and swollen. Lot of mucous is secreted blocking the airways. This makes it difficult for the air to be exhaled or pushed out of the lungs.

Substances causing Occupational Asthma:

Substances which cause Occupational Asthma are commonly known as triggers. At least 240 substances are known to cause Occupational asthma when inhaled. They are classified in 5 categories.

Respiratory irritants:
Like smoke, sulfur dioxide, chlorine gas, ammonia.
Grain flour and food allergens:
Like Grain dust and flours (like wheat & rye), proteins of cereal grains, sea food, egg processing, green coffee beans, castor beans, ispaghula.
Animal allergens & proteins:
These are found in hairs, furs, dander, scales, saliva and other body wastes like excreta.
Enzymes are used in pharmaceuticals, detergents, flour conditioners, etc.
1. Acid anhydrides, isocyanides, complex platinum salts, poly amines,
2. Reactive dyes, units manufacturing paints, varnishes, adhesives,
3. Laminates, soldering fluxes, resins used in soldering.

Chemical agents causing occupational asthma

Next page

Page- 1
Types of Occupational asthma
Page- 2
Substances causing Occupational Asthma
Industries at risk
Cigarette smoking & Occupational asthma
Page- 3
Page- 4
When to see a doctor
Diagnostic tests and evaluation
Page- 5
Patient education
Monitoring the asthma
Drug treatment

Last edited 16-09-2010