Occupational Asthma: How To Prevent

Introduction

Occupational asthma is asthma caused by or worsened by exposure to substances in the workplace. Many substances in the workplace can cause occupational asthma. The frequency of occupational asthma is not known but under-reporting is likely. Occupational asthma should be correctly diagnosed early so that workers can be protected or removed from the exposure before permanent lungs damage has occurred.

Prevention of occupational asthma

Three main components of preventive measures :

1. Primary prevention
   • Aims to prevent the onset of disease, often by reducing or eliminating exposure to the trigger agents in the workplace. This is the most effective means of control to prevent exposure altogether by substituting the trigger agent with a less harmful material via engineering and hygiene measures.
   • Respiratory protective equipment e.g. face mask has a role in situations where control at source is not feasible. It can only offer protection when it is worn properly, removed safely, replaced and maintained regularly.
2. Secondary prevention
   Periodic health surveillance for occupational asthma aims to detect disease at an early and reversible stage to improved income. Methods commonly used in surveillance to identify cases of occupational asthma are respiratory questionnaire, spirometry and identification of specific IgE by serology and skin prick test.
3. Tertiary prevention
   Tertiary prevention aims to prevent worsening symptoms by early recognition of occupational asthma and early removal from exposure and worker should be treated as an identified case of occupational asthma.

Treatment

The main aim of management is to identify the cause and remove the worker from exposure if possible. Preventing asthma symptoms by reducing exposure to the triggers at work is the most important step the worker can take to reduce the occurrence of occupational asthma. It is also important to use appropriate asthma medication to prevent and control symptoms.

Avoiding Exposure

Avoiding exposure to the substance that is causing the occupational asthma is the best treatment. Strategies include :

• Changing jobs.
• If in a particular job, exposure to asthma triggers is unavoidable, the employers have to assist the employee to find a more suitable workplace where there is less exposure to the substance.
• Using a respiratory device to protect or reduce the exposure.

Medications

Asthma medicines (especially inhalers) may help the patient to manage their symptoms. These include :

• Asthma reliever drugs – help to relax the muscles of the airways and to improve the acute symptoms.
• Asthma controller drugs – have to be taken every day to prevent asthmatic attack

Summary

In general, the outcome for workers with occupational asthma is good with early diagnosis and early avoidance of further exposure. It offers the best chance for complete recovery. However, occupational asthma may get worse if the workers continue to be exposed to the substance that is causing the asthmatic attack, even if the medicines may help to improve the symptoms.