Summary about Disease
Occupational asthma is a type of asthma caused or worsened by breathing in certain substances at work. It is characterized by airflow limitation and airway hyperresponsiveness attributable to workplace exposures. This exposure leads to sensitization and inflammation of the airways, resulting in asthma symptoms.
Symptoms
Symptoms of occupational asthma are similar to those of regular asthma and may include:
Wheezing
Coughing
Shortness of breath
Chest tightness
Runny nose
Eye irritation
Nasal congestion Symptoms may worsen during work hours or in the evening after work and improve on weekends or vacations.
Causes
Occupational asthma is triggered by exposure to a variety of substances in the workplace. Common causative agents include:
Chemicals (isocyanates, anhydrides, epoxy resins)
Metals (platinum, nickel, chromium)
Wood dust
Grains and flours
Animal dander
Latex
Enzymes (used in detergents)
Paints
Soldering fumes
Medicine Used
The medications used to treat occupational asthma are the same as those used for other types of asthma and may include:
Inhaled Corticosteroids: To reduce inflammation in the airways (e.g., fluticasone, budesonide).
Long-Acting Beta-Agonists (LABAs): To relax airway muscles and improve breathing (e.g., salmeterol, formoterol). These are often combined with inhaled corticosteroids.
Short-Acting Beta-Agonists (SABAs): For quick relief of symptoms (e.g., albuterol).
Leukotriene Modifiers: To block the action of leukotrienes, substances that cause airway inflammation (e.g., montelukast).
Theophylline: A bronchodilator.
Biologics: For severe asthma, medications like omalizumab (anti-IgE) or dupilumab (anti-IL-4Rα) may be used.
Oral Corticosteroids: For short-term control of severe symptoms.
Is Communicable
No, occupational asthma is not communicable. It is caused by exposure to substances in the workplace and is not infectious.
Precautions
Preventative measures and precautions in the workplace include:
Ventilation: Improving ventilation systems to reduce airborne concentrations of harmful substances.
Engineering Controls: Using enclosed systems, local exhaust ventilation, and other methods to control exposure at the source.
Personal Protective Equipment (PPE): Wearing respirators, gloves, and protective clothing to minimize exposure.
Substitution: Replacing hazardous materials with safer alternatives.
Work Practices: Implementing safe work practices and training employees on proper handling of substances.
Medical Surveillance: Regular monitoring of employees at risk, including lung function testing and symptom questionnaires.
Early Detection: Identifying and addressing early symptoms to prevent progression of the disease.
How long does an outbreak last?
Occupational asthma isn't typically thought of as an "outbreak," rather as a chronic condition that develops over time with repeated exposure to a sensitizing substance. Once sensitized, symptoms can be triggered by even low-level exposures. Symptoms can persist as long as the individual is exposed to the trigger. Even after removing the trigger, symptoms may persist for weeks, months, or even years.
How is it diagnosed?
Diagnosis of occupational asthma involves:
Medical History: Detailed history of symptoms, work history, and potential exposures.
Physical Exam: A general assessment of lung function and overall health.
Pulmonary Function Tests (PFTs): Spirometry to measure airflow limitation and assess lung function. Bronchial provocation tests (methacholine challenge) may be used to assess airway hyperresponsiveness.
Allergy Testing: Skin prick tests or blood tests (specific IgE) to identify potential allergens.
Specific Inhalation Challenge (SIC): Controlled exposure to suspected agents under medical supervision to monitor for asthma symptoms and changes in lung function. This is the gold standard for diagnosing occupational asthma, but is not always performed due to safety concerns and availability.
Peak Flow Monitoring: Regular monitoring of peak expiratory flow (PEF) at work and away from work to identify patterns related to workplace exposures.
Timeline of Symptoms
The timeline of symptoms can vary:
Sensitization: Some individuals may become sensitized to a substance after a single, high-level exposure, while others may require months or years of lower-level exposure.
Latency Period: The time between initial exposure and the onset of symptoms can range from weeks to years.
Symptom Progression: Symptoms may initially be mild and intermittent, worsening over time with continued exposure.
Persistence After Exposure: Even after exposure ceases, symptoms may persist for weeks, months, or years, particularly if the individual has had prolonged or severe exposure. Some may experience irreversible airway damage.
Important Considerations
Early Diagnosis is Key: The earlier occupational asthma is diagnosed and exposure is stopped, the better the prognosis.
Removal from Exposure: The most important step in managing occupational asthma is complete removal from the causative agent in the workplace.
Legal and Workers' Compensation: Individuals with occupational asthma may be eligible for workers' compensation benefits.
Job Modification/Change: Affected individuals may need to modify their job duties or change jobs to avoid further exposure.
Co-morbidities: Other respiratory conditions, such as rhinitis or sinusitis, can worsen occupational asthma symptoms.
Patient Education: Educating patients about their condition, triggers, and management strategies is essential.