Overview
Occupational asthma induced by sensitizers occurs when workers are exposed to specific chemicals in the workplace, leading to respiratory symptoms and airway inflammation characteristic of asthma. Common sensitizers include those found in plastic compounds such as polyvinyl chloride, polystyrene, and acrylonitrile-butadiene-styrene 1.Diagnosis
Clinical history: Exposure to known sensitizers in the workplace is crucial 1.
Pulmonary function tests: Spirometry showing variable airflow obstruction, often with reversibility 1.
Specific inhalation challenge: Gold standard for diagnosis, though not always feasible 1.
Serum specific IgE testing: Useful for confirming sensitization to specific agents 1.
Bronchial provocation tests: Indicate airway hyperresponsiveness 1.
Environmental monitoring: Confirm exposure levels and types of sensitizers 1.
Differential diagnosis: Rule out other causes of occupational respiratory disease 1.Management
Remove exposure: Primary intervention to prevent further sensitization and progression 1.
Inhaled corticosteroids: First-line pharmacological treatment to control inflammation (e.g., fluticasone 500-1000 mcg bid) 1.
Long-acting beta-agonists (LABAs): Add-on therapy to improve symptom control (e.g., salmeterol 50 mcg bid) 1.
Systemic corticosteroids: For severe exacerbations (e.g., prednisolone 40-60 mg/day for short courses) 1.
Leukotriene receptor antagonists: Alternative or adjunctive therapy (e.g., montelukast 10 mg/day) 1.
Non-pharmacological support: Pulmonary rehabilitation and patient education 1.Special Populations
Pregnancy: Management focuses on minimizing exposure and using safer medications; inhaled corticosteroids are generally considered safe 1.
Pediatrics: Exposure prevention is critical; treatment similar to adults but with careful monitoring 1.
Elderly: Consider comorbidities; management tailored to individual health status 1.
Comorbidities: Adjust treatment plans to accommodate coexisting respiratory or other conditions 1.Key Recommendations
Implement strict workplace exposure controls to minimize sensitizer exposure (Evidence: Expert opinion) 1.
Initiate inhaled corticosteroids as first-line pharmacological therapy for symptom control (Evidence: Moderate) 1.
Conduct environmental monitoring to confirm and assess exposure levels (Evidence: Moderate) 1.References
1 Grote AA, Kim WS, Kupel RE. Establishing a protocol from laboratory studies to be used in field sampling operations. American Industrial Hygiene Association journal 1978. link