Asthma, Occupational

KEY FEATURES

• Approximately 2–5% of all asthma cases are related to occupational factors

• May occur weeks to years after initial exposure and sensitization

CLINICAL FINDINGS

• Dyspnea, wheezing, cough, or a combination of all that correlate with exposure to the workplace

• Offending agents can be classified into low-molecular weight (eg, isocyanates, metals, wood dust, dyes and bleaches, resins and glues) and high-molecular weight (eg, animal proteins; flours; enzymes such as pancreatic extracts; plant-based proteins such as wheat, coffee beans, tobacco) chemicals

• Patients often report feeling better in the evenings or during weekends and vacations

DIAGNOSIS

• Requires a high index of suspicion and a careful history of workplace exposures

• Spirometry before and after exposure to the implicated substance

• Peak flow measurements at and outside of the workplace

• Bronchoprovocation testing is helpful in some cases

TREATMENT

• Bronchodilators

• Avoidance of further exposure to the offending agent