This Publication Is Searchable The Merck Manual of Diagnosis and Therapy Section 6. Pulmonary Disorders Chapter 75. Occupational asthma differs from bronchoconstriction in a person with idiopathic asthma who is exposed to an irritant. Many irritants encountered in the workplace may exacerbate idiopathic asthma, but such reactions do not constitute occupational asthma.
Occupational asthma affects only a minority of workers.
The list is continually growing. Responses can vary, and bronchospasm may occur soon after exposure or be delayed, eg, up to 24 h with nightly recurrences for a week or more without further exposure. Symptoms, Signs, and Diagnosis Patients generally complain of shortness of breath, chest tightness, wheezing, and cough, often with such upper respiratory symptoms as sneezing, rhinorrhea, and tearing. Symptoms may develop during work hours after specific dust or vapor exposure but are often not apparent until several hours after leaving work, which makes the association with occupational exposure less obvious. Nocturnal wheezing may be the only symptom.