Occupational asthma might be considered a silent disease: frequently seen but seldom considered. Although most adult patients seen by a clinician are employed, medical school curricula and residency training rarely cover occupational exposures and resultant diseases, even common ones that are encountered in a typical medical practice.

Occupational asthma has been estimated to constitute an average of 15% of adult asthma, and an even higher component of new-onset asthma in adults. This primer on occupational asthma is intended for the primary care clinician to provide the essential tools to diagnose and treat airways disease in the workplace.

Using a case vignette format, the basic approach to suspecting and establishing a diagnosis of occupational asthma is reviewed, and the thornier question of what to do about it is addressed. There are simple steps the clinician can take to establish the diagnosis, and occupational specialists are available to help along the way.

Treatment of occupational asthma follows the same guidelines as treatment of nonoccupational asthma. An added feature of the diagnosis involves identifying the inciting exposure in the workplace, however, and removing and restricting the patient from direct or indirect contact.

Further, the clinician must alert the designated occupational medicine specialist or health and safety officers that an occupational issue exists in the workplace and that other workers are at risk of similar disease. Although this may seem daunting, the primer provides a list of resources to contact for help.

Occupational asthma, similar to many other occupational diseases, can be a satisfying area of practice. Unlike other medical diagnoses, it provides a real opportunity for cure and prevention. This primer reviews the characteristics of primary, secondary, and tertiary prevention; efficient approaches; and who and where to turn for help.

It is hoped that after reviewing this primer, the reader will routinely include occupational asthma as part of his or her differential diagnosis in the adult patient with new or worsened asthma.