An approach to the diagnosis of occupational asthma

Assessing and treating work-related asthma

Work-related asthma is asthma that is caused or exacerbated by exposures at work. It is the most common form of occupational lung disease in developed countries. It has important impacts on the health and well-being of the affected individual, as well as consequences for society because of unemployment issues and workers' compensation claims. With ongoing exposure, occupational asthma can result in persistent airway hyperresponsiveness and, possibly, permanent disability for the individual. Thus, it is important for the clinician to be able to diagnose this disorder as quickly and accurately as possible. The evaluation of a patient with work-related asthma can be extensive. It includes obtaining a consistent history, identifying the cause in the workplace, and confirming the diagnosis with objective tests. After a diagnosis has been made, treatment must sometimes go beyond the medications used for nonoccupational asthma and include interventions to minimize or completely remove the individual from exposure to the causal agent if he or she has sensitizer-induced occupational asthma. In addition, once an individual has been identified with occupational asthma, steps should be taken to prevent the development of this disorder in other workers. The purpose of this article is to review the current literature and provide the clinician with a stepwise approach to the diagnosis and management of a patient with work-related asthma.

Pulmonary disease in rescue workers at the World Trade Center site

PURPOSE OF REVIEW

The catastrophic collapse of the World Trade Center (WTC) towers on September 11, 2001 created a large-scale disaster site in a densely populated urban environment. Over the ensuing months, tens of thousands of rescue, recovery and cleanup workers, volunteers, and residents of the adjacent community were exposed to a complex mixture of airborne pollutants. This review focuses on currently described respiratory syndromes, symptoms, and physiologic derangements in WTC rescue, recovery, and cleanup workers, discusses potential long-term effects on respiratory health, and draws parallels to community findings.

RECENT FINDINGS

Detailed qualitative and quantitative analyses of airborne pollutants with their changing composition during initial rescue/recovery and subsequent cleanup have been published. Major concerns include persistent aerodigestive tract inflammatory syndromes, such as reactive airways dysfunction syndrome (RADS), reactive upper airways dysfunction syndrome (RUDS), gastroesophageal reflux disease (GERD), and inflammatory pulmonary parenchymal syndromes, as well as respiratory tract and nonrespiratory malignancies. Aerodigestive tract inflammatory syndromes have now been documented in WTC exposed occupational groups, and syndrome incidence has been linked to WTC airborne pollutant exposure intensity. Community based investigations have yielded similar findings.

SUMMARY

While it is too early to ascertain long-term effects of WTC dust exposure, current studies already demonstrate a definite link between exposure to WTC-derived airborne pollutants and respiratory disease, both in the occupational and the community setting. A better understanding of causes and effects of this exposure will help in developing appropriate preventative tools for rescue workers in future disasters.

Epidemiology of occupational asthma

Information gathered through epidemiologic studies of occupational asthma is useful for the establishment of prevalence or incidence data for public health purposes, which can be used to determine which industry or workplace requires assistance from preventive services. These studies address etiologic questions regarding exposure and host risk factors. They can establish an exposure-response relationship that provides scientific basis for setting environmental control measures. They also examine the effectiveness of preventive 5 control measures. In the conduct of epidemiologic studies of occupational asthma, choosing the type of study to answer the study question is important. Observational studies have predominated in studies of occupational asthma. Although these types of studies have provided much useful data, they are associated with the problem of the healthy-worker effect. In the future, use of more robust epidemiologic study designs should foster a greater understanding of occupational asthma.