Asthma in the Workplace PDF

Preface

Although occupational asthma was recognized as early as the 18th century by Ramazzini, its importance as a significant hazard in the workplace was not widely appreciated until the spurt in industrial technology after World War II. The literature concerning workplace asthma has steadily increased since the great impetus given by Professor Jack Pepys, who can be considered the father of occupational asthma and to whom the first three editions of this book were dedicated. The frequency of asthma in the workplace and occupational asthma has increased with a recent plateau and is now one of the most prevalent occupational lung diseases (chap. 3). In some industrialized countries, occupational asthma has even replaced pneumoconiosis as the most common work-related respiratory diseases.

Asthma in the workplace is a complex entity that is not equivalent to new-onset occupational asthma as defined in the first chapter of the first two editions of the book but has been revised in the third edition to account for the fact that approximately 10% of asthmatic subjects have preexisting or concomitant nonoccupational asthma and to note that conditions at work worsen their symptoms (i.e., work-exacerbated asthma).

Occupational asthma is a condition that has attracted the interests of a wide variety of disciplines: allergists, immunologists, pulmonologists, immunotoxicologists, occupational health specialists, aerosol scientists, hygienists, and epidemiologists. Outbreaks of occupational asthma in specific work settings are ideal, mini-epidemiological paradigms of nonoccupational asthma and provide excellent opportunities for investigating the source, the characteristics of the emission–dispersion cycles, and the health impact of inciting agents. The ready access to such integrated data in a defined setting provides an ideal milieu and investigational model for further advancement of knowledge about the pathophysiological pathways and natural history of asthma by specialists from various disciplines. In addition, the economic and social hardships imposed on a worker with refractory symptoms associated with occupational asthma may require consultation with a psychologist and a legal counsel. These interactions have clearly established that the features of occupational asthma are unique and often at odds with medical dogma derived from the surveillance, diagnosis, and prevention of mineral dust–induced lung disorders.

The enthusiastic response to publication of the first, second, and third editions of this book and the number of literature citations attributed to it have more than justified preparation of a fourth edition.

Discovery and research in workplace-related asthma have continued at a rapid pace and have served as the impetus for this updated and revised edition. In addition, coverage of several specific areas of interest that had not yet clearly evolved prior to publication of the first three editions has been either added or expanded.

The fourth edition retains the international nature in the coalition of editors and individual contributors. The common goal of this cooperative effort was to prepare an authoritative, educational resource for primary care physicians, occupational health specialists, allergists, and pulmonologists.

To make this reference book particularly germane for primary care providers to develop skills in the early recognition of the disease, this edition has a new feature at the beginning of relevant chapters: a clinical history or a workplace scenario with referrals in the main part of the chapter. As the diagnosis of occupational asthma is often difficult because of multiple causalities in many occupational environments, the variability of symptoms and patterns of late-phase asthmatic reactions, the requirements for special diagnostic procedures, and the unpredictability of onset and persistence of symptoms, special emphasis has been given to an algorithm of clinical diagnosis, immunological evaluation, and physiological methods of evaluation (chaps. 6–9) as a practical guide for primary care physicians.

New chapters on assessment and management of the workplace have been added for industrial hygienists. Expanded chapters on medicolegal aspects, prevention, and surveillance (chaps. 11–13) address the social outcomes of workers disabled by asthma and should serve as useful reference sources for occupational health physicians, workers' compensation administrators, private insurers, attorneys, adjudicators, and legislators.

The chapters concerning epidemiology and disease entities have been prepared to provide sufficient in-depth information for occupational health and other medical subspecialists primarily concerned with asthma in the workplace. Although occupational asthma represents the core of this book, this edition includes chapters on irritant-induced asthma and reactive airways syndrome and asthma exacerbated at work, with all conditions being grouped under the general theme of "asthma in the workplace." Conditions that share clinical, functional, or immunological features to workplace asthma (eosinophilic bronchitis, airway diseases due to organic dust exposure, chronic obstructive pulmonary disease due to occupational exposure, hypersensitivity pneumonitis, building-related illnesses) are covered in specific chapters 23 and 25 to 28. The relationship of conditions frequently associated with workplace asthma is reviewed in chapters 24 (occupational rhinitis) and 29 (occupational urticaria and contact dermatitis).

The book is organized into five main parts:

Part I, "General Considerations," contains chapters on definitions, historical background, epidemiology, genetics, pathophysiology, and animal models.

Part II, "Assessment" includes chapters that delineate guidelines for assessing the worker and the workplace.

Part III, "Management" includes chapters that propose guidelines for the management of worker and the workplace, including compensation aspects.

Part IV, "Specific Agents Causing Immunological Occupational Asthma" provides detailed information about specific agents (including a variety of high- and low-molecular weight agents).

Part V, "Specific Disease Entities and Variants," covers other types of work-related asthma conditions, for example, irritantinduced asthma, asthma exacerbated at work, eosinophilic bronchitis as well as acute and chronic asthma-like syndromes. Occupational rhinitis, urticaria and allergic contact dermatitis are also covered in this section.

Most of the chapters have been revised and new chapters have been introduced without adding to the overall length of the book. Some of the chapters have new or additional contributors. The preparation of individual chapters by multiple authors and the endeavor that the authors have put forth in this edition are similar to meta-analyses that compare different published health-related data pertaining to a given research question. As often occurs with meta-analyses, agreement at times is incomplete. Above all, the authors and editors have attempted to balance opposing views as objectively as possible. In most cases, this balancing process was successful in arriving at editorial consensus. Where this was not possible, the data appear with the caveat that a controversy exists and resolution is not possible, because definitive data are either not yet available or under investigation. These critical assessments have been rewarding educational experiences for the editors and authors. We hope that this joint effort will not only provide pragmatic information for current clinical applications but also serve as a foundation for significant new research information that will most assuredly advance the discipline during this new millennium.

The preparation of this fourth edition was sadly marked by the recent loss of one of our editors, Dr. I. Leonard Bernstein, a most renowned thought leader and authority in allergy and immunology and an attentive, stimulating, and cheerful colleague. He had played a leading role in initiating, writing, and editing the first three editions of this textbook and had dedicated enormous energy and effort toward its success. The editors wish to dedicate this fourth edition to the beloved memory of Leonard, our dear friend and colleague.