Occupational Allergies

Occupational immune diseases are new emerging illnesses that affect workers in industrialized societies. Occupational exposures to substances in the workplace environment can cause inflammation, allergy, or other potentially detrimental immune responses. Personal exposure to a variety of chemicals can exacerbate immune diseases such as contact dermatitis as well as respiratory diseases including rhinitis, asthma, and hypersensitivity pneumonitis. Next to illnesses due to repeated traumatic injury, contact dermatitis is the second most commonly reported occupational illness. It can prevent individuals from performing job-related tasks or preclude working altogether. Occupationally related contact dermatitis is a significant public health burden with combined direct annual cost estimates of up to $1 billion in the USA for medical costs, workers compensation, and lost time from work. Respiratory morbidity is also a significant burden to public health leading to lost productivity. Prevalence rates for occupational rhinitis are significant, varying by occupation between 5% and 65% and costing an estimated $593/year/employee due to productivity losses. Conservative estimates made by the American Thoracic Society in 2003 estimate that 15% of chronic obstructive pulmonary disease and asthma cases were work related and cost approximately $7 billion in lost productivity in the USA With the changing work environment, new occupational hazards continue to emerge which require immunologic characterization. In order to reduce the morbidity and mortality associated with these illnesses, it is critical that we identify the allergens and understand the immunological mechanism by which they exacerbate immune-mediated respiratory and dermal diseases. Specific understanding of mechanism has direct implications in developing appropriate intervention and prevention strategies. Occupational allergy can be stratified into high-molecular weight -allergen and low-molecular-weight-allergen mediated responses. Different immunologic mechanisms mediate allergic reactivity to these occupational allergens as highlighted in this issue by Talini et al. High-molecular-weight (HMW) allergens (typically proteins) induce type I hyper-sensitivity responses or typical allergies by inducing IgE anti-bodies which lead to a continuum of symptoms including rhinitis (rhinosinusitis, conjunctivitis), hives, asthma, and life-threatening anaphylaxis. Patients with HMW-allergen-induced asthma show a greater frequency and severity of the early-phase response but are less likely to demonstrate a late-phase response. Occupational outbreaks of reactions to HMW allergens can occur episodically and can be severe and life altering for those affected. These allergies can affect large numbers of easily identified workers in specific industries which can reach epidemic proportions such as latex allergy and Baker's asthma. It can present in a less-well-defined population or as local occurrences …