Contribution of host factors and workplace exposure to the outcome of occupational asthma

The outcome of occupational asthma after diagnosis is often poor. The identification of factors associated with a worse outcome may help in the management of the disease, determining its prognosis and assessing the permanent impairment attributable to occupational exposure. The aim of this systematic review was to provide the available evidence from the medical literature to answer the question: "What is the contribution of host factors and workplace exposure to the risk of a bad outcome of occupational asthma?" A systematic literature search was conducted in March 2010. We retrieved 177 abstracts. Of these, 67 were assessed as potentially relevant. After full text evaluation, 35 articles that were actually relevant for the question were included in the analysis. The information obtained was sufficient to establish that older age, high-molecular-weight agents, impaired lung function and longer duration of exposure to the offending agent at the time of diagnosis had a negative role on the outcome of occupational asthma. Atopy and smoking at diagnosis did not seem to influence the outcome of occupational asthma. A limited number of studies considered sex and the pattern of asthmatic reaction on specific inhalation challenge and their findings were contradictory

Primary prevention: exposure reduction, skin exposure and respiratory protection.

Interventions for the primary prevention of occupational asthma have been reported in the medical literature, understanding the effectiveness of these efforts could help future interventions. The aim of our study was to evaluate the existing knowledge regarding the impact of controlling work exposure on the prevention of occupational asthma. We conducted systematic literature searches through April 2010 to examine if control of workplace exposures is effective for primary prevention of sensitisation and occupational asthma. The literature search for primary prevention of occupational asthma yielded 29 studies. Assessment of the available information led to the following conclusions and recommendations concerning primary prevention of occupational asthma. Exposure elimination is the strongest and preferred primary preventive approach to reduce the burden of occupational asthma. If elimination is not possible, exposure reduction is the second best option for primary prevention of occupational asthma. The evidence for the effectiveness of respirators in preventing occupational asthma is limited, and other options higher in the list of controls for occupational exposures, notably eliminating or minimising exposures at the source or in the environment, should be used preferentially. There is strong evidence to recommend not using powdered allergen-rich natural rubber latex gloves. There is weak evidence that suggests workers should minimise skin exposure to asthma-inducing agents

What are the benefits of medical screening and surveillance?

Pre-employment examination is considered to be an important practice and is commonly performed in several countries within the European Union. The benefits of medical surveillance programmes are not generally accepted and their structure is often inconsistent. The aim of this review was to evaluate, on the basis of the available literature, the usefulness of medical screening and surveillance. MEDLINE was searched from its inception up to March 2010. Retrieved literature was evaluated in a peer-review process and relevant data was collected following a systematic extraction schema. Pre-placement screening identifies subjects who are at an increased risk for developing work-related allergic disease, but pre-employment screening is too low to be used as exclusion criteria. Medical surveillance programmes can identify workers who have, or who are developing, work-related asthma. These programmes can also be used to avoid worsening of symptoms by implementing preventive measures. A combination of different tools within the surveillance programme, adjusted for the risk of the individual worker, improves the predictive value. Medical surveillance programmes provide medical as well as socioeconomic benefits. However, pre-employment screening cannot be used to exclude workers. They may act as a starting point for surveillance strategies. A stratified approach can increase the effectiveness and reduce the costs for such programmes