THE IMPORTANCE OF STORAGE MITE ALLERGENS IN OCCUPATIONAL AND DOMESTIC ENVIRONMENTS

Abstract:
The prevalence and severity of allergic diseases such as asthma, rhinitis and eczema in the developed world are increasing, resulting in greater focus on the causative agents. The majority of cases involve sensitivity to allergens from arthropods. Storage mites are recognised as a source of allergens by inhalation in certain occupational environments and in the domestic environment. To minimise the initial sensitisation and subsequent development of these diseases, it is essential to reduce chronic exposure to these allergens. Recent research in the United Kingdom suggests that this may be increasingly difficult. In a study of grain stores it was found that two of the common storage mite species were unlikely to be controlled by the most frequently used grain protectant. Other work has shown for the first time that storage mites are regularly found on sheep and dairy cattle farms, suggesting an additional circumstance for occupational exposure. A study of cereal-based foodstuffs has found that over a third of samples contained storage mites. Ingestion represents another route contributing to the overall allergen load. The numbers of mites found were low but some were probably alive immediately before analysis and one of the most infested samples was an item of baby food. Since the risk of sensitisation is greater early in life, work is urgently needed to quantify the threat to health. This depends upon establishing not the number of storage mites but the amounts of their allergens. This in turn requires identification of which allergens poses the greatest health threat and the development of methods to quantify their presence. Thresholds of exposure to these allergens for clinical effects must be properly established and comparison of exposure levels in both domestic and occupational environments must be made.