Allergen avoidance in the treatment of asthma and atopic disorders

Abstract

The majority of asthmatic patients are atopic humidity is too low to support mite popu--that is, they have IgE mediated sensitivity lations. Mite sensitive asthmatic children had to common inhalant allergens. Exposure and a progressive reduction in non-specific BHR sensitisation to allergens from the house dust when taken from their homes in Holland mite is established as an important risk factor to the mite-free environment of Davos, for asthma in most parts of the world. In Switzerland. 38 39 Similarly, a progressive readdition, several recent studies have provided duction in asthma symptoms occurred in chilevidence of the importance of exposure to other dren admitted to the residential home at indoor allergens, particularly those from Misurina (altitude 1756 m). 40 Further studies cats, dogs, and cockroaches. [25][26][27][28][29] The rate of from Misurina reported a significant decrease sensitisation to mites is directly related to expo-in mite allergen-induced basophil histamine sure, 30 whilst conversion from sensitisation to release, mite-specific serum IgE level, and non-sensitisation may occur in indoor en-methacholine BHR with reversal of this trend vironments with low allergen levels. 31 after 15 days of allergen re-exposure at sea The severity of asthma is also related to level. 41 Peroni et al found a significant reduction allergen exposure. [32][33][34][35] Objective indices of in total and mite-specific serum IgE and allerasthma severity such as bronchial hyper-gen-induced BHR after three and nine months reactivity (BHR), forced expiratory volume in at Misurina. 42 These results suggest that avoidone second (FEV 1 ), and variability in peak ance of mite allergen leads to a decrease in expiratory flow rate (PEFR) in patients sens-airway inflammation with consequent imitised to dust mites correlate with the level of provement in non-specific BHR and sympmite allergens in their beds. 32 Peat et al found toms, and that re-exposure results in a rapid a similar prevalence of sensitivity to mites in relapse. The high altitude studies were not children living in areas with two different levels controlled and there is a possibility that avoidof exposure to mites but BHR was more severe ance of other domestic factors such as exposure in sensitised children living in the area with the to pets or environmental tobacco smoke conhighest mite levels.

Effects of physical interventions on house dust mite allergen levels in carpet, bed, and upholstery dust in low-income, urban homes.

“…Several environmental factors have been shown to be associated with concentrations of HDM allergens, including indoor temperature and humidity (15,33,34). We found no statistically significant differences in these variables between homes assigned to the different interventions for each of the three sites.…”

Effectiveness of education for control of house dust mites and cockroaches in Seoul, Korea

“…Asthma is unequivocally associated with cockroach infestation and attempts to reduce cockroach allergen exposure rely heavily on improving patient education (Custovic et al, 1998). Moreover, it was described that reduction in number of cockroaches and in total allergen in bedding dust could be achieved by educational intervention by peer educators (McConnell et al, 2005).…”

The role of allergy in childhood asthma

“…As reviewed by Tovey & Marks (63) and Custovic et al (64), several controlled, randomized studies have demonstrated that some avoidance measures, especially those for allergens of house-dust mite, have proven to be effective in reducing the level of allergens and improving disease control. For elimination of allergens of housedust mite, encasing of mattresses has been shown to be effective, signi®cantly reducing allergen level, BHR, in¯ammation markers, and symptoms (65±72).…”

“…There is no generally accepted criterion for threshold levels of allergens inducing sensitization or allergic symptoms, although there seems to be a correlation between exposure levels and sensitization, as well as a correlation between exposure levels and severity of asthma (for review, see ref. 45). Other studies have con®rmed a correlation with skin prick reactivity to indoor allergens as a marker of asthma severity (10, 46±51).…”