Allergen Avoidance and Allergy Relief

TITLE: Methods and effectiveness of environmental control. AUTHORS: Tovey E; Marks G AUTHOR AFFILIATION: Institute of Respiratory Medicine, Department of Medicine, University of Sydney, NSW, Australia. SOURCE: J Allergy Clin Immunol 1999 Feb;103(2 Pt 1):179-91 CITATION IDS: PMID: 9949306 UI: 99135982 ABSTRACT: In recent years the role of allergen exposure and atopy, and the interaction between them in the clinical expression of allergic disease, has been examined in a quantitative manner in epidemiologic studies. Such analyses suggest that avoidance of exposure to domestic allergens is a critical element in integrated strategies for both the prevention and the management of asthma. The promise of primary intervention in high-risk infants, as shown in the Isle of White study, has been confirmed in a recent study in Japan, and at least 4 similar trials are in progress. Applying these principles to the management of symptoms in patients with chronic asthma has proved more difficult, and it is likely that many earlier studies were poorly designed to test the hypothesis that allergen avoidance was clinically useful. Recent studies with patients moved to high altitudes during seasonal reductions in mite exposure and randomized controlled interventions in houses have all shown improvements in clinical manifestations of asthma. These recent trials have also demonstrated something that was less certain–that massive reductions in domestic allergen exposure can be achieved and that people will adopt the significant changes to their domestic environment and lifestyles if the risks and benefits are known. In the future, it seems likely that better study designs, as well as improvements in methods to monitor exposure and clinical outcomes, will provide further support for the role of allergen avoidance in the prevention and management of asthma.

TITLE: Reduction of bronchial hyperreactivity during prolonged allergen avoidance. AUTHORS: Platts-Mills TA; Tovey ER; Mitchell EB; Moszoro H; Nock P; Wilkins SR AUTHOR AFFILIATION: Institute of Respiratory Medicine, Department of Medicine, University of Sydney, NSW, Australia. SOURCE: Lancet 1982 Sep 25; 2(8300): 675-8 CITATION IDS: PMID: 6126624 UI: 83011723 ABSTRACT: To study the long-term effects of avoiding domestic allergens, nine asthmatic patients who were allergic to dust mites lived in hospital rooms for two months or more. In all patients symptoms and early morning peak flows improved. In seven patients anti-asthma treatment could be reduced and it was possible to carry out repeated bronchial provocation with histamine. Five of these patients showed a progressive eightfold or greater increase in the concentration of histamine necessary to provoke a 30% fall in forced expiratory volume in one second (PD30). The increase in PD30 in the seven patients during their period of living in hospital was highly significant. Avoidance of important allergens seems not only to result in clinical remissions but in many cases also reduce bronchial hyperreactivity.

TITLE: House dust mite avoidance measures improve peak flow and symptoms in patients with allergy but without asthma: a possible delay in the manifestation of clinical asthma? AUTHORS: Cloosterman SG; Hofland ID; Lukassen HG; Wieringa MH; Folgering HTh; van der Heide S; Brunekreef B; van Schayck CP AUTHOR AFFILIATION: Department of General Practice and Social Medicine, Medical Centre Dekkerswald, University of Nijmegen, The Netherlands. SOURCE: J Allergy Clin Immunol 1997 Sep; 100(3): 313-9 CITATION IDS: PMID: 9314342 UI: 97457998 BACKGROUND: Asthma caused by allergy to house dust mite is a growing problem. Patients with allergy who do not have asthma (yet) might develop asthma depending on exposure to precipitating factors. OBJECTIVE: We sought to determine whether house dust mite avoidance measures have an effect on the development of asthma. METHODS: Patients with allergy (n = 29) who had no diagnosis of asthma (FEV1 of 99.1% +/- 10.6% of predicted, peak flow variability of 5.21% +/- 3.41%, reversibility of FEV1 after 400 microg salbutamol of 3.92% +/- 3.75% according to the reference values) were randomly allocated (subjects blinded) to a treatment (n = 16) and a placebo group (n = 13). House dust mite avoidance treatment consisted of applying Acarosan (Allergopharma, J. Ganzer KG, Hamburg, Germany) (the placebo group used water) to the floors (living room, bedroom), and the use of covers for mattresses and bedding that were impermeable to house dust mite (the placebo group used cotton covers for mattresses only). We tested whether the intervention had an effect on peak flow parameters and asthma symptom scores during 6 weeks of treatment. RESULTS: Significant improvements were seen in the treatment group in symptom scores (Borg score) for disturbed sleep, breathlessness, wheeze, and overall symptom score. Slight but statistically significant improvements in peak flow (morning, evening, and variability) were seen in the treatment group also. No significant changes were seen in the placebo group. CONCLUSIONS: Although this study is not long enough to study the development of asthma, the results indicates that house dust mite avoidance measures had an effect on peak flow parameters and asthma symptoms in patients with allergy but without asthma. These findings might implicate that a shift in developing clinically manifest asthma could be achieved with house dust mite avoidance measures. To give a better answer to whether preventing the development of asthma is possible, larger studies with a longer follow-up period are necessary.

TITLE: Reducing domestic exposure to dust mite allergen reduces bronchial hyperreactivity in sensitive children with asthma. AUTHORS: Ehnert B; Lau-Schadendorf S; Weber A; Buettner P; Schou C; Wahn U AUTHOR AFFILIATION: University Children’s Hospital, Berlin, Germany. SOURCE: J Allergy Clin Immunol 1992 Jul;90(1):135-8 CITATION IDS: PMID: 1629503 UI: 92332907 ABSTRACT: (not available)

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