ALERGIJA NA PRŠICO IN ASTMA

Pri več kakor 85 % astmatičnih pacientih je prik test na pršico pozitiven, v primerjavi z 5 - 30 % celotne populacije.

Up to 85% of patients with asthma are skin prick sensitive to house-dust mites, as compared with only 5-30% of the general population. House-dust-mite sensitization is a dominant risk factor for asthma in the developed world in areas with high levels of mite allergens in homes. In addition, the importance of dust-mite sensitivity is being increasingly recognized in the developing countries.

Alergična senzibilnost na pršico predstavlja najbolj pomemben dejavnik pri razvoju astme.

On the east coast of the USA, sensitization to mite allergens is the single strongest risk factor for asthma among middle schoolchildren. Studies of 720 schoolchildren from Dunedin, New Zealand, found that positive skin prick tests to mite correlated with bronchial hyperreactivity. Wickman et al. reported that even in the areas with low mite-allergen exposure (Stockholm, Sweden) there was a close association between mite sensitization and asthma (odds ratio 4.9).

Pri otrocih senzibilnih na alergen pršice se verjetnost razvoja astme podvoji z podvojitvijo izpostavljenosti na alergene pršice.

The results of recent studies from Australia provide remarkable evidence of the role of exposure to mite allergens in childhood asthma. Several large random samples of children were studied in six regions of New South Wales with a range of levels of house-dust-mite allergens. The proportion of children, sensitized to dust mites was higher in areas with higher allergen levels. Furthermore, children skin prick test positive to mites in each of the areas were at significant risk of having asthma, and the magnitude of risk increased with the increasing exposure to mite allergens. After adjusting for sensitization to other allergens, the risk of house-dust-mite-sensitized children having asthma approximately doubled for every doubling of the level of exposure to mite allergens.

Sporik et al. reported that in Poole, UK, exposure to Group 1 house-dust-mite allergen greater than 10 mg/g of household dust measured in infancy was associated with a 4.8-fold relative risk of developing atopic asthma by the age of 10 years. Furthermore, IgE-mediated sensitization to dust mites at age 10 years was associated with a 19.7 odds ratio of having asthma.

Izvleček iz: Custovic A, Simpson A, Woodcock A. Importance of indoor allergens in the induction of allergy and elicitation of allergic disease. Allergy 1998; 53 (suppl 48):115-120.

Izpostavljenost alergenom pršice ima pomembno vlogo pri razvoju astme. Izogibanje, oziroma preprečitev stika z alergeni v otroštvu ima pomembno vlogo pri primarni preventivi .

Exposure to HDM allergen plays a key role in the causation and persistence of asthma. Avoidance of exposure, particularly in early life, may have a role in the primary prevention of asthma.

Evidentno je da učinkovita preventivna strategija pri zatiranju pršice izboljšuje stanje astmatičnih pacientov.

Where HDM-avoidance interventions have been successful in producing a measurable, sustained reduction in HDM levels, particularly in the bed, this has been associated with evidence of clinical benefit. This has usually involved mattress encasement or similar intensive efforts directed at the bed. Where no sustained reduction in exposure was achieved, no clinical benefit was observed. There is substantial evidence that effective HDM-avoidance strategies which focus on the bed will produce improvements in outcomes for adults and children with asthma.

Izvleček iz : Marks GB. House dust mite exposure as a risk factor for asthma: benefits of avoidance: Allergy 1998; 53 (Suppl 48): 108-114.