Mite allergen content in mattress dust of Dermatophagoides-allergic asthmatics/rhinitics and matched controls

It has been suggested that the mites Dermatophagoides pteronyssinus and D. farinae are important indoor environmental factors facilitating both the sensitization of atopic subjects and asthmatic attacks of house dust-sensitive patients. Contradictory results have been reported about the current exposure to mites or their allergens among patients and control groups of atopic or non-atopic subjects. In order to determine whether there is a difference in mite exposure levels between D. pteronyssinus-sensitized asthmatics and/or rhinitis and control subjects we considered a case-control study of 70 patients with asthma and/or rhinitis and positive skin test reactions to D. pteronyssinus and twice as many control subjects who were matched as to age and sex. The first control subject for each patient was an immediate neighbour of the patient and the second was patient arbitrarily chosen among hospitalized patients. Mite allergen exposure was measured in mattress dust collected under standardized conditions, by measuring Der p I+Der fI content and by performing a semiquantitative guanine determination (Acarex-test). The content of Der p I and Der fI was very high both in the homes of patients and those of healthy individuals: 69% of the total samples contained more than 10 micrograms Der pI+Der fI/g of dust. There was no significant difference between cases and controls with respect to Der p I, Der fI, Der p I+Der fI content and Acare class distributions. The calculated odds-ratios associated with the Acarex test and the mite allergens did not differ significantly from the level 1.0.(ABSTRACT TRUNCATED AT 250 WORDS)