Mite sensitivity and exposure in the city of Santa Fe, Argentina

Little information is available on mite allergen levels and rates of sensitization to domestic mites in South America. The purpose of this study was to establish the rate of sensitization to domestic mites in asthmatics and measure mite allergen levels in pillows and mattresses of mite allergic individuals in Santa Fe, Argentina. Dust samples were collected from the pillows and mattresses of 56 asthmatics (24 females and 32 males, mean age 17.6 +/- 11.5 years), who had been previously skin tested with standardized extracts of Dermatophagoides pteronyssinus, Dermatophagoides farinae and (1:50 w/v) extracts of Aleuroglyphus ovatus, Blomia tropicalis, Chortoglyphus arcuatus. A wheal > or = 3 mm was considered positive. Sensitization to Lepidoglyphus destructor and Euroglyphus maynei was determined by RAST and considered positive when a serum bound > or = 1% of the total counts added. Forty six individuals had a positive skin test to D. pteronyssinus, 43 to D. farinae, 27 to A. ovatus, 38 to B. tropicalis, 27 to C. arcuatus; 38 of 54 individuals had a positive RAST to E. maynei and 22 of 54 to L. destructor. The mean Group 1 (Der p 1 + Derf 1) level in pillows (n = 48) was 6.7 micrograms/g (1-55.4) and in mattresses (n = 52) 4.3 micrograms/g (1-38.8). There is a high degree of sensitization to domestic mites among asthmatics in Santa Fe. High mite allergen levels (> 2 micrograms/g) can be detected very often in pillows and mattresses.