International Journal of Asthma, Allergy and Clinical Immunology Official Journal of the Spanish Society of Pediatric Allergy and Clinical Immunology

Migrat ion studies provide informat ion on the role of environmental factors on the development of atopy and respiratory disease. Internat ional studies provide st rong and obj ect ive evidence for an associat ion of atopic disease with westernisat ion.1 A metaanalysis has shown higher rates of asthma in immigrants. Immigrants moving to allergy prevalent count ries have general ly more al lergy and ast hma comparing both with nat ives, but also with respect to the prevalence in their count ries of origin.2 It has been postulated that parasite-burden in developing count ries is inversely associated with atopy and asthma. 3,4 Furthermore, cl imat ic condit ions for a high prevalence of geohelminths paral lel t hose for growth of dif ferent house dust mite (HDM) species. Up to now, most immigrant studies on an epidemiological background have addressed prevalence rates of asthma or allergy without taking into account the specifi c sensit isat ion to dif ferent aeroallergens. In our study region, HDM sensit isat ion is infrequent due to a predominant ly dry climate. Otherwise, many immigrants come from t ropical or subt ropical regions, where HDM are the predominant sensit ising allergens. We hypothesise that immigrants from these count ries, although developing allergic respiratory disease after migrat ing, could be sensit ised to dif ferent aeroallergens in comparison to nat ives. The aim of this study was therefore to compare the sensit isat ion profi le of allergic immigrants proceeding from helminth endemic developing count ries regions, with nat ive pat ients of our region, in which no signifi cant endemic helminth infect ion is known. In a mainly dry region (Madrid, Spain), we performed a cross-sect ional study of 49 consecut ive adult immigrant pat ients from South-America and the Philippines who at tended our Allergy Service for an allergological evaluat ion of rhinoconj unct ivit is or bronchial asthma (RCBA). Pat ients were included i f t hey had int erview based t ypical rhini t i s or rhinoconj unct ivit is symptoms and/ or bronchial asthma for at least one year. One hundred nat ive RCBA pat ients in the same age range of 23-63 years served as cont rol group. We asked for the age of migrat ion and onset of RCBA symptoms. Pat ients were assessed for seasonal and/ or perennial symptoms. They could be included in both groups, if seasonal exacerbat ion of perennial symptoms were present . Skin Prick Tests (SPT) were performed against house dust mites (HDM, Dermat ophagoides pt eronyssinus, D. f ar inae, Tyrophagus put rescent iae), animal dander (cat , dog), 5 pollen mixtures of grass, t ree and weed pollen and mould (Alt ernar ia al t ernat a, Cl adospor ium herbarum). SPT was performed in standard technique and was considered posit ive with a mean wheal diameter of ≥ 3 × 3 mm. Histamine at 1 % concent rat ion and sal ine solut ion 0,9 % (NaCl) were posit ive and negat ive cont rols. SPT data were analysed separately for HDM, pol len and PMD (group of non-HDM allergens: pollen, mould or dander). Stat ist ical analysis was performed using SPSS 15.0 for Windows Version (SPSS Inc.). ANOVA and Chi-Square-Test were used for evaluat ion of signifi cance of means and percentages, respect ively. Forty-four of 49 pat ients began to suffer RCBA after migrating t o our region wit h a mean lat ency of 3.8 ± 3.8 years (Fig. 1). Mean age of symptoms init iat ion was 36.3 ± 11.0 years and 30.6 ± 8.8 years in the cont rol group (p = 0.005). 75 % were female in immigrant pat ients and 68 % in nat ives (n.s.). Overall SPT react ivity was higher in immigrants than in nat ive