Environmental and Social Influences on Skin Test Results in Children

Skin tests with 13 inhalant allergens were performed in 788 children with respiratory allergy. Positive reactions were common to animal danders (65%), to grass pollens (55%) and to tree pollens (44%) but rare to moulds (13%) and to house dust mite (12%). Children exposed to cows, dogs or horses at home more often had skin test reactions to these allergens than the children not exposed, but reactions to cat dander occurred as frequently in children exposed to cats at home as to those not exposed. Reactions to three pollens occurred most often in children from upper social classes and from urban areas and reactions to house dust mite occurred most often in children from lower social classes and from rural areas. Children with positive reactions to house dust mite came from larger families than children with negative test results.     

Sensitization to house dust mites in Reykjavik, Iceland, in the absence of domestic exposure to mites

BACKGROUND: House dust mites are common sources of indoor allergens. In Reykjavik, Iceland, 9% of the young adult population had serum-specific IgE to Dermatophagoides pteronyssinus. Sensitization to mites is usually assumed to be due to exposure to house dust mites in the indoor environment. This investigation was carried out to measure the concentrations of house dust mite allergens and to investigate which species of mites were present in beds in Iceland. METHODS: A total of 197 randomly selected adults were visited at home using the European Community Respiratory Health Survey (ECRHS) II Indoor protocol. Dust samples were collected from mattresses for measurement of house dust mite allergen concentrations and to estimate the number and type of house dust mites. Additional samples from mattresses and floors were collected from the homes of 10 patients with positive skin prick tests (SPT) to D. pteronyssinus. House dust mite allergen concentrations were measured using ELISA and examination of mite species was carried out using microscopy. Climatic parameters were assessed using psychrometer readings in the bedrooms and outdoors. RESULTS: We found two single mite specimens, both D. pteronyssinus, in two dust samples. Mite allergen analyses indicated that two other dust samples had Der f 1 results close to the cut-off of 0.1 microg/g of dust. No samples were positive for Der p 1. In an additional collection of dust from the homes of 10 SPT-positive patients no Dermatophagoides spp. were found. CONCLUSIONS: Reykjavik citizens are exposed to extremely low amounts of house dust mite allergens in their homes. Possible alternative sources for sensitization are discussed, such as bird nests, exposure from travelling abroad, or other mites or invertebrates that cross-react with house dust mite allergens. Our findings suggest that exposures other than to house dust mites indoors are possible sources of mite allergen exposure.     

A clinical and environmental study of the aeroallergens of the islands of Bermuda

The major allergen responsible for allergic respiratory disease in the islands of Bermuda has been shown to be derived from Dermetophagoides pteronyssinus. 73% of the atopic group included in the survey gave weal and erythema reactions to extracts of this mite, whereas only 30% reacted to mixed pollen extracts and 10% to mould extracts. D. pteronyssinus was isolated from all house dust samples and it represented 63% of the total mite population. Allergic disease was predominantly of a perennial nature, with only a modest seasonal influence, and pollen counts were low throughout the year.     

Relationship of Allergen-Specific IgE Antibodies, Skin Prick Tests and Allergic Disorders in Unselected Adolescents

The relationship between serum levels of allergen-specific IgE (RAST) and skin prick test reactivity and allergic disorders was evaluated in 137 subjects randomly selected from an adolescent population. All subjects were prick tested with six common allergens, interviewed and physically examined. In addition, serum was collected for RAST analysis with three to six allergens. At least one positive RAST result (score 1-4) was observed in 40% and at least two positive RASTs in 22% of the subjects. Boys experienced more RAST reactions and generally with higher scores than girls. For instance, 26% of boys but only 11% of girls were RAST positive to timothy grass pollen. The correlation between prick test and RAST results was better with pollens than with house dust and animal epithelia. When the test results were discordant, the skin test was usually positive and RAST negative. Many of the small skin reaction (weal diameter 3-4 mm) were accompanied by a negative RAST. Respiratory allergy was closely connected with both positive skin test and RAST reactivity, while atopic dermatitis was less related. In 17% of the adolescents positive skin tests and in 14% positive RASTs occurred in the absence of any allergic symptoms. We conclude that a positive RAST score 3-4 to inhaled allergens is a strong indicator of clinical allergy but low scores 1-2 are frequently found in healthy young people.     

过敏性鼻炎患儿过敏原特异性IgE检测与临床意义

目的 了解过敏性鼻炎儿童主要过敏原分布情况及特点,以指导临床防治.方法 采用免疫印迹法体外定量检测患儿血清中特异性IgE抗体及20种常见过敏原.结果 938例过敏性鼻炎患儿中,100%至少对一种以上的过敏原呈阳性反应,其中487例患儿总IgE〉400IU/Ml,230例患儿总IgE在200IU/ml~400IU/ml之间.在检测20种过敏原中以户尘螨和屋尘的阳性率最高（90.0%,80.8%）.结论 过敏性鼻炎患儿至少有一种特异性IgE抗体显著增加,户尘螨、屋尘、动物皮屑、羊肉和牛奶是引起儿童过敏性鼻炎的主要过敏原.儿童在春秋温暖季节易发过敏性鼻炎.     

House dust mite and cockroach exposure are strong risk factors for positive allergy skin test responses in the Childhood Asthma Management Program

BACKGROUND: Children with asthma have a high prevalence of environmental allergies, especially to indoor allergens. The relationships of exposure to indoor allergens (dust mites, cat, dog, cockroach, and molds) and other host factors to allergy sensitization have not been evaluated simultaneously in a large cohort. OBJECTIVES: We studied 1041 children aged 5 to 12 years with mild-to-moderate asthma to determine risk factors associated with having positive allergy skin test responses to indoor allergens. Also, we described, compared, and contrasted 6 allergens in the home environments of these children from 8 North American cities. METHODS: Data were used from baseline visits of the Childhood Asthma Management Program. Patients' sensitivities to house dust mites (Dermatophagoides farinae and Dermatophagoides pteronyssinus), cats, dogs, cockroaches, and molds were examined for relationships to demographic variables, home dust allergen exposures, number of other positive allergy skin test responses, total serum IgE levels, and smoking in the home. RESULTS: San Diego (78.5%) and Toronto (59.3%) had the topmost percentages of homes with moderate-to-high house dust mite levels. Boston (21.5%), St Louis (16.3%), and Baltimore (13.4%) had the highest percentages of homes with detectable levels of cockroach allergen. For house dust mites, the higher the level of allergen exposure, the more likely patients were to have positive allergy skin test responses, with relative odds of 9.0 (95% confidence interval, 5.4-15.1) for those exposed to high mite levels (>10.0 microg/g dust) relative to those unexposed. Even exposure to low levels of mite allergen (0.020-2.0 microg/g) was found to be a significant risk factor for sensitization. For cockroach allergen, those with detectable home exposure were more likely to have positive skin test responses (relative odds, 2.2; 95% confidence interval, 1.3-3.8) than those with undetectable exposure. In contrast, levels of exposure to cat, dog, and mold allergens were not related to sensitization rates. For cat allergen, this may reflect lower rates of cat ownership among highly sensitized subjects. Furthermore, the number of allergy skin test responses that were positive, excluding the test for the outcome of interest for each model, and total serum IgE levels were strong independent predictors of sensitization. CONCLUSIONS: Levels of exposure determined by house dust analysis are important determinants of sensitization for dust mite and cockroach allergen. This relationship was not demonstrable for cat, dog, or mold allergens, possibly because of confounding factors. For all allergens studied, the degree of atopy, determined by the total number of positive skin test responses or by total serum IgE levels, is an important contributing risk factor for sensitization.     

Sensitivity to common allergens: relation to respiratory symptoms and bronchial hyper-responsiveness in children from three different climatic areas of Australia

In order to examine further the relation between atopy, as defined by skin-prick tests, and respiratory illness, we studied three populations of schoolchildren aged 8-11 years and living in different climatic areas of New South Wales, Australia. Skin-prick tests were performed using 13 commercial allergen extracts. Respiratory and allergic symptoms were assessed using a self-administered questionnaire to parents and bronchial hyper-responsiveness (BHR) was measured by histamine inhalation test. We defined current asthma as BHR together with symptoms of wheeze in the 12 months prior to study. Children with one or more positive skin weals of greater than or equal to 3 mm had significantly more recent wheeze, hayfever, eczema and BHR than children with smaller weals (P less than 0.001). In each area, 95-97% of all atopic children were sensitized to one of the following seven allergens: house dust, Dermatophagoides farinae, D. pteronyssinus, cat dander, plantain, rye grass, and Alternaria tenuis. Thus, these seven selected allergen extracts and a skin weal of 3 mm could be used to detect clinically relevant atopy in these populations of children. Sensitivity to house dust mite had the strongest independent association with current asthma in all three areas. The associations of other allergen sensitivities with BHR or current asthma were area dependent, indicating the influence of local allergen levels on respiratory illness in children. The potency of house dust mite sensitivity in increasing the risk of children having BHR and current asthma is confirmed.     

Association between mite allergen (Der p 1, Der f 1, Blo t 5) levels and microscopic identification of mites or skin prick test results in asthmatic subjects

BACKGROUND: Mite allergens have been involved in airway sensitization and allergic diseases. Immunoassays for the identification and quantifiction of house dust mite (HDM) allergens are useful to improve the knowledge of regional mite fauna and the remediation of mite allergens in allergic diseases. The present study analyzed the association between levels of HDM allergen and results of mite identification or skin prick test (SPT) in two different areas of Bahia, Brazil. METHODS: Forty-two asthmatic subjects from a rural area (group I; n = 21) and a slum (group II; n = 21) were evaluated through SPT with HDM allergens and had dust samples collected at their homes for mite identification and allergen measurements. RESULTS: Positive SPT to Dermatophagoides pteronyssinus, Dermatophagoides farinae and Blomia tropicalis allergens were observed in 42.9, 38.0 and 42.9% subjects from group I and in 47.6, 19.0 and 33.3% subjects from group II, respectively. D. pteronyssinus and B. tropicalis were identified in approximately 76 and 50% of samples from both groups, respectively. D. farinae was identified in 38.0 and 9.5% of samples from groups I and II, respectively (p < 0.005). Der p 1, Der f 1 and Blo t 5 detection were associated with mite identification (p < 0.05). Association between HDM allergen levels over 2 microg/g of dust and positive SPT occurred only with D. pteronyssinus (p < 0.0001). CONCLUSIONS: D. pteronyssinus was the most prevalent mite species in this study followed by B. tropicalis and D. farinae. Immunoassays done to measure mite allergens were associated with mite-species identification. We conclude that these three mite species must be included on panels for the diagnosis of allergic airway diseases in subjects living in such regions.     

Predominance of mite allergy over allergy to pollens and animal danders in a farming population

The prevalence of IgE-mediated hypersensitivity to respiratory allergens, including Lepidoglyphus destructor (a storage mite) and Dermatophagoides pteronyssinus , was studied in a rural population of Gotland, a Swedish island in the Baltic Sea. A sample of 440 farmers underwent examination, comprising skin-prick tests (animal danders, pollens, moulds, house dust mite and wheat) and blood sampling for radio-allergosorbent tests (RAST) (birch, Timothy grass, dog, D. pteronyssinus, Cladosporium and L. destructor ). The highest prevalence of positive skin-prick tests was noted for D. pteronyssinus (6.0%). Low prevalences of positive skin-prick tests, 0.7-2.7%, were found for pollens, animal danders and moulds. Among the tested allergens, D. pteronyssinus and L. destructor yielded the highest prevalences of positive RAST results, namely 5.2 and 6.8%, respectively. Most farmers with allergy to pollens and animal danders had symptoms both from the upper and lower airways and from the eyes. Among farmers with both asthma and rhinoconjunctivitis, the prevalence of positive RAST results for L. destructor and D. pteronyssinus were similar. The present study clearly demonstrates that mites are by far the most important allergens in the farming population on Gotland, whereas otherwise common allergens such as pollen and animal danders are clearly less significant.     

Relationship between aeroallergen and food allergen sensitization in childhood

BACKGROUND: Previous studies measuring the prevalence of allergen sensitization have been relatively small and used small numbers of allergens. To effectively evaluate children with atopic disease, we need an accurate knowledge of which allergens are important. OBJECTIVE: To measure the prevalence of sensitization within a large unselected birth cohort, to examine the associations between sensitization to different allergens and determine whether atopy can be defined by a small panel of allergens. METHODS: The Avon Longitudinal Study of Parents and Children is a population-based birth cohort of 13,638 singletons surviving to 4 weeks of age. The cohort was skin tested at 7 years of age to house dust mite (Dermatophagoides pteronyssinus), grass pollens, cat, peanuts, mixed tree nuts and egg and one of three other panels: animal danders, foods or aeroallergens. Sensitization was defined as a weal diameter of > or =3 mm. The strength of associations between sensitization to different allergens was tested by calculating the odds ratio adjusted for sensitization to D. pteronyssinus and grass pollen and gender. RESULTS: Valid data were obtained from 6412 singletons. Sensitization was most common to aeroallergens: grass pollens (8.5%), D. pteronyssinus (7.8%), cat (4.9%), D. farinae (3.6%), dog (2.7%), horse (1.4%), rabbit (1.4%). Of the foods tested, the most common sensitization was to peanut (1.4%) and mixed tree nuts (1.0%). More than 95% of subjects with sensitization to any of the 29 allergens tested were sensitized to one of grass, D. pteronyssinus or cat allergen. There were strong associations of multiple sensitizations both within and between different allergen classes (pollens, animals, foods, peanut and tree nuts). CONCLUSIONS: Seven-year-old children in the UK are primarily sensitized to aeroallergens, but also to peanuts and tree nuts. There are strong associations between sensitization within allergen groups as well as between allergen groups. Further studies are required to observe whether similar associations are seen with clinical allergy to these allergens.     

Eliminating Dermatophagoides farinae spp. (Acari: Pyroglyphidae) and their allergens through high temperature treatment of textiles

House dust mite allergens cause allergy and asthma in sensitized individuals. The allergens they produce are known to resist decay under natural household conditions and are thought to accumulate until removed. We sought to evaluate the effects of high temperature (96 degrees C) generated by a hard surface cleaner on live mite populations of American house dust mites, Dermatophagoides farinae Hughes and their allergens in carpet and mattresses. Statistically significant (P < 0.05) mite mortality (100%) was observed in response to treatment in both textile surfaces. Similar effects were observed on Der f1 fecal allergen. Allergen reductions in carpet with two or five pass treatment regimes were 61.4 and 100%, respectively. These results demonstrate the potential of employing a hard surface steam cleaner as a novel method to eliminate house dust mite populations and their allergens in a residential setting and appeal particularly promising as an environmental control strategy.     

Skin tests and blood leukocyte histamine release of patients with allergies to laboratory animals

Skin tests and in vitro histamine-release reactions were used to evaluate 130 patients observed in an employee allergy clinic at a biomedical research facility. The allergens used included extracts from pollens (ragweed, grasses, trees, weeds), molds, mixed feathers, house dust, cat, dog, mouse, rat, rabbit, guinea pig, and hamster. Of all patients, 66% complained of allergic symptoms on laboratory animal exposure, although only 52% worked directly with animals. Among patients with symptoms, 91% were positive by skin test to at least one laboratory animal, and 46% had asthma. The median length of exposure to laboratory animals before onset of symptoms was 2.8 yr with 60% of the patients developing their symptoms within 3 yr. Among patients who had allergic symptoms before exposure to laboratory animals, 79% were skin test positive to laboratory animals when they were evaluated in this study. There was a close association found between the skin test and histamine-release results with the laboratory animal allergens: 91% of the 4+ skin reactors had leukocytes positive for histamine release versus 5% of the leukocyte donors with less than 1+ skin reactions. A close relationship in positive reactions to different laboratory animal allergens was also found. For example, individuals positive to mouse were positive also to rat (95%), rabbit (79%), guinea pig (83%), and hamster (88%). Patients who reacted to laboratory animals also reacted to some extent to house dust and cat and dog allergens, and about one half of the animal-allergic individuals reacted to pollens. Although nonpollen-allergic individuals can develop sensitivity to laboratory animals, the group at higher risk are allergic individuals, especially those sensitive to house dust, cats, or dogs.     

Specific IgE estimations by RAST in Japanese asthmatics compared with skin, passive transfer and bronchial provocation tests

198 asthmatics and twenty healthy persons were studied by RAST and in vivo tests with four common inhalant allergens, (a) Higher RAST classes were elicited with mite (Dermatophagoides farinae) extract and lower classes with other allergens. The agreement between positive RAST and skin or P-K tests was highest with the mite extract. RAST sensitivity was dependent on the kinds of allergens and was most sensitive to mite extract. Positive RAST was most closely related to the prick test reactions, (b) RASTs to house dust and mite extract were examined in terms of the threshold dosage of house dust and also the types of bronchial response (early, dual and late) induced by a certain amount of house dust; higher RAST classes were found in subjects with bronchial response of the dual or early type, elicited by a threshold dosage of diluted extract, while lower RAST classes were found in cases of the late-type response elicited by the threshold dosage of concentrated extract, (c) Changes in IgE antibodies to house dust and mite extract were estimated in patients with positive house dust provocation. A greater increase occurred in cases of dual or early response, a smaller increase in those with a late response. Despite discordances in skin tests and RAST between house dust and mite extracts, the increases in IgE antibodies to mite extracts as well as house dust were observed in all cases, presumably caused by an allergenic identity between the allergens.     

Exposure to house dust mite allergen of children admitted to hospital with asthma

Eighty-two children admitted to hospital with exacerbations of asthma were studied to determine how many were exposed to house dust mites at the time of admission and displayed immediate hypersensitivity to house dust mites. The concentration of house dust mite allergen (Der p I) was measured in dust obtained from the child's mattress, bedroom floor and living room floor. Sixty-two (75%) children admitted had been exposed to > 10 microg Der p I/g. Sixty-seven (82%) children were sensitive to house dust mite (RAST > or = 1 +, or weal > or = 3 mm): 49 (60%) children were both exposed and sensitive. In contrast in a control group of 44 children, 31 (70%) (n.s.) were exposed to > 10 microg Der p I/g, 10 (23%) (P<0.001) were sensitive to house dust mite, and 7 (16%) (P<0.001) were both exposed and sensitive. Seventy-three homes were revisited 6 months after the child's initial admission. During the preceding month 14 children had been readmitted, 12 were fully investigated; of these 10 were both sensitive to house dust mite and still exposed to > 10 microg Der p I/g. In contrast, of the remaining 62 children who were not readmitted, only 19 were both sensitive and still exposed to > 10 microg Der p I/g (P<0.001). In conclusion, the majority of children admitted to hospital with exacerbations of asthma were exposed to house dust mite allergen and were house dust mite sensitive. Further the results suggest that continued exposure to higher concentrations of mite allergen may be associated with the risk of readmission.     

Atopy in childhood. I. Gender and allergen related risks for development of hay fever and asthma

Reasons for the gender differences in prevalence rates for asthma remain unclear. We have examined the relationships between allergen skin-test reactions and diagnoses of hay fever and asthma in New Zealand boys and girls examined at the age of 13 years. Information on current and past wheezing, diagnosed asthma, and hay fever was obtained for 662 subjects (341 boys) of a birth cohort followed longitudinally to the age of 13 years, using a physician-administered questionnaire. Atopic status was determined by skin-prick tests to 11 common allergens. The proportion of 13-year-old boys with current asthma was 1.6 times higher and of ever-diagnosed asthma 1.4 times higher than in girls, but the prevalence of recurrent wheeze (> or = three episodes per year) not diagnosed as asthma, or of hay fever, was not significantly different between the sexes. The prevalence of diagnosed asthma increased with increasing numbers of positive skin tests, but hay fever without asthma was little affected above one positive skin-test. Boys had a greater prevalence of any positive skin-test (50.1% vs 37.1%), two or more positive tests (29.3% vs 21.8%), and responses to house dust mite (34.0% vs 23.1%) and cat (14.7% vs 11.2%). Gender differences for asthma became insignificant when adjusted for skin-test responsiveness to house dust mite and/or cat. The proportion of children with diagnosed asthma increased with increasing size of weals to house dust mite and cat dander. Gender differences in allergen sensitivities partly explain the gender differences in diagnosed asthma in children. In both sexes, risk of asthma was primarily associated with sensitization to indoor allergens (house dust mite and cat), and was related to the magnitude of the skin-test response, while the risk of hay fever was primarily associated with grass pollen sensitivity.     

Inhibition of human allergic skin reactions in vivo by pretreatment with cromolyn (disodium cromoglycate)

The effect of cromolyn on allergen-induced allergic skin reactions was studied. Two patients with allergic rhinitis, two patients with bronchial asthma and atopic dermatitis and two patients with allergic rhinitis and atopic dermatitis were included in this study. They were allergic to cedar pollen, house dust mite and house dust, respectively. Scratching with allergen induced wheal and erythema reactions in each patient. Simultaneous application of allergen and cromolyn solution did not modulate allergic reactions; however, pretreatment with cromolyn solution inhibited allergen-induced wheal and erythema reactions significantly.     

Influence of the Pollen Season on Immediate Skin Test Reactivity to Common Allergens

We studied the reproducibility of skin prick test reactions and tested 65 young men, picked from a population survey, in spring and fall. We used 16 extracts from two manufacturers with 12 common allergens. The extracts employed on both occasions were from the same allergen batches and the testing procedure was the same. Four subjects who reacted negatively in spring turned positive when retested in fall; the opposite happened to one subject. The result remained positive or negative on both occasions in 92%. The best reproducibility (96%) was obtained by pollens. The reactivity against tree and grass pollens was higher in fall than in spring; this is obviously a result of the immunologic stimuli induced by exposure to pollens during the season. The reactions caused by animal danders and house dust were, however, smaller in fall than in spring. This is believed to be due to young people being less exposed to indoor dusts in summer.
The immediate skin test reactivity is influenced by several factors; we would like to add one: the time of year when the test is applied. The reproducibility of skin prick test results is quite satisfactory when the problem is approached as presented here.     

Inhibition Experiments with Solid Phase Mite or Epithelia in House Dust Hypersensitivity

The present study was undertaken to verify that mites are not the only allergens in house dust extracts and that other allergens such as cat epithelia can also be responsible for house dust hypersensitivities detected both by house dust skin tests and house dust RAST studies. In order to determine whether mite or epithelia fixed on a solid phase could remove not only the IgE antibodies reactive with the homologous allergens, but also the IgE antibodies reactive with house dust allergens, the authors have absorbed 10 sera of house dust allergic patients with solid phase mite or epithelia. The absorption procedure removed a large part of the IgE antibodies reactive with specific immunosorbent (Dermatophagoides pteronyssinus or cat epithelia) and in the same way the IgE antibodies reactive with house dust immunosorbent. The percentage of RAST inhibition varied from 65% to 92% for Dermatophagoides pteronyssinus and from 65% to 94% for house dust in patients allergic to house dust and mite; the percentage of RAST inhibition varied from 67% to 92% for cat epithelia and from 73% to 90% for house dust in patients allergic to house dust and cat epithelia. This is in accordance with the hypothesis that house dust is not an allergen per se, but rather a complex mosaic of several allergens including mite, animal epithelia, etc.     

Distribution and determinants of house dust mite allergens in Europe: the European Community Respiratory Health Survey II

BACKGROUND: Several studies in European homes have described allergen levels from the house dust mite species Dermatophagoides pteronyssinus and to a lesser extent Dermatophagoides farinae, but geographic comparisons of exposure levels and risk factors have been hampered by a lack of standardized methods. OBJECTIVE: To study the distribution and determinants of the major house dust mite allergens Der p 1 and Der f 1 in 10 European countries using a common protocol. METHODS: During home visits with 3580 participants of the European Community Respiratory Health Survey II from 22 study centers, mattress dust was sampled and analyzed for Der p 1, Der f 1, and Der 2 allergen. Information on housing characteristics was obtained by both observations and interview. RESULTS: Der 1 and Der 2 allergens were detectable (>/=0.1 mug/g) in 68% and 53% of the samples, respectively. Large differences in allergen levels between study centers were observed, and geographic patterns for Der p 1 and Der f 1 were different. Low winter temperatures reduced Der p 1 rather than Der f 1. Important risk factors for high allergen levels included an older mattress, a lower floor level of the bedroom, limited ventilation of the bedroom, and dampness for Der p 1 but not for Der f 1. CONCLUSION: There are large qualitative and quantitative differences of house dust mite allergen levels in Europe, which can partly be explained by geographic and housing characteristics. CLINICAL IMPLICATIONS: Mite allergen exposure may be reduced by replacing the mattress regularly and increasing ventilation of the bedroom, particularly in winter.     

Wipe test for the detection of indoor allergens

BACKGROUND: The determination of house dust mite and cat allergens is a prerequisite for qualified assessment of exposure risk indoors. We describe the validation of integrated wipe tests comprising a porous sampling pin for the collection of settled house dust and an immunochemical test set-up for specific analysis of dust associated allergens. METHODS: Wipe tests comprised an immunochromatographic test system and a porous sampling pin for collecting dust by manually wiping a surface. Two different wipe tests were developed with specificity to cat allergen (Fel d 1) and to dust mite allergen (Der p 2/f 2). One-hundred and fifty on-site determinations for each of the allergens in 50 different households completed the field study to validate the analytical system. Reference analysis was based on collection of dust with a vacuum cleaner and analysis of dust associated allergens by ELISA. RESULTS: The wipe tests were found to produce semiquantitative results (class 0-3) on-site within 10 min of analysis time. For dust mite (cat) allergen the median of class 0-3 was 119 (263), 812 (844), 2708 (5670) and 8000 (56 800) ng/g dust, respectively. With respect to cut-off levels for dust mite (cat) allergens the clinical sensitivity was 62% (79%) and the clinical specificity was 94% (92%). CONCLUSIONS: The wipe tests proved to be a reliable tool for indoor allergen exposure screening, suitable for use even by untrained persons. This may have an impact on compliance with allergen avoidance measures.