Austrian children living on a farm have less hay fever, asthma and allergic sensitization

BACKGROUND AND OBJECTIVES: In some studies, the prevalence of hay fever and asthma has been found to be lower in children from rural areas than in children from an urban environment. We hypothesized that living on a farm might be protective against development of allergic sensitization and allergic diseases. METHODS: In a cross-sectional survey, parents of 2283 children aged 8-10 years from a mostly rural area in Austria answered a standardized questionnaire on allergic diseases and environmental factors. 1137 children performed a skin prick test to seven local allergens. RESULTS: The prevalence of hay fever (3.1 vs 10.3%, P = 0.0002), asthma (1.1 vs 3.9%, P = 0.017) and a positive skin prick reactivity to at least one of the common local allergens (18.8 vs 32.7%, P = 0. 001) was significantly lower in children living on a farm than in children from a non-farming environment. In a multivariate logistic regression model, adjusting for genetic background, parent education, living and housing conditions and dietary factors did not change the odds ratio for the association of farming and allergic sensitization. Only after including 'regular contact with livestock and poultry' into the model did the odds ratio change significantly (cOR 0.48 95% CI 0.30-0.75 to aOR 0.75 95% CI 0.37-1.52) indicating an association between regular contact with farm animals and reduced risk of atopic sensitization. CONCLUSION: Possible explanations for the lower prevalence of hay fever, asthma and allergic sensitization in children living on a farm might be the development of immunotolerance or the stimulation of TH1 cells and suppression of TH2 cells by increased exposure of farm children to microbial antigens in the stables or farmhouses.     

Association of hepatitis A virus infection with allergic sensitization in a population with high prevalence of hepatitis A virus exposure

BACKGROUND: An inverse association between allergic sensitization and markers of exposure to food-borne and orofecal infections (particularly hepatitis A virus, HAV) has been reported. The prevalence of HAV exposure and allergic sensitization vary widely in different areas, and vary along with age within a given area. AIM: To investigate the association between HAV exposure and allergic sensitization in adults from a mostly rural area of Spain. METHODS: An age-stratified random sample of 720 subjects was drawn from the population older than 18 years of A-Estrada, Spain. From 697 eligible subjects, 469 (67.2%, median age 54 years, range: 18-92) participated in the study. Positive skin prick tests to a panel of aeroallergens defined allergic sensitization. Positive serum HAV antibodies (assayed in 465 subjects) defined HAV exposure. RESULTS: The prevalence of HAV exposure was 83.6% (95% CI: 80.7-86.5). The prevalence of allergic sensitization was lower in subjects with HAV exposure than in patients without it (25.0%vs 40.0%, OR 0.44, 95% CI: 0.25-0.77, P=0.004), but this association became substantially altered after adjusting for age, which was closely linked to both allergic sensitization and HAV exposure (adjusted OR 1.15, 95% CI: 0.60-2.19, P=0.66). CONCLUSIONS: In a population with high prevalence of HAV exposure, no significant association between HAV exposure and allergic sensitization is observed after controlling for the confounding effect of age.     

The relationship between seroatopy and symptoms of either allergic rhinitis or asthma

BACKGROUND: Epidemiologic data on allergic rhinitis and asthma are frequently based on self-reported symptoms. OBJECTIVE: This cross-sectional study examined the relationship between self-reported symptoms and histories of allergic rhinitis or asthma and a marker of allergic sensitization, allergen-specific IgE. METHODS: We surveyed 702 pregnant women in Michigan. Blood samples were analyzed for specific IgE to 9 allergens: dust mites (Dermatophagoides farinae and Dermatophagoides pteronyssinus), cat, dog, cockroach, ragweed, timothy grass, egg, and Alternaria alternata. Seratopy was defined as a specific IgE greater than or equal to 0.35 kU/L to any allergen. RESULTS: Seroatopy was found in 66.7% of those with hay fever symptoms, 68.3% with a physician's diagnosis of asthma, and 72.1% of those with both conditions. These results differed significantly from asymptomatic subjects, where 49.8% of patients without hay fever and 50.4% without asthma were seroatopic. Race and education did not modify the relationships. Symptoms related to specific exposures were modest predictors of positive specific IgE to related allergens (positive predictive values from 26.5% to 50.3%). CONCLUSION: Self-reported symptoms of allergic rhinitis or asthma were significantly associated with allergic sensitization, but the odds ratios were of relatively low magnitude for this historical information to be considered evidence of current allergic sensitization. A 66% to 68% probability existed that those with symptoms of allergic rhinitis or asthma would have a positive specific IgE test. CLINICAL IMPLICATIONS: Self-reported histories of hay fever or asthma alone are only modest predictors of allergic sensitization. When knowledge of allergic sensitization is important, information beyond self-reported symptoms is necessary.     

Predictivity of allergic sensitization (RAST) for the onset of allergic diseases in adults

Background:  Specific IgE antibodies are often detected without any clinical manifestation of allergies. We aimed to analyse the predictivity of allergic sensitization for incident symptoms of allergic diseases in adults during a 10-year follow-up .
Methods:  In 1994/95 specific IgE antibodies against five common inhalant allergens (grass pollen, birch pollen, house dust mite, cat dander and Cladosporium ) were diagnosed by radioallergosorbent test in 4178 adults aged 25–74 years. A subset of 2656 participants could be re-evaluated in 2004/05. Information on socio-economic factors and medical history, including data on atopic diseases, was assessed by a combination of a personal interview and a self-administered questionnaire. Logistic regression models were applied to study associations between allergic sensitization and incident allergic diseases.
Results:  Allergic sensitization was an important predictor for incident hay fever (OR 7.95, CI 95% 4.64–13.62) and asthma (OR 1.82, CI 95% 1.29–2.57). Specific IgE antibodies were mainly related to outdoor allergens (grass and birch pollen) for hay fever and indoor allergens (mite and cat dander) for asthma, while for atopic dermatitis no specific IgE antibodies were identified as major predictors.
Conclusions:  Allergic sensitization not only covers clinically apparent allergies, but indicates a prognostic factor for later allergies, even in adulthood.     

Allergen-specific sensitization in asthma and allergic diseases in children: the study on farmers'' and non-farmers'' children

BACKGROUND: Farmers' children are less frequently sensitized to common allergens than the non-farmers' children, but less is known about their sensitization to other allergens and its association with clinical diseases. OBJECTIVE: To examine the association of farm environment with atopic sensitization, allergic diseases, expression of allergen-induced symptoms, and the importance of specific sensitization against 'common' (timothy, dog, cat, birch, Dermatophagoides pteronyssimus, mugwort) and 'other' (cockroach, horse, Lepidoglyphus destructor, cow) allergens for asthma and allergic diseases in children. METHODS: A cross-sectional study including 344 farmers' and 366 non-farmers' children aged 6-13 years in eastern Finland, using a self-administered written questionnaire and skin prick tests against the above-mentioned allergens. RESULTS: Farmers' children had less asthma and allergic diseases and were less often sensitized against common allergens than the non-farmers' children. However, little difference was observed in sensitization against the other allergens between the farmers' (17.2%) and non-farmers (14.5%) children [adjusted odds ratios (aOR) 1.11 (0.71-1.72)]. Being sensitized against only other allergens, without sensitization against common allergens, was unrelated to asthma or allergic diseases. Among the single allergens, sensitization against pets or pollen, or against horse or cow, had the strongest association with asthma, hayfever, and atopic eczema; no such association was seen in D. pteronyssimus, mugwort, cockroach, or L. destructor. Farmers' children had significantly less often symptoms of allergic rhinitis in contact with dog (aOR 0.32%, 95% confidence interval (CI) 0.15-0.67), cat (aOR 0.45, 0.22-0.88), or pollen (aOR 0.58%, 95% CI 0.37-0.90) than the non-farmers' children. CONCLUSION: Farm environment reduces the occurrence of asthma, allergic diseases, and atopic sensitization in children, and also the occurrence of allergen-induced rhinitis. Remarkable differences were observed between single allergens in their association with allergic disease, stressing the importance of allergen selection when defining atopy in epidemiological studies.     

Allergic sensitization to common airborne allergens among adults in Estonia

BACKGROUND: Allergies and asthma exhibit a growing health problem in the world. Sparse data are available about the prevalence of allergic sensitization in Estonia and Eastern Europe as well. We studied the prevalence of allergic sensitization, the associations between respiratory symptoms and allergic sensitization, and the influence of age, gender, area of residence, number of siblings and other demographic attributes on allergic sensitization in the population aged 17-69 years. METHODS: We conducted a cross-sectional study with 1,346 randomly selected participants distributed in 3 geographically and culturally distinct areas of Estonia. Sensitization to 15 aeroallergens was assessed by skin prick tests. The study also included a structured interview. RESULTS: The total prevalence of allergic sensitization was 33.0%. When estimated in patients aged 20-44 years, the prevalence was 38.5%. The most common sensitizer was cockroach followed by storage mites, while sensitization to cat, dog or pollen (common sensitizers in Scandinavian countries) was low. Allergic sensitization was significantly more common in urban and suburban compared with rural areas. Storage mites were the most common sensitizers in rural areas. Living in urban or suburban areas before the age of 5 significantly increased the risk for positive skin prick tests to several allergens. CONCLUSIONS: A higher prevalence of allergic sensitization than previously believed was found. Cockroach and storage mite allergens are suggested to be included in the routine investigation panel in Estonia.     

NAC Manchester Asthma and Allergy Study (NACMAAS): risk factors for asthma and allergic disorders in adults

Asthma and atopic disorders are the most common chronic diseases in the developed countries. Knowledge of the risk factors for these disorders may facilitate the development of preventive strategies aimed at reducing prevalence rates. To investigate the risk factors for asthma and allergic diseases in a large number of adults who are the parents of children in the National Asthma Campaign Manchester Asthma and Allergy Study. All pregnant women and their partners attending "Booking" antenatal clinics were invited to take part in the study. Questionnaire data were collected including the history of asthma and other atopic diseases, pet ownership and smoking habits, and skin prick tests were performed. The prevalence of atopy and the risk factors for asthma and allergic disorders were investigated in all subjects who completed the questionnaire and underwent skin testing. Statistical analysis was carried out using logistic regression. Initially, risk factors were assessed by univariate analysis to see how each potential explanatory variable affected the probability of having allergic disease. Variables were then tested in a forward stepwise multivariate analysis. In 5687 adult subjects there was a very high (48.2%) prevalence of atopy, and 9.7% of subjects had a diagnosis of asthma. In a multivariate regression analysis sensitization to dust mite, cat, dog and mixed grasses were all independently associated with asthma. The odds ratios for current asthma increased with the increasing number of positive skin tests (any two allergens - OR 4.3, 95% CI 3.3-5.5; any three allergens - OR 7.0 95% CI 5.3-9.3; all four allergens - OR 10.4, 95% CI 7.7-14; P < 0.00001). Dog ownership (OR 1.31, 95% CI 1.10-1.57; P = 0.003) and current smoking (OR 1.36, 95% CI 1.15-1.62; P = 0.0004) were significantly and directly associated with "asthma ever". Thirteen per cent of participants reported a history of eczema. In the multivariate analysis the strongest independent associate of eczema was sensitization to dog (OR 1.37, 95% CI 1.14-1.63, P < 0.0001). Apart from dog, the strength of the association between sensitization to common allergens and eczema appeared to be much lower than in the case of asthma. The prevalence of hay fever was high (20.6%), and in the multivariate analysis the association between sensitization to pollen and hay fever was extremely strong (OR 13.6, 95% CI 11.3-16.3; P < 0.0001). The results of the current study emphasize the importance of sensitization to indoor allergens in asthma. However, evidence of a possible direct role of allergen exposure in asthma causation remains unclear.     

Association between alcohol consumption and skin prick test reactivity to aeroallergens.

BACKGROUND: A few studies have indicated a positive association between consumption of alcohol and allergic sensitization in age and socioeconomically heterogeneous populations. OBJECTIVE: To investigate the association between consumption of alcohol and allergic sensitization in a young homogenous population of high social class (a group with a suspected high prevalence of sensitization). METHODS: A total of 1,668 students aged 18 to 35 years recruited from universities in Copenhagen, Denmark, underwent skin prick testing (SPT) in October or November 2002 and completed a questionnaire about respiratory disease and lifestyle habits, including alcohol consumption. SPT positivity was defined as a positive reaction (> or =3 mm) against at least 1 of 10 common inhalant allergens. RESULTS: Before and after adjustment for sex, age, smoking, atopic predisposition, and pet keeping, no significant association was found between alcohol consumption (including type of beverage) and SPT positivity. Increasing alcohol consumption was significantly negatively associated with asthma symptoms and hay fever symptoms. CONCLUSIONS: Alcohol consumption does not favor SPT positivity, but cumulated effects were not addressed in the present study. Individuals with asthma or hay fever symptoms seem to reduce alcohol intake (a healthy drinkers' effect).     

Skin prick-test reactivity to aeroallergens and allergic symptoms in an urban population of central Italy: a longitudinal study

BACKGROUND: Cross-sectional studies report an increasing prevalence of allergic diseases, such as rhinitis and asthma. Not thoroughly known, instead, is the natural history of allergic sensitization and the progress of the allergic disease-related symptoms. AIM: The purpose of this study was to evaluate longitudinally the skin reactivity for the most common aeroallergens and the allergic symptoms in an urban population living in Perugia, a town of central Italy with a low-level of air pollution exposure. METHODS: In the 1998-1999 period 788 subjects were tested for skin reactivity to a panel of aeroallergens and underwent the administration of a questionnaire. These same subjects were part of a cohort of 1200 subjects who participated in a previous epidemiological study performed in 1984-1985 using the same tools. Subjects were aged between 14 and 64 years at the time of the first survey. RESULTS: In the present survey 196 subjects (24.9%) had skin reactivity to at least one aeroallergen, while in the previous survey 143 subjects (18.1%) had skin prick-test reactivity. The increase of the skin reactivity between the two observations was highly significant (P<0.001) and was mainly observed in subjects <40-years old. The greatest increment in skin reactivity was seen to Dermatophagoides pteronyssinus (house dust mite) allergen. Data obtained from questionnaires showed that subjects who declared allergic symptoms increased from 341 (43.3%) to 380 (48.2%). However, the increase was significant (P<0.01) only in subjects who had a positive association between allergic symptoms and prick-test reactivity and was greater for rhino-conjunctivitis than for asthma-related symptoms. CONCLUSIONS: In a cohort of urban population of the centre of Italy, exposed to a low and stable level of air pollution, the sensitization to common aeroallergens increased with time, mostly in people <40-years of age. The greatest increment was found for indoor allergens such as Dermatophagoides pteronysimus. A significant increase in allergic symptoms, mainly related to rhino-conjunctivitis, was observed only in the presence of positive prick test.     

Allergic sensitization among adults in Tallinn, Estonia

BACKGROUND: The prevalence of allergic sensitization has increased worldwide during recent years. OBJECTIVE: The aim of the study was to estimate the prevalence of allergic sensitization and to evaluate the influence of age, gender, number of siblings, pet keeping in childhood, and residential area before the age of five on allergic sensitization among adolescents and adults aged 17-66 years in the capital of Estonia, Tallinn. A cross-sectional study was carried out between March 1997 and December 1998. METHODS: The sensitization to 15 inhalant allergens was assessed. The associations between sensitization based on skin prick tests (SPTs), symptoms based on a structured interview, and possible risk factors were estimated. A random sample of 516 subjects was included in the study analysis. RESULTS: The prevalence of allergic sensitization was 34.5%, while it was 39.3% in subjects aged 20-44 years. The most prevalent sensitization was against the German cockroach, 15.5%, and it was particularly high among adolescents. It was followed by mugwort, dog, two storage mites species, and cat dander. Subjects with wheezing during the last 12 months, attacks of shortness of breath, wheezing due to furred animals, and allergic rhinitis or conjunctivitis had a significantly higher prevalence of positive SPT. CONCLUSION: We found a surprisingly high prevalence of allergic sensitization among adults in Tallinn. Our results suggest that the cockroach allergen should be included in the investigation panel in order to reach a true prevalence of allergic sensitization in Estonia. Further, the pattern of allergic sensitization in Estonia appears to be different from published data about allergic sensitization in Scandinavia.     

Epidemiology of allergic occupational diseases induced by Tetranychus urticae in greenhouse and open-field farmers living in a temperate climate area

BACKGROUND: The role of Tetranychus urticae (TU) as an occupational allergen has thus far been investigated only in selected farmer samples. METHODS: The prevalence of TU-induced sensitization and occupational diseases in a randomized sample of farmers living in a temperate climate area was investigated. Occupational/nonoccupational symptoms, skin prick test (SPT) results with common allergens and TU, specific occupational test results, and greenhouse or open-field sources of TU exposure were assessed. The study design was cross-sectional. RESULTS: The prevalence of positive SPT to TU was 6%. TU-induced allergic/nonallergic complaints accounted for 65% of farmers with challenge-confirmed occupational disease. In all farmers, sensitization to common allergens was a risk factor for both current occupational and nonoccupational complaints, while TU sensitization was a prominent risk factor for occupational complaints. Furthermore, in SPT-positive farmers, only the presence of seasonal occupational complaints was significantly associated with TU sensitization. Common allergen sensitization was a risk factor for development of TU sensitization, which was more frequent in greenhouse than in open-field workers. CONCLUSIONS: TU was a common nontraumatic, allergic occupational hazard for farmers. Since occupational seasonal symptoms could be directly related to the presence of TU sensitization, allergy to this mite should be routinely investigated in farmers.     

Degree and clinical relevance of sensitization to common allergens among adults: a population study in Helsinki, Finland

BACKGROUND: We aimed to assess the prevalence of allergic sensitization and multiple sensitization, risk factors, and the clinical impact of being sensitized in the adult population of Helsinki, Finland. METHODS: As a part of the FinEsS study, a population-based random sample of 498 adults aged 26-60 years were tested for 15 common aeroallergens with skin prick tests (SPTs) and interviewed on respiratory symptoms and diseases, including respiratory irritants and childhood environment. RESULTS: The prevalence of at least one positive prick test was 46.9%. A large difference by age was found: 56.8% were sensitized among those aged 26-39 years, 49.2% in the age group 40-49 years, and 35.6% in the age group 50-60 years (P<0.001). Sensitization to multiple allergens was common among young subjects with 42% of the sensitized responding to at least four allergens, while this proportion was only 16% of the sensitized among those aged 50-60 years. The prevalence of physician-diagnosed asthma, allergic rhinitis (AR) or conjunctivitis, and wheeze increased significantly with increasing number of positive responses to SPTs. Having a family history of AR or conjunctivitis was a significant risk factor for allergic sensitization and for sensitization to any of the pollens. Further, urban living in childhood yielded an increased risk for pollen sensitization. CONCLUSIONS: The prevalence of allergic sensitization was high in the urban adult population of Helsinki. More than half of those aged 26-39 years was sensitized and 24% was sensitized to at least four allergens. Sensitization to multiple allergens was associated with a high prevalence of asthma, AR or conjunctivitis, and wheeze.     

Comparative degree and type of sensitization to common indoor and outdoor allergens in subjects with allergic rhinitis and/or asthma

Background and objectives The determinants of variability in the clinical expression of atopy are still to be documented. The goals of this study were to determine, in subjects with a clinical diagnosis of symptomatic asthma or rhinitis, what is the possible contribution of different types of indoor and outdoor allergens to the development of their disease, by looking at the prevalence and degree of sensitization to these allergens according to age and gender. Subjects and methods We analysed allergy skin prick tests to common airborne indoor and outdoor allergens in 3371 consecutive patients, grouped according to diagnosis of allergic asthma, rhinitis, or both. For each of these three groups, we calculated the prevalence of sensitization to indoor/outdoor allergens, the atopic index (Al), the number of positive responses to allergy skin prick test and the mean wheal diameter (MWD) of these responses. Results The prevalence of atopy and the values of Al and MWD peaked in subjects aged 16 to 25 years, declining afterwards; in subjects ± 18 years old, atopic indices were slightly higher in men than in women. In atopic subjects, the prevalence of sensitization was, in decreasing order: housedust (84.2%), cat hair-epithelium (76.5%), dog hair-dander (63.0%), house dust mite (54.2%), grasses (51.9%), trees (47.2%) and ragweed pollens (44.9%) and finally, moulds (25.4%). Among subjects sensitized only to outdoor allergens (n= 195), 73.8% had a rhinitis, 11.8% had asthma and 14.4% had both diagnoses; for those sensitized only to indoor allergens (n= 710), these values were respeetively 48.6, 24.5 and 26.9%, and for those sensitized to both indoor and outdoor allergens (n= 1793), the comparable values were 55.5, 14.6 and 29.9%. Conclusion These data show that in our population of subjects with respiratory allergic symptoms, indoor allergen sensitization is strongly associated with asthma, while exclusive sensitization to pollens is associated primarily with rhinitis. Sensitization was more prevalent for indoor allergens than for outdoor allergens in all groups determined according to diagnosis or age. Indices of atopy were higher in men in the group ± 18 years old. Prevalence and degree of sensitization were shown to peak in young adults, regardless of the allergen, and to diminish with age. This study stresses the role of indoor allergens in the development of asthma and shows the variability of allergic manifestations according to the type of sensitization.     

Prevalence of allergy, patterns of allergic sensitization and allergy risk factors in rural and urban children

BACKGROUND: We aimed to compare the prevalence of allergic diseases and sensitization in children living in urban and rural areas and to identify potential risk/protection factors associated with allergy. METHODS: School children 12-16 years old, from urban community (n = 201) and rural area (n = 203) were recruited. The data obtained by questionnaire were referred to doctors' diagnosis, skin prick tests (SPTs), and serum specific and total IgE assessment. RESULTS: The prevalence of allergic diseases in urban children was significantly higher as compared with rural children [asthma 16.42%vs 1.97% (P < 0.001) allergic rhinitis 38.81%vs 10.84% (P < 0.001)]. Positive SPTs to at least one allergen was found in 63.7% of urban and 22.7% rural children (P < 0.001). Significantly higher percentage of allergic rural than urban children were monosensitized or sensitized to 2-4 allergens, but almost a fourfold higher percentage of allergic urban children was found to be sensitized to five or more allergens (P < 0.0001). The history of frequent upper respiratory factor (URT) infections, antibiotic therapy, tonsiltectomy/adenoidectomy were positively associated with development of atopy and sensitization. CONCLUSION: Our findings confirm that residence of rural area is associated with a significant lower prevalence of allergic sensitization and symptoms in school children. Several risk and protective factors related to environment and style of life could be identified in both environments.     

Month of birth and allergic disease at the age of 10.

The relationship between month of birth and asthma, hay fever and skin sensitization to mixed grass pollen was analysed in a population-based cross-sectional study in Munich and Bavaria 1989-1990 of 6535 10-year-old children. The relative risk of developing atopic disease is calculated by comparing the prevalence in a single month with the prevalence of all other months. A slightly increased risk of developing allergic skin sensitization for grass pollen (n = 1128) was found for February (odds ratio, 1.3, 95% confidence interval 1.0-1.6), May (1.4, 1.1-1.8) and June (1.3, 1.0-1.6). For hay fever (n = 379) an increase was found for May (1.5, 1.0-2.1) and for allergic asthma (n = 277) for August (1.4, 1.0-2.1). A protective effect was observed for certain months of birth; September for allergic sensitization (0.8, 0.6-1.0), October for and November for hay fever (0.6, 0.3-0.9). The occurrence of hay fever and positive prick test is explained by the seasonal variation of atmospheric grass pollen and the peak in August of asthmatic patients by house dust. Date of birth appears therefore to slightly influence the risk of developing an allergic sensitization and allergic diseases.     

The association of hepatitis A and Helicobacter pylori with sensitization to common allergens, asthma and hay fever in a population of young British adults

BACKGROUND: A negative association of oro-faecally spread infection with serological markers of sensitization and allergic disease has been reported. METHOD: Previous infection with hepatitis A and Helicobacter pylori was assessed in a community-based sample of young British adults and associations with serum-specific IgE to environmental allergens, asthma-like symptoms and hay fever were examined. RESULTS: There was no association of previous infection with hepatitis A or H. pylori with wheeze or hay fever. There was no evidence of an association of infection with either agent and sensitization except for the isolated finding of a lower prevalence of sensitization to grass in those with IgG antibodies to H. pylori (OR 0.65, 95% CI 0.43-0.99). This association did not explain the negative association of family size with sensitization to grass. CONCLUSION: In this population, there was no evidence that infection with hepatitis A or H. pylori was associated with lower levels of IgE sensitization, asthma or hay fever except for an isolated finding of a negative association of H. pylori infection with sensitization to grass.     

Sensitivity and maximal response to methacholine in perennial and seasonal allergic rhinitis

Background Airway hyperresponsiveness to pharmacological agonists is a common feature in subjects with allergic rhinitis.
Objective The aim of this study was to investigate differences in threshold value and shape of the concentration-response curves to methacholine between subjects with perennial allergic rhinitis and subjects with seasonal rhinitis.
Methods We studied a sample of 72 non-asthmatic patients with allergic rhinitis. They were subdivided into two groups: subjects with only seasonal symptoms and skin sensitization to grass and/or Parietaria pollen allergens (seasonal group, n = 38), and subjects with perennial symptoms and skin sensitization to house dust mite, alone or with other allergens (perennial group, n = 34). They were challenged with methacholine (up to 200mg/mL), and concentration-response curves were characterized by the threshold value (PC₂₀= provocative concentration of methacholine required to produce a 20% fall in FEV₁) and maximal response plateau, if possible. The measurements in the seasonal group were done within the pollen season.
Results The geometric mean methacholine PC₂₀ for subjects of the perennial group was 6.9mg/mL, compared with 23.4mg/mL in subjects of the seasonal group ( P 0.01). A plateau response was detected in 16 subjects of the perennial group and in 28 subjects of the seasonal group (p 0.05). Moreover, the level of plateau was higher in subjects of the perennial group when compared with subjects of the seasonal group (23.8 ±2.0% vs 19.2 ±1.6%, P 0.05).
Conclusion In subjects with allergic rhinitis, sensitization to perennial allergens is associated not only with lower methacholine threshold values, but also with lower prevalence and higher level of plateau than sensitization to pollen allergens.     

Exposure and allergic sensitization to cockroach allergen in East Germany

BACKGROUND: Some studies suggest that the prevalence of sensitization to cockroach allergens may be higher in the United States than in Europe, but there are no comparable data from population-based studies. OBJECTIVES: To determine the prevalence of allergic sensitization to German cockroach (GCR) in German schoolchildren and to assess its clinical relevance; and to determine the exposure to the major GCR allergen Bla g 2 in non-selected homes and nurseries. METHODS: The prevalence of allergic sensitization to GCR and other allergens was determined by measurement of specific IgE and skin-prick tests in a cross-sectional study of 2993 children aged 5-11 years in Dresden, Germany. The prevalence of atopic disease was determined by questionnaire, and pulmonary function and bronchial hyperresponsiveness to hypertonic saline were measured. Bla g 2 exposure was determined on floors of 187 kitchens and 47 nurseries by a commercial sandwich ELISA. RESULTS: One hundred and twenty-seven (4.2%) of the children had specific IgE (> 0.7 kU/L) against GCR. Among children with current wheeze, 8.4% were GCR-sensitized. Compared to data from the United States, the prevalence of sensitization to cockroach was similar in children without asthma (3.9%), but less frequent in asthmatic children from Dresden (6.1%). After adjustment for positive reactions to other allergens (SX1 test) no significant impact of GCR sensitization on wheeze or other symptoms and diagnoses was found. Bla g 2 was detected in 29% of the kitchens and 43% of the nurseries. None of these sites had exposure levels above the proposed threshold for causing disease of 80 ng/g dust. CONCLUSION: The data suggest that allergic sensitization to GCR is less frequent in asthmatics from Dresden, Germany than in US cities. The data indicate that GCR sensitization is not an independent risk factor for asthma and other atopic diseases in 5-11-year-olds from this city.     

Dichotomy of food and inhalant allergen sensitization in eosinophilic esophagitis

BACKGROUND: Eosinophilic esophagitis (EE) is an emerging condition where patients commonly present with symptoms of gastroesophageal reflux disease and fail to respond adequately to anti-reflux therapy. Food allergy is currently recognized as the main immunological cause of EE; recent evidence suggests an etiological role for inhalant allergens. The presence of EE appears to be associated with other atopic illnesses. OBJECTIVES: To report the sensitization profile of both food and inhalant allergens in our EE patient cohort in relation to age, and to profile the prevalence of other allergic conditions in patients with EE. METHOD: The study prospectively analyzed allergen sensitization profiles using skin prick tests to common food allergens and inhalant allergens in 45 children with EE. Patch testing to common food allergens was performed on 33 patients in the same cohort. Comorbidity of atopic eczema, asthma, allergic rhinitis and anaphylaxis were obtained from patient history. RESULTS: Younger patients with EE showed more IgE and patch sensitization to foods while older patients showed greater IgE sensitization to inhalant allergens. The prevalence of atopic eczema, allergic rhinitis and asthma was significantly increased in our EE cohort compared with the general Australian population. A total of 24% of our cohort of patients with EE had a history of anaphylaxis. CONCLUSION: In children with EE, the sensitization to inhalant allergens increases with age, particularly after 4 years. Also, specific enquiry about severe food reactions in patients presenting with EE is strongly recommended as it appears this patient group has a high incidence of anaphylaxis.     

Impact of cross‐reactive carbohydrate determinants on wood dust sensitization

Background Occupational wood dust exposure can induce allergy and may be one cause of respiratory health problems among woodworkers. Objective The objective was to determine the prevalence and quantitative level of specific immunoglobulin E (sIgE) to beech and pine wood in exposed workers. Wood sensitization was specified with regard to cross‐reactivity and was correlated to the reported symptoms. Methods Danish workers (n=701) were investigated for sIgE to beech and pine. Wood samples from workplaces were analysed and coupled to ImmunoCAPs. Workers sensitized to wood were tested for cross‐reactive carbohydrate determinants (CCDs) and environmental allergens. IgE binding was specified for glycogenic vs. proteinogenic epitopes by inhibition tests. Results The prevalence of wood sensitization among all workers was 3.7%. There was no association between sensitization prevalence or sIgE concentrations and self‐reported allergic symptoms. Beech‐ and pine‐sensitized workers showed a high prevalence of CCD sensitization (73%). However, workers with a single sensitization to wood had no sIgE to CCDs. Specifying IgE epitopes demonstrated that sera of workers reporting allergic symptoms recognized proteinogenic IgE‐epitopes on wood allergens, whereas workers without allergic symptoms had primarily sIgE‐epitopes to glycogenic structures. Although 96% of the wood‐sensitized workers were atopic, no significant correlation was found between wood sensitization and sIgE to beech and birch pollen, but an association was found between sIgE against CCDs and pine pollen. Conclusion Sensitization prevalence to beech and pine wood measured by tailored ImmunoCAPs was not correlated to allergic symptoms. We recommend the application of CCD tools to assess the relevance of individual wood sensitization. Cite this as: S. Kespohl, V. Schlünssen, G. Jacobsen, I. Schaumburg, S. Maryska, U. Meurer, T. Brüning, T. Sigsgaard and M. Raulf‐Heimsoth, Clinical & Experimental Allergy, 2010 (40) 1099–1106.