A European-Japanese study on peach allergy: IgE to Pru p 7 associates with severity.

BACKGROUND: Pru p 3 and Pru p 7 have been implicated as risk factors for severe peach allergy. This study aimed to establish sensitization patterns to five peach components across Europe and in Japan, to explore their relation to pollen and foods and to predict symptom severity. METHODS: In twelve European (EuroPrevall project) and one Japanese outpatient clinic, a standardized clinical evaluation was conducted in 1231 patients who reported symptoms to peach and/or were sensitized to peach. Specific IgE against Pru p 1, 2, 3, 4 and 7 and against Cup s 7 was measured in 474 of them. Univariable and multivariable Lasso regression was applied to identify combinations of parameters predicting severity. RESULTS: Sensitization to Pru p 3 dominated in Southern Europe but was also quite common in Northern and Central Europe. Sensitization to Pru p 7 was low and variable in the European centers but very dominant in Japan. Severity could be predicted by a model combining age of onset of peach allergy, probable mugwort, Parietaria pollen and latex allergy, and sensitization to Japanese cedar pollen, Pru p 4 and Pru p 7 which resulted in an AUC of 0.73 (95% CI 0.73-0.74). Pru p 3 tended to be a risk factor in South Europe only. CONCLUSIONS: Pru p 7 was confirmed as a significant risk factor for severe peach allergy in Europe and Japan. Combining outcomes from clinical and demographic background with serology resulted in a model that could better predict severity than CRD alone.

Component-resolved diagnosis and beyond: Multivariable regression models to predict severity of hazelnut allergy.

BACKGROUND: Component-resolved diagnosis (CRD) has revealed significant associations between IgE against individual allergens and severity of hazelnut allergy. Less attention has been given to combining them with clinical factors in predicting severity. AIM: To analyze associations between severity and sensitization patterns, patient characteristics and clinical history, and to develop models to improve predictive accuracy. METHODS: Patients reporting hazelnut allergy (n = 423) from 12 European cities were tested for IgE against individual hazelnut allergens. Symptoms (reported and during Double-blind placebo-controlled food challenge [DBPCFC]) were categorized in mild, moderate, and severe. Multiple regression models to predict severity were generated from clinical factors and sensitization patterns (CRD- and extract-based). Odds ratios (ORs) and areas under receiver-operating characteristic (ROC) curves (AUCs) were used to evaluate their predictive value. RESULTS: Cor a 9 and 14 were positively (OR 10.5 and 10.1, respectively), and Cor a 1 negatively (OR 0.14) associated with severe symptoms during DBPCFC, with AUCs of 0.70-073. Combining Cor a 1 and 9 improved this to 0.76. A model using a combination of atopic dermatitis (risk), pollen allergy (protection), IgE against Cor a 14 (risk) and walnut (risk) increased the AUC to 0.91. At 92% sensitivity, the specificity was 76.3%, and the positive and negative predictive values 62.2% and 95.7%, respectively. For reported symptoms, associations and generated models proved to be almost identical but weaker. CONCLUSION: A model combining CRD with clinical background and extract-based serology is superior to CRD alone in assessing the risk of severe reactions to hazelnut, particular in ruling out severe reactions.

The EuroPrevall outpatient clinic study on food allergy: background and methodology.

BACKGROUND: The EuroPrevall project aimed to develop effective management strategies in food allergy through a suite of interconnected studies and a multidisciplinary integrated approach. To address some of the gaps in food allergy diagnosis, allergen risk management and socio-economic impact and to complement the EuroPrevall population-based surveys, a cross-sectional study in 12 outpatient clinics across Europe was conducted. We describe the study protocol. METHODS: Patients referred for immediate food adverse reactions underwent a consistent and standardized allergy work-up that comprised collection of medical history; assessment of sensitization to 24 foods, 14 inhalant allergens and 55 allergenic molecules; and confirmation of clinical reactivity and food thresholds by standardized double-blind placebo-controlled food challenges (DBPCFCs) to milk, egg, fish, shrimp, peanut, hazelnut, celeriac, apple and peach. RESULTS: A standardized methodology for a comprehensive evaluation of food allergy was developed and implemented in 12 outpatient clinics across Europe. A total of 2121 patients (22.6% <14 years) reporting 8257 reactions to foods were studied, and 516 DBPCFCs were performed. CONCLUSIONS: This is the largest multicentre European case series in food allergy, in which subjects underwent a comprehensive, uniform and standardized evaluation including DBPCFC, by a methodology which is made available for further studies in food allergy. The analysis of this population will provide information on the different phenotypes of food allergy across Europe, will allow to validate novel in vitro diagnostic tests, to establish threshold values for major allergenic foods and to analyse the socio-economic impact of food allergy.

Pleistocene genetic legacy suggests incipient species of Sebastes mentella in the Irminger Sea.

To investigate a possible speciation event within the redfish (Sebastes mentella) complex in the Irminger Sea, we examined genetics, traditional morphology, geometric morphometrics and meristics of individuals sampled throughout the Sea. Tissue samples from 1901 fish were collected in 1995 and 1996 and from 1999 to 2002, and the fish were genotyped at nine microsatellite loci, two of which were developed for this study. Individual-based genetic analyses showed that two different gene pools exist in the Irminger Sea. Although these groups overlap extensively geographically, they segregate according to depth: those above and below 550 m. This signal of genotype distinction with depth was evident in both the earlier and later sampling. Historical imprints in the genetic data indicated that the redfish in the Irminger Sea are likely to represent a case of an incipient speciation event that began in allopatry during the Pleistocene glaciations followed by secondary contact. Although hybridization was observed between groups, an analysis of traditional and geometric morphometrics and of meristic variables suggested that restricted gene flow between the currently parapatric deep- and shallow-mesopelagic incipient species may be maintained by ecological isolation mechanisms.

The socio-economic burden of asthma is substantial in Europe.

BACKGROUND: Few data are available on the asthma burden in the general population. We evaluated the level and the factors associated with the asthma burden in Europe. METHODS: In 1999-2002, 1152 adult asthmatics were identified in the European Community Respiratory Health Survey (ECRHS)-II and the socio-economic burden (reduced activity days and hospital services utilization in the past 12 months) was assessed. RESULTS: The asthmatics with a light burden (only a few reduced activity days) were 13.2% (95% CI: 11.4-15.3%), whereas those with a heavy burden (many reduced activity days and/or hospital services utilization) were 14.0% (95% CI: 12.1-16.1%). The burden was strongly associated with disease severity and a lower quality of life. Obese asthmatics had a significantly increased risk of a light [relative risk ratio (RRR) = 2.17; 95% CI: 1.18-4.00] or a heavy burden (RRR = 2.77; 95% CI: 1.52-5.05) compared with normal/underweight subjects. The asthmatics with frequent respiratory symptoms showed a threefold (RRR = 2.74; 95% CI: 1.63-4.61) and sixfold (RRR = 5.76; 95% CI: 3.25-10.20) increased risk of a light or a heavy burden compared with asymptomatic asthmatics, respectively. Moreover, the lower the forced expiratory volume in 1 s % predicted, the higher the risk of a heavy burden. The coexistence with chronic cough/phlegm only increased the risk of a heavy burden (RRR = 1.88; 95% CI: 1.16-3.06). An interaction was found between gender and IgE sensitization, with nonatopic asthmatic females showing the highest risk of a heavy burden (21.6%; 95% CI: 16.9-27.1%). CONCLUSIONS: The asthma burden is substantial in Europe. A heavy burden is more common in asthmatics with obesity, frequent respiratory symptoms, low lung function, chronic cough/phlegm and in nonatopic females.

Eczema, atopy and allergen exposure in adults: a population-based study.

BACKGROUND: There are few published studies on geographical variation in prevalence of eczema in adults or its association with recognised risk factors for allergic disease. OBJECTIVE: To describe the geographical variation in prevalence of eczema in adults, assess the associations with sociodemographic risk factors, serum-specific IgE and IgG, and exposure to allergen. METHODS: A community-based sample of 8206 adults aged 27-56 years, in 25 European centres and Portland, USA, provided questionnaire information on symptoms of eczema. Serum-specific IgE to house dust mite (HDM), cat, grass and Cladosporium, and IgG and IgG4 to HDM and cat were measured. Mattress levels of mite and cat allergen were assessed. RESULTS: Overall prevalence of eczema was 7.1% (range between countries of 2.2-17.6%). Eczema was associated with female gender [odds ratio (OR) 1.25; 95% confidence interval (CI) (1.01-1.55)], family history of atopic disease (OR 1.43; 95% CI 1.18-1.74), IgE sensitization to at least one allergen (OR 1.50; 95% CI 1.19-1.90), particularly Cladosporium (OR 3.65; 95% CI 1.81-7.37), and total IgE. Eczema was negatively associated with age and no clear associations were observed with sibship size, mattress mite and cat allergen levels or with cat and HDM-specific IgG or IgG4. CONCLUSIONS: There is geographical variation in the prevalence of eczema in adults both within and between countries. Although the disease is associated with IgE sensitization, in this study it was not related to mattress mite or cat allergen levels.

Prevalence and incidence of respiratory symptoms in relation to indoor dampness: the RHINE study.

BACKGROUND: An association between indoor dampness and respiratory symptoms has been reported, but dampness as a risk factor for the onset or remission of respiratory symptoms and asthma is not well documented. METHOD: This follow up study included 16 190 subjects from Iceland, Norway, Sweden, Denmark, and Estonia who had participated in the European Community Respiratory Health Survey (ECRHS I). Eight years later the same subjects answered a postal questionnaire that included questions on respiratory symptoms and indicators of indoor dampness. RESULTS: Subjects living in damp housing (18%) had a significantly (p<0.001) higher prevalence of wheeze (19.1% v 26.0%), nocturnal breathlessness (4.4% v 8.4%), nocturnal cough (27.2% v 36.5%), productive cough (16.6% v 22.3%) and asthma (6.0% v 7.7%). These associations remained significant after adjusting for possible confounders. Indoor dampness was a risk factor for onset of respiratory symptoms but not for asthma onset in the longitudinal analysis (OR 1.13, 95% CI 0.92 to 1.40). Remission of nocturnal symptoms was less common in damp homes (OR 0.84, 95% CI 0.73 to 0.97). CONCLUSIONS: Subjects living in damp housing had a higher prevalence of respiratory symptoms and asthma. Onset of respiratory symptoms was more common and remission of nocturnal respiratory symptoms was less common in subjects living in damp housing.

Hormone replacement therapy, body mass index and asthma in perimenopausal women: a cross sectional survey.

BACKGROUND: Hormone replacement therapy (HRT) and obesity both appear to increase the risk of asthma. A study was undertaken to investigate the association of HRT with asthma and hay fever in a population of perimenopausal women, focusing on a possible interaction with body mass index (BMI). METHODS: A postal questionnaire was sent to population based samples in Denmark, Estonia, Iceland, Norway, and Sweden in 1999-2001, and 8588 women aged 25-54 years responded (77%). Pregnant women, women using oral contraceptives, and women <46 years were excluded. Analyses included 2206 women aged 46-54 years of which 884 were menopausal and 540 used HRT. Stratified analyses by BMI in tertiles were performed. RESULTS: HRT was associated with an increased risk for asthma (OR 1.57 (95% CI 1.07 to 2.30)), wheeze (OR 1.60 (95% CI 1.22 to 2.10)), and hay fever (OR 1.48 (95% CI 1.15 to 1.90)). The associations with asthma and wheeze were significantly stronger among women with BMI in the lower tertile (asthma OR 2.41 (95% CI 1.21 to 4.77); wheeze OR 2.04 (95% CI 1.23 to 3.36)) than in heavier women (asthma: p(interaction) = 0.030; wheeze: p(interaction) = 0.042). Increasing BMI was associated with more asthma (OR 1.08 (95% CI 1.05 to 1.12) per kg/m2). This effect was only found in women not taking HRT (OR 1.10 (95% CI 1.05 to 1.14) per kg/m2); no such association was detected in HRT users (OR 1.00 (95% CI 0.92 to 1.08) per kg/m2) (p(interaction) = 0.046). Menopause was not significantly associated with asthma, wheeze, or hay fever. CONCLUSIONS: In perimenopausal women there is an interaction between HRT and BMI in the effects on asthma. Lean women who were HRT users had as high a risk for asthma as overweight women not taking HRT. It is suggested that HRT and overweight increase the risk of asthma through partly common pathways.

Changes in the use of anti-asthmatic medication in an international cohort.

The aim of this study was to describe changes in pharmacotherapy for asthma since the early 1990s in an international cohort of young and middle-aged adults. A total of 28 centres from 14 countries participated in a longitudinal study. The study included 8,829 subjects with a mean follow-up time of 8.7 yrs. Change in the prevalence of use for medication was expressed as absolute net change (95% confidence interval) standardised to a 10-yr period. The use of anti-asthmatics was found to have increased by 3.1% (2.4-3.7%) and the prevalence of symptomatic asthma by 4.0% (3.5-4.5%). In the sample with asthma in both surveys (n=423), the use of inhaled corticosteroids increased by 12.2% (6.6-17.8%). Despite this, only 17.2% were using inhaled corticosteroids on a daily basis at follow-up. Females with continuous asthma were more likely, compared with males, and smokers with asthma, to have started using inhaled corticosteroids since the first survey. The use of anti-asthmatics has increased in a pattern consistent with current consensus on treatment. However, despite increased use of inhaled corticosteroids, a large majority of subjects with symptomatic asthma do not use this treatment on a daily basis, particularly males and smokers with asthma.

C reactive protein levels are increased in non-allergic but not allergic asthma: a multicentre epidemiological study.

BACKGROUND: High sensitivity C reactive protein (HsCRP) is an inflammatory marker known to be related to smoking, obesity, and cardiovascular disease. A study was undertaken to determine whether HsCRP is related to respiratory symptoms, asthma, atopy, and bronchial hyperresponsiveness in population samples from three countries. METHODS: HsCRP was measured in 1289 subjects from three centres in ECRHS II: Reykjavik, Uppsala and Tartu. The HsCRP values ranged from <0.01 mg/l to 70.0 mg/l and were divided into four equal groups (< or = 0.45, 0.46-0.96, 0.97-2.21, and >2.21 mg/l). RESULTS: HsCRP increased with increasing body mass index (r = 0.41; p<0.0001) and was higher in smokers than in never smokers (p = 0.02). A significant relationship was found between increased HsCRP levels and respiratory symptoms such as wheeze, attacks of breathlessness after effort, and nocturnal cough (p<0.0001). The crude odds ratio (95% CI) for the probability of non-allergic asthma was 3.57 (1.83 to 6.96) for subjects in the 4th quartile compared with the 1st quartile of HsCRP. This association remained significant after adjusting for study centre, age, sex, body weight, and smoking history (OR 2.19 (95% CI 1.04 to 4.63)). No significant relationship was observed between HsCRP and allergic asthma or bronchial responsiveness. CONCLUSIONS: Raised levels of HsCRP are significantly associated with respiratory symptoms and non-allergic asthma but not with allergic asthma.

Obesity and nocturnal gastro-oesophageal reflux are related to onset of asthma and respiratory symptoms.

Several studies have identified obesity as a risk factor for asthma in both children and adults. An increased prevalence of asthma in subjects with gastro-oesophageal reflux (GOR) and obstructive sleep apnoea syndrome has also been reported. The aim of this investigation was to study obesity, nocturnal GOR and snoring as independent risk factors for onset of asthma and respiratory symptoms in a Nordic population. In a 5-10 yr follow-up study of the European Community Respiratory Health Survey in Iceland, Norway, Denmark, Sweden and Estonia, a postal questionnaire was sent to previous respondents. A total of 16,191 participants responded to the questionnaire. Reported onset of asthma, wheeze and night-time symptoms as well as nocturnal GOR and habitual snoring increased in prevalence along with the increase in body mass index (BMI). After adjusting for nocturnal GOR, habitual snoring and other confounders, obesity (BMI >30) remained significantly related to the onset of asthma, wheeze and night-time symptoms. Nocturnal GOR was independently related to the onset of asthma and in addition, both nocturnal GOR and habitual snoring were independently related to onset of wheeze and night-time symptoms. This study adds evidence to an independent relationship between obesity, nocturnal gastro-oesophageal reflux and habitual snoring and the onset of asthma and respiratory symptoms in adults.

Population genetic structure of Arctic charr, Salvelinus alpinus from northwest Europe on large and small spatial scales.

To examine the population genetic structure of lake-resident Arctic charr, Salvelinus alpinus from northwest Europe on multiple spatial scales, 2367 individuals from 43 lakes located in three geographical regions (Iceland, the British Isles and Scandinavia) were genotyped at six microsatellite loci. On a large scale, data provided little evidence to support clustering of populations according to geographical region. Hierarchical analysis of molecular variance indicated that, although statistically significant, only 2.17% of the variance in allelic frequencies was partitioned at the among-region level. Within regions, high levels of genetic differentiation were typically found between lakes regardless of the geographical distance separating them. These results are consistent with the hypothesis of rapid postglacial recolonization of all of northwest Europe from a single charr lineage, with subsequent restriction of gene flow. On a smaller scale, there was evidence for close genetic relationships among lakes from within common drainage basins in Scotland. Thus, interlake genetic structure reflects localized patterns of recent (or contemporary) gene flow superimposed onto a larger scale structure that is largely a result of historical processes. There was also evidence for widespread genetic structuring at the within-lake level, with sympatric populations detected in 10 lakes, and multilocus heterozygote deficits found in 23 lakes. This evidence of the Wahlund effect was found in all lakes known to contain discrete phenotypic morphs, as well as many others, suggesting that morphs may often represent separate breeding populations, and also that the phenomenon of polymorphism in this species may be more widespread than is currently realized.

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.

Allelic frequencies and patterns of single-nucleotide polymorphisms in candidate genes for asthma and atopy in Iceland.

Numerous asthma and atopy loci have been reported in studies demonstrating associations of the asthma-related phenotypes atopy, elevated IgE levels, and bronchial hyperresponsiveness with alleles of microsatellite markers and single-nucleotide polymorphisms (SNPs) within specific cytokine/chemokine and IgE-regulating genes. Although the studies reporting these observations are compelling, most of them lack statistical power. We assessed the nature, pattern, and frequency of SNPs in 24 candidate genes in Iceland and looked for associations with asthma and atopy. We identified 42 SNPs with an average minor allele frequency of 20.3% (asthma) and 20.7% (control). Twenty SNPs (48%) were within coding sequences and 90% of those led to a predicted change in protein sequence. No differences were detected in the allelic frequencies of SNPs in any of these candidate genes between control subjects and the patients with atopic asthma. Moreover, linkage analysis that included 269 patients with atopic asthma uncovered no evidence of linkage to markers associated with these genes. We conclude that this study has failed to produce evidence in support of the notion that variations within these 24 candidate atopy and asthma genes significantly influence the expression of the atopic asthmatic phenotype or contribute to the susceptibility of atopic asthma.

[Atopy and allergic disorders among Icelandic medical students.].

OBJECTIVE: To compare the prevalence of IgE-mediated sensitization, allergic disorders and possible risk factors for atopic sensitization among Icelandic medical students (n=113) to a randomly chosen age matched group previously investigated in the Icelandic part of the European Community Respiratory Health Survey. MATERIAL AND METHODS: Altogether 100 medical students participated and 102 in the control group. They were skin prick tested and they answered questions about respiratory symptoms, smoking habits, family history and home environment in childhood. RESULTS: Only 4% of medical students reported daily smoking compared to 27% of the controls. The medical students also had a significantly lower number (mean +/- SD) of siblings (2.2+/-1.3) compared to the controls (3.9+/-1.7). The controls also shared bedrooms with older siblings in childhood three times as often. Atopic sensitization, defined as a positive (3 mm or more) reaction to at least one of nine common airborne allergens used in testing, was found in 41% of the medical students compared to 26.5% of the controls. The prevalence of asthma and urticaria was also significantly higher among the medical students. CONCLUSIONS: Medical students have more often IgE-mediated sensitization and allergy related diseases than a controlgroup of the same age. A possible explanation to this is a lower number of siblings among medical students and a different household situation in childhood.

[Allergy and intolerance to food in an Icelandic urban population 20-44 years of age.].

OBJECTIVE: Symptoms related to the intake of certain food items are common. In most of these cases food allergy/intolerance can not be confirmed. In the Icelandic part of the European Community Respiratory Health Survey the prevalence of food-related symptoms was assessed among adult Icelanders. MATERIAL AND METHODS: Three thousand and six hundred men and women, 20-44 years, were studied, among them 800 were randomly chosen for a more detailed investigation. Additionally, all those using asthma medication or having asthma symptoms were investigated. A questionnaire inquired about chest symptoms, symptoms related to food-intake and eating habits. In Iceland additional questions were asked concerning drug intolerance, urticaria, Quincke oedema, childhood eczema, migraine and psoriasis. All subjects underwent skin prick tests against 12 common allergens, spirometry and methacholine challenge. Specific IgE antibodies against five airborne allergens and six common food allergens were measured. RESULTS: Among subjects with food-related symptoms, 68% reported complaints from the GI-tract, 22% had skin rash or pruritus, 15% severe headache, 11% breathlessness, 8% a running/stuffy nose and 4% fatique. Altogether 42 food items were considered likely causes of the reported symptoms. Twenty-two percent of the random sample had symptoms related to the intake of a particular food and 15% reported always having the same symptom after intake of this food. Women reported food-related symptoms somewhat more often that men (17% and 13% respectively (p=0.21)). In the random sample only 1.8% had antibodies to one or more of the foods measured. There was a significant relationship between food-related symptoms and reported migraine, urticaria and Quincke oedema and a particularily strong relationship with drug intolerance. Migraine, urticaria, Quincke oedema and drug intolerance were significantly more common among women (p<0.0001, p<0.01, p<0.05 and <0.002 respectively). No relationship was seen between food-related symptoms and positive methacholine tests. CONCLUSIONS: In conclusion this study reveales a large group of subjects reporting food-releated symptoms. This group also reported a big prevalence of unrelated symptoms such as drug intolerance and migraine. Type-1 allergy is unlikely to be the cause to more than a small part of these symptoms.

Sensitization to airborne and food allergens in Reykjavík (Iceland) and Uppsala (Sweden) - a comparative study.

BACKGROUND: The aim of this study was to compare the prevalence of atopic sensitization and possible risk factors for allergies in two ethnically similar but geographically widely separated urban populations. METHODS: Data from two centers of the European Community Respiratory Health Survey, Reykjavik, Iceland, and Uppsala, Sweden, were utilized. This included a structured interview, skin prick tests, and blood samples for total and specific IgE for common aeroallergens. Additional measurements of specific IgE antibodies to common food antigens were performed. Furthermore, data on social environment, lifestyle, air pollution, and meteorologic variables were compared. RESULTS: Skin prick tests were done on 540 individuals in Reykjavik and 527 in Uppsala. The overall prevalence of at least one positive prick test was 20.5% in Reykjavik and 34.2% in Uppsala (P<0.001). Total and specific IgE were measured in serum from 521 subjects in Reykjavik and 472 in Uppsala. The geometric mean value for total IgE was significantly lower in Reykjavik (13.4 kU/l) than in Uppsala (24.7 kU/l) (P<0.001). Similarly, the overall prevalence of at least one specific IgE to airborne allergens was 23.6% in Reykjavik and 32.3% in Uppsala (P<0.01). Specific IgE to a food panel (fx5) was measured in 502 subjects in Reykjavik, and 434 in Uppsala. In Reykjavik, 20 individuals (4.0%) were positive to one or more of the allergens in the food panel compared to 27 (6.0%) in Uppsala. When the single allergens present in the food panel were measured, altogether 16 positive reactions were found in Reykjavik compared to 47 in Uppsala (P<0.05). CONCLUSIONS: The prevalence of sensitization to both airborne and food allergens was lower in Reykjavik than in Uppsala. The difference may be due to environmental and/or dietary differences or to some yet undefined factor.

IgE-mediated allergy to Lepidoglyphus destructor in an urban population--an epidemiologic study.

BACKGROUND: The aim of this study was to estimate the prevalence of IgE-mediated allergy to Lepidoglyphus destructor and its clinical importance in Reykjavik, Iceland. METHODS: All Icelandic participants in the European Community Respiratory Health Survey in Reykjavik and suburbs were skin prick tested (SPT) for L. destructor. They also participated in a structured interview including questions about exposure to hay and symptoms related to hay exposure. Spirometry and methacholine tests were also performed. RESULTS: Altogether, 540 individuals underwent SPT with 12 allergens. Among them, 137 (25.4%) had positive skin tests, defined as at least one mean wheal reaction of > or =1 mm. By this definition, 34 (6.3%) were positive to L. destructor. These 34 individuals were significantly (P < 0.001) more often allergic to D. pteronyssinus (24/34), grass (14/34), cat (13/34), dog (12/34), Alternaria (11/34), Cladosporium (9/34), horse (8/34), and olive (8/34) than those not allergic to L. destructor. Those SPT positive to L. destructor had a higher total IgE (geometric mean: 40.9 kU/I vs 12.3 kU/I, P < 0.001) than those who were negative to L. destructor, but their lung function was comparable to that of the others. Asthma during the preceding 12 months or asthma ever suffered was not overrepresented among those SPT-positive to L. destructor. Individuals with symptoms associated with hay exposure were more often SPT positive to L. destructor than those not having symptoms (P < 0.01). CONCLUSIONS: In a random urban population, 6.3% showed IgE-mediated allergy to L. destructor. These were often polysensitized atopics with a high prevalence of clinical symptoms associated with exposure to hay.

[Airborne immediate allergy in Mid-North Iceland.].

OBJECTIVE: To investigate main causes of airborne immediate allergy in a region of one primary health care center with about 17,000 inhabitants in the northern part of Iceland, both in general and with special reference to diagnoses. MATERIAL AND METHODS: Totally 600 individuals with symptoms indicating airborne immediate allergy were investigated under the periode 1988-1995. Skin prick test (SPT) was used in a standardized way and with standardized solutions. Histamine 10 mg/ml was used as a positive control and positive results were defined as at least half as big as the histamine reaction. RESULTS: 47% of investigated individuals had positive SPT. Grass gave most often positive response and animal dander from cat were in the second place. The allergy symptoms start in more than half of the cases under the age of 16. House dust mites allergy are confirmed in only about 10% of the cases. Mean age of patients who came to the health care center with allergy is 23+/-13 years and 34+/-17 years of those without allergy and the difference is significant in both sexes (p<0.001). When patients with grass pollen allergy are divided into two groups, those with and those without a family history (parents or siblings) of allergy, it is evident that those with a family history get their allergic disease significantly earlier in life than those without a family history (p<0.01). CONCLUSIONS: Immediate airborne allergy is, as is quite well known, mostly a disease of children and young people. By far the most common cause in Mid-North Iceland is grasspollen as in South-West Iceland. Birch pollen is more common in the northern part, probably because of a different vegetation. Age distribution in the whole group without regard to diagnosis is the same as in South-West Iceland where patients with chronic rhinitis were investigated. Storage mite Lepidoglyphus destructor is often positive in those working with hay and it should be included in standard panel for skin prick tests in Northern Iceland.