Sustained effect of SQ-standardized grass allergy immunotherapy tablet on rhinoconjunctivitis quality of life.

BACKGROUND: The prevalence of allergic rhinoconjunctivitis has increased significantly over the past decades with grass pollen being a common trigger. The impact of allergy on patient's quality of life is substantial. AIM: To investigate the sustained effect on quality of life during the grass pollen season 1 year after 3 years of treatment with the SQ-standardized grass allergy immunotherapy tablet (AIT), Graza (Phleum pratense 75,000 SQ-T/2800 BAU; ALK, Denmark). METHODS: The trial was a randomized, parallel-group, double-blind, placebo-controlled trial in adult subjects with a history of moderate-severe grass pollen induced rhinoconjunctivitis inadequately controlled by symptomatic medications. Subjects received 3 years of grass AIT (n = 157) or placebo (n = 126), followed by 1 year of follow-up. Quality of life assessments were based on the standardized rhinoconjunctivitis quality of life questionnaire (RQLQ(S)); completed weekly during the entire grass pollen season. RESULTS: During follow-up, the overall RQLQ(S) score for the entire grass pollen season was significantly improved in the active group (relative difference to placebo: 23%, P = 0.004). The improvement was higher during the peak pollen season (28%, P = 0.001). The treatment effect of grass AIT during the follow-up year and the previous three treatment years was similar. Improvements were found in all seven RQLQ(S) domains. The RQLQ(S) as a function of the weekly average pollen counts showed a clear separation between the treatment groups (P < 0.001). CONCLUSION: In subjects inadequately controlled by symptomatic medications, grass AIT provided sustained and clinically relevant improvements in rhinoconjunctivitis quality of life compared to placebo. The effect increased with increasing grass pollen exposure.

Quality assurance ofallergen-specific immunotherapy during a national outbreak of anaphylaxis: results of a continuous sentinel event surveillance system.

BACKGROUND AND OBJECTIVE: Subcutaneous allergen-specific immunotherapy (SCIT) is an effective treatment for patients with allergic asthma and rhinitis. SCIT may be performed in many different ways and good safety profiles have been published. Other studies, however, have reported high frequencies of severe adverse events (SAEs) but without identifying the causes. After an increase in SCIT-related SAEs in Denmark between 2003 and 2004, strict performance regulations were imposed by the authorities. Because safety data from national databases were not available, we implemented a surveillance system aimed at identifying the causes of SAEs. METHODS: We prospectively registered the number of injections and SAEs during SCIT. A slow up-dosing regimen was used and adherence to international standards was optimized. RESULTS: No SAEs were observed with 28 992 injections. The maximal risk per injection was calculated at < 1.3 per 10 000 injections. DISCUSSION: Our results confirm the good safety profile of SCIT. We applied a sentinel SCIT surveillance system that may offer a means of guaranteeing safety by providing online feedback to all participating clinics when SAEs occur in order to explore their causes by root course analyses performed by all participants. Furthermore, such quality assurance documentation may facilitate wider acceptance of SCIT by health care administrators, clinicians, and patients.

Screening for allergic respiratory disease in the general population with the ADVIA Centaur Allergy Screen Assay.

BACKGROUND: In patients in whom the clinical indication for immunoglobulin E (IgE)-mediated allergic respiratory disease is weak, a single qualitative multiallergen-screening assay for IgE antibody to multiple allergen specificities may support the absence of IgE-mediated allergic respiratory disease. The aim was to investigate the diagnostic efficacy of a new multiallergen-screening assay in relation to skin prick test (SPT) reactivity and objective diagnoses of allergic respiratory disease in a general population setting. METHODS: A total of 709 participants in a population-based study were examined by questionnaire and SPT. Serum was analysed by using a multiallergen-screening assay: the ADVIA Centaur Allergy Screen (AS) assay. The dichotomized result of the AS assay was compared with SPT reactivity, specific IgE positivity, and a clinical diagnosis of allergic rhinitis or allergic asthma defined by the presence of relevant symptoms and positive SPTs. RESULTS: Sensitivity, specificity, and positive (PPV) and negative predictive values (NPV) of the AS against SPT reactivity were 86%, 96%, 94%, and 89%, respectively. A negative AS assay test was able to exclude allergic rhinitis and allergic asthma with a probability of more than 96% and 98% (NPV), respectively. The AS assay was able to identify more than 92% and 92% (sensitivity) of cases of allergic rhinitis and allergic asthma, respectively. CONCLUSIONS: The AS assay proved to be a valid measure of allergic respiratory disease and may be used as a screening tool to rule out allergic respiratory disease, and as an objective measure of allergic respiratory disease in epidemiological studies.

Airborne chemicals cause respiratory symptoms in individuals with contact allergy.

Exposure to fragrance chemicals causes various eye and airway symptoms. Individuals with perfume contact allergy report these symptoms more frequently than individuals with nickel allergy or no contact allergies. However, the associations between contact allergy and respiratory symptoms elicited by airborne chemicals other than perfumes are unclear. The study aimed to investigate the association between eye and airway symptoms elicited by airborne chemicals (other than perfumes) and contact allergy in a population-based sample. A questionnaire on respiratory symptoms was posted, in 2002, to 1189 individuals who participated in 1997/1998 in a Danish population-based study of allergic diseases. Questions about eye and airway symptoms elicited by different airborne chemicals and airborne proteins were included in the questionnaire. Data from the questionnaire were compared with data on patch testing and prick testing. Having at least 1 positive patch test (adjusted odds ratio 1.7, 95% CI 1.2-2.5) was associated with the symptoms, and the odds ratio increased with the number of positive patch tests (P-value for test for trend <0.05). Bronchial hyperreactivity, female sex and psychological vulnerability were independently associated with symptoms, but no association was found between prick test reactivity to proteins and the symptoms elicited by airborne chemicals.

Mucosal symptoms elicited by fragrance products in a population-based sample in relation to atopy and bronchial hyper-reactivity.

BACKGROUND: Exposure to perfume and fragrance products may, in some individuals, cause symptoms from the eyes and airways. The localization, character and risk factors of such symptoms in the general population are unknown. OBJECTIVE: To investigate both the localization and character of symptoms from the eyes and airways elicited by fragrance products, and the associations between such symptoms and skin prick test reactivity (atopy), methacholine bronchial hyper-reactivity (BHR), allergic rhinitis and asthma. METHODS: A questionnaire on mucosal symptoms elicited by fragrance products was posted to 1189 persons who had participated in a Danish population-based study of allergic diseases in 1997/1998. The study included measurement of BHR, atopy, forced expiratory volume in 1 s (FEV1), and serum eosinophilic cationic protein (serum ECP). RESULTS: The response rate was 79.6%. Symptoms from the eyes or airways elicited by fragrance products were reported by 42%. BHR (adjusted odds ratio 2.3, 95% confidence interval 1.5-3.5) was independently associated with symptoms from the eyes and airways elicited by fragrance products. There were no significant associations between these symptoms and atopy, FEV1 or serum ECP. CONCLUSIONS: Mucosal symptoms from the eyes and airways were common in this population. BHR was a significant and independent predictor of these symptoms. The lack of association with atopy suggested that IgE-mediated allergic mechanisms do not play a major role in the development of these symptoms.

A link between skin and airways regarding sensitivity to fragrance products?

BACKGROUND: Exposure to volatile fragrances is commonplace and may be related to various eye and airway symptoms. Skin exposure to fragrances is known to cause perfume contact allergy and eczema, but it is unknown whether eye or airway symptoms elicited by fragrance products are associated with contact allergy or eczema. OBJECTIVES: To investigate if eye and airway symptoms elicited by fragrance products are associated with perfume contact allergy or hand eczema in a population-based sample. METHODS: A questionnaire on eye and airway symptoms elicited by fragrance products was mailed to 1189 individuals who had recently participated in a Danish population-based study of allergic diseases. Results from the questionnaire about localization and character of the symptoms were compared with data on patch testing and 1-year prevalence of hand eczema collected during the health examination. RESULTS: Positive, independent and significant (P < 0.05) associations were found between eye and airway symptoms elicited by fragrance products and perfume contact allergy (adjusted odds ratios 2.0-3.7) and hand eczema (adjusted odds ratios 1.6-2.6). In further analysis, similar and consistent results were found regarding severity of the symptoms. No associations were found between nickel contact allergy and the symptoms. Female sex and psychological vulnerability were independently associated with eye and airway symptoms elicited by fragrance products, but adjustment in multivariate analysis did not change the results regarding perfume contact allergy and hand eczema. CONCLUSIONS: Individuals with perfume contact allergy and/or hand eczema, as opposed to those without, have more frequent and more severe eye or airway symptoms after exposure to volatile fragrance products. Having hand eczema has the greatest impact on reporting eye and airway symptoms elicited by fragrance products.

Pets in the home and the development of pet allergy in adulthood. The Copenhagen Allergy Study.

BACKGROUND: The aim of the study was to investigate the association between exposure to cat and dog in the home and the development (incidence) of IgE sensitization to cat and dog. METHODS: Participants in a population-based study of 15-69-year-olds in 1990 were invited to a follow-up in 1998. Serum IgE antibodies against common inhalant allergens was assessed in 734 subjects (participation rate 69.0%) on two occasions 8 years apart. Information about current or previous keeping of cats and dogs in the home was obtained in a questionnaire at baseline. RESULTS: A cat in the home currently was significantly associated with the development of IgE sentisization to cat (adjusted odds ratio 8.4, 95% confidence interval (CI) 1.7-42.7). Moreover, an atopic predisposition in terms of IgE sensitization to allergens other than cat at baseline was an independent risk factor for the development of IgE sensitization to cat. A dog in the home was not significantly associated with the development of IgE sensitization to dog. CONCLUSIONS: In this adult population, exposure to a cat in the home increased the risk of developing IgE sensitization to cat. More prospective data are needed on this issue.

The relationship of alcohol consumption to total immunoglobulin E and the development of immunoglobulin E sensitization: the Copenhagen Allergy Study.

BACKGROUND: Several studies in patient populations have reported a positive association between alcohol consumption and serum total IgE. Furthermore, we have previously reported a positive association between alcohol consumption and the prevalence of skin prick test (SPT positivity) to inhalant allergens in a population-based cross-sectional study. OBJECTIVE: To investigate the relationship of alcohol consumption to levels of serum total IgE and the development of IgE sensitization to inhalant allergens. METHODS: In 1990, self-reported consumption of alcohol, serum total IgE, SPT positivity and specific IgE positivity to inhalant allergens were assessed in 1112 subjects, aged 15-69 years, participating in a population-based cross-sectional study in Copenhagen, Denmark. In 1998, they were invited to a follow-up and 734 were re-examined (participation rate 69.0%). Adjustment for potential confounders was performed by using multivariable regression analyses. RESULTS: In non-atopic (specific IgE negative) subjects there was a positive association between alcohol consumption and the concentration of total IgE (P = 0.001). During the follow-up period, 45 and 33 subjects developed SPT positivity and specific IgE positivity, respectively. There was no significant association between alcohol consumption and the development of SPT positivity or specific IgE positivity. However, the risk of developing SPT positivity tended to increase with increasing consumption of alcohol (P = 0.055). CONCLUSIONS: This epidemiological study confirms that alcohol consumption has an influence on levels of serum total IgE. A significant association between alcohol consumption and the development of IgE sensitization was not established. However, there seems to be a lack epidemiological data on this issue.

The link between allergic rhinitis and allergic asthma: a prospective population-based study. The Copenhagen Allergy Study.

BACKGROUND: It has been hypothesized that allergic rhinitis and allergic asthma are manifestations of the same disease entity. We aimed to investigate the relationship between allergic rhinitis and allergic asthma. METHODS: Participants in a population-based study of 15-69-year-olds in 1990 were invited to a follow-up in 1998. A total of 734 subjects were examined on two occasions eight years apart. Allergic rhinitis to pollen was defined as a history of nasal symptoms on exposure to pollens and IgE specific to pollen. Allergic asthma to pollen was defined as a history of lower airway symptoms on exposure to pollens and IgE specific to pollen. Similarly, diagnoses of allergic rhinitis and allergic asthma to animals or mite were defined. RESULTS: At follow-up, all subjects with allergic asthma to pollen (n = 52) had in addition allergic rhinitis to pollen. In the longitudinal analysis, there were a total of 28 new (incident) cases of allergic asthma to pollen. They all had allergic rhinitis to pollen at baseline, or had developed allergic rhinitis to pollen at follow-up. Accordingly, allergic rhinitis to animals and mite were ubiquitous in subjects with allergic asthma to animals and mite, respectively. CONCLUSIONS: The results support the hypothesis that allergic rhinitis and allergic asthma are manifestations of the same disease entity.

Incidence of allergic contact sensitization in Danish adults between 1990 and 1998; the Copenhagen Allergy Study, Denmark.

BACKGROUND: Studies of incidence of contact allergy in a general population have not been reported. Data from incidence studies may support and direct strategies for prevention of contact allergy and allergic contact dermatitis. OBJECTIVE: To study the incidence of contact allergy and evaluate risk factors for developing contact allergy in an adult general population sample. PATIENTS AND METHODS: In 1990 a random sample of 567 persons of the 15-69-year-old population living in the western part of Copenhagen County (Denmark) was patch tested in a cross-sectional study. In 1998 a follow-up study was performed. Of 540 invited, 365 (68%) were patch tested again. RESULTS: In the follow-up study, 37 persons (12%) of the 313 patch-test-negative persons in 1990 had developed one or more positive patch tests (incident contact allergy). Twenty cases (6%) of incident nickel allergy and 25 cases (8%) of incident contact allergy to one or more haptens other than nickel were found. The data indicate that female sex, young age and ear piercing (before 1990) were risk factors for developing nickel allergy. Between 1990 and 1998 metal contact dermatitis was reported in seven women with incident nickel allergy. Six of these women had bought the eliciting item in Denmark before 1995, when vigorous control of the Danish nickel legislation was introduced. CONCLUSIONS: We found a considerable number of incident cases of contact allergy in the adult population. The results of the study support the actions taken to restrict the use of the allergens most frequently encountered, and to increase the labelling demands to products intended for prolonged contact with the skin or a combined action.

Is the increase in allergic respiratory disease caused by a cohort effect?

BACKGROUND: Changes in lifestyle or environmental factors are responsible for the increasing prevalence of allergic respiratory disease. Establishing the time at which the increase began may provide a clue as to what factors possibly could have contributed to the increase. Many cross-sectional studies have shown that the prevalence of allergic sensitization decreases with increasing age. This could reflect the natural course of allergic sensitization. Alternatively, this could reflect that the increase in sensitization is caused by a cohort effect, i.e. an increase among subjects born during recent decades. OBJECTIVE: The aim was to investigate age-specific changes in the prevalence of allergic sensitization in a cohort of adults. METHODS: A total of 599 subjects aged 15 to 69 years participated in a cross-sectional general population study in 1990. In 1998 they were invited to a follow-up, and 64.4% (386/599) were reexamined. Serum samples obtained from the participants in 1990 and 1998 were analysed for specific IgE to six common inhalant allergens with the same assay. RESULTS: The prevalence of allergic sensitization (specific IgE to at least one allergen) increased among subjects who were less than c. 30 years at baseline (1990), i.e. subjects born during the 1960s or later, while the prevalence was unchanged among subjects who were more than c. 30 years at baseline. CONCLUSIONS: The results support the notion that the increasing prevalence of allergic respiratory disease is caused by a cohort effect. Thus, changes in lifestyle or environmental factors that occurred around or after 1960 may have contributed to this increase.

Factors related to allergic sensitization to aeroallergens in a cross-sectional study in adults: The Copenhagen Allergy Study.

BACKGROUND: The factors underlying recent increases in the prevalence of respiratory allergy are largely unknown. OBJECTIVE: To assess the association between allergic sensitization and several lifestyle/environmental factors. METHODS: A cross-sectional population-based study of 15-69-year-olds in Copenhagen was carried out in 1990. The participation rate was 77.5% (1112/1435). Different lifestyle/environmental factors (explanatory variables) were defined based on questionnaire data. Dependent (outcome) variables were skin prick test (SPT) positivity or specific IgE positivity to common aeroallergens. Explanatory variables associated with outcome in univariate analysis (P < 0.25) were selected for multivariate analysis. Subsequently, a final model for each dependent variable was obtained by stepwise regression analysis (cut-off for entry/removal of variables: P < 0.1). RESULTS: Male sex, young age, low number of siblings, a positive family history of hay fever and never smoking, were independently associated with both SPT positivity and specific IgE positivity. Furthermore, SPT positivity was positively associated with alcohol consumption (dose-response relationship only), and negatively associated with previous keeping of a dog in the household. The association between alcohol consumption and SPT positivity was mainly due to the consumption of wine and remained after adjustment for educational level. Specific IgE positivity was furthermore associated with body mass index with no apparent dose-response relationship. CONCLUSION: Being male, young age, a positive family history of hayfever, low number of siblings and never smoking, were independently associated with allergic sensitization. In addition, the results indicated a possible relationship of alcohol consumption, body mass index and previous keeping of a dog in the household to allergic sensitization. There is a need for prospective studies of risk factors for respiratory allergy.

Allergic contact sensitization in an adult Danish population: two cross-sectional surveys eight years apart (the Copenhagen Allergy Study).

In 1990 and 1998 15-41-year-old people were patch-tested in 2 cross-sectional studies of random samples of the population in the western part of Copenhagen County, Denmark. In 1990, 290 subjects and in 1998, 469 subjects were patch-tested. The participation rates were 69% and 51%, respectively. Contact sensitivity to one or more haptens was found in 15.9% and 18.6% in 1990 and 1998, respectively. Nickel sensitivity is still the most common contact sensitivity. The risk of contact sensitivity to the cosmetic-related haptens included in the series (formaldehyde was not included) increased significantly from 2.4% in 1990 to 5.8% in 1998 (odds ratio 2.44, 95% confidence interval 1.04-5.73). The prevalence of contact sensitivity to cosmetic-related allergens has been doubled between 1990 and 1998.

Smoking and the development of allergic sensitization to aeroallergens in adults: a prospective population-based study. The Copenhagen Allergy Study.

BACKGROUND: Several cross-sectional population-based studies have reported a negative association between smoking and allergic sensitization to aeroallergens. In a prospective study, we investigated the association between smoking and the development (incidence) of allergic sensitization as reflected by skin prick test (SPT) positivity and specific IgE positivity. METHODS: Participants in a population-based study of 15 69-year-olds in 1990 were invited to a follow-up in 1998. Thus, SPT positivity and specific IgE positivity to common aeroallergens were assessed in 734 subjects (participation rate: 69.0%) on two occasions 8 years apart. The effect of smoking on the development of allergic sensitization was adjusted for potential confounders such as age, sex, family history of hay fever, educational level, and total IgE. RESULTS: During the follow-up period, 58 and 33 subjects developed SPT positivity and specific IgE positivity, respectively. The risk of developing SPT positivity (adjusted odds ratio: 0.45, 95% CI 0.21-0.98) and specific IgE positivity (adjusted odds ratio: 0.62, 95%, CI 0.26-1.49) was lower among sustained smokers than never-smokers. CONCLUSIONS: In this adult population, sustained smoking was negatively associated with the development of allergic sensitization to aeroallergens during an 8-year follow-up. This negative association, if real, might be due to an immunosuppressive effect of smoking.

Secular trends of allergic asthma in Danish adults. The Copenhagen Allergy Study.

Numerous studies have reported increases in asthma prevalence among children world-wide. Less is known about similar trends in adults. We aimed to investigate whether the prevalence of allergic asthma symptoms had increased in an adult general population. Two cross-sectional surveys using identical methods were carried out in 1989 and 1998. A one-page questionnaire on respiratory symptoms was mailed to random samples of 15-41-year-olds living in Copenhagen. The response rates were 86.6% (3624/4185) and 78.8% (2402/3048) in 1989 and 1998, respectively. The questionnaire was validated with specific immunoglobilin E (IgE) positivity as the reference in a random sample of responders in connection with both surveys. We found a significantly increased prevalence of subjects who reported shortness of breath on exposure to pollens (6.6% 0 s. 10.3%, odds ratio 1.61, 95% CI 1.34-1.95), furry animals (5.4% vs. 7.6%, odds ratio 1.45, 95% CI 1.17-1.79), and house dust (7.8% vs. 10.2%, odds ratio 1.35, 95% CI 1.12-1.61). The validation of these symptoms showed that the positive predictive values were reasonably stable over time, which may support that a true increase in allergic asthma has occurred. In conclusion, the prevalence of allergic asthma symptoms increased significantly in this adult general population over a 9-year period.

Persistence of contact allergy among Danish adults: an 8-year follow-up study.

In 1990, a random sample of 567 persons of the 15-69-year-old population living in the Western part of Copenhagen County, Denmark, was patch tested in a cross-sectional study. In 1998, a follow-up study was performed. Out of 540 invited, 365 (68%) were re-patch tested. In the follow-up study, the persistence of allergic contact sensitivity, defined as 1 or more positive patch tests in both surveys, was 71% (37 out of 52 subjects). Nickel allergy persisted in 79% (19 out of 24 subjects), while 60% (21 out of 35 subjects) had a positive patch test reaction to 1 or more allergens, other than nickel, in both surveys. The lowest persistence was 50% (5 out of 10 subjects) and this was found for patch test reactivity to 1 or more of the cosmetic ingredients included in the patch test series. 8 years after the baseline study had demonstrated allergic contact sensitivity, 71% of the subjects still had at least 1 positive patch test. Nickel allergy persisted in 79%. Allergen avoidance should probably be lifelong to prevent elicitation of contact dermatitis.

The prevalence of skin-test-positive allergic rhinitis in Danish adults: two cross-sectional surveys 8 years apart. The Copenhagen Allergy Study.

BACKGROUND: It is disputed whether increases in self-reported respiratory allergy represent a true increase or merely increased recognition. We aimed to investigate whether the prevalence of skin-prick-test (SPT)-positive allergic rhinitis had increased in an adult general population in Copenhagen, Denmark. METHODS: Two cross-sectional surveys were carried out in 1990 and 1998. A screening questionnaire on respiratory symptoms in random samples of 15-41-year-olds preceded both surveys. Among the responders, random samples were invited to a health examination including SPT. Totals of 312 (participation rate 74.6%) and 482 (participation rate 53.4%) subjects were examined in 1990 and 1998, respectively. Diagnoses of SPT-positive allergic rhinitis were based on a history of nasal symptoms on exposure to allergens and SPT positivity to allergens. RESULTS: The prevalence of a diagnosis of SPT-positive allergic rhinitis increased from 12.9% to 22.5% (adjusted odds ratio 1.94, 95% CI 1.30-2.90), whereas the prevalence of a positive SPT (allergen histamine wheal ratio > or = 0.5) to one or more of 10 allergens increased from 27.7% to 33.9% (adjusted odds ratio 1.47, 95% CI 1.05-2.05). CONCLUSIONS: The prevalence of SPT-positive allergic rhinitis has increased significantly. Our findings indicate that a true increase in respiratory allergy has occurred.

Increasing prevalence of specific IgE to aeroallergens in an adult population: two cross-sectional surveys 8 years apart: the Copenhagen Allergy Study.

BACKGROUND: There is evidence that the prevalence of respiratory allergy has increased in children in many countries. However, this evidence is largely based on questionnaire data, and little is known about similar trends in adults. OBJECTIVE: We investigated whether the prevalence of specific IgE to aeroallergens had increased in an adult general population over an 8-year period. METHODS: Two cross-sectional surveys were carried out in 1990 and 1998. A mailed screening questionnaire on respiratory symptoms sent to random samples of 15- to 41-year-old subjects living in Copenhagen (Denmark) preceded both surveys. Random samples of responders were invited to a health examination, including assessment of specific IgE to 6 common aeroallergens. Totals of 312 (74.6% of the invited subjects) and 482 (53.4% of the invited subjects) subjects were examined in 1990 and 1998, respectively. Analyses of serum samples from both surveys were performed in 1999. RESULTS: The prevalence of specific IgE to at least one allergen increased significantly from 1990 to 1998 (26.5% vs 33.9%; odds ratio adjusted for sex, age, and season of examination, 1.63; 95% confidence interval, 1.15-2.32; P = .006). This increase remained unexplained after adjustment for changes in questionnaire variables on lifestyle and home environment. The clinical significance of this increase was underlined by a corresponding increase in the prevalence of allergic rhinitis symptoms associated with specific IgE positivity. CONCLUSION: We found that the prevalence of specific IgE positivity to aeroallergens increased in an adult Danish general population from 1990 and 1998.

Increasing prevalence of allergic rhinitis symptoms in an adult Danish population.

There is evidence that the prevalence of respiratory allergy is increasing. This is mainly based on studies in children and young adults. The aim of the study was to compare the prevalences of self-reported symptoms of respiratory allergy among Danish adults in two surveys 8 years apart. Identical questionnaires were mailed to two random general population samples in 1989 and 1997. The response rates were 86.1% (n = 3603) and 86.4% (n = 817), respectively. The sampling frame and sampling method were identical in both surveys. The changes in the prevalences of symptoms were expressed by sex- and age-adjusted odds ratios comparing 1997 to 1989. We found a significant increase in the prevalence of seasonal rhinitis symptoms (OR=1.6, 95% CI 1.4-1.9), rhinitis symptoms on exposure to pollen (OR =1.6, 95% CI 1.4-1.9), rhinitis symptoms on exposure to furry animals (odds ratio 1.6, 95% CI 1.3-2.0), rhinitis symptoms on exposure to house dust (OR = 1.3, 95% CI 1.1-1.6), and breathlessness on exposure to pollen (OR = 1.5, 95% CI 1.0-2.0). The observed increases were independent of sex and age. The questionnaire was validated in relation to allergen skin test reactivity in a subgroup of the responders to the 1989 survey. When the estimated associations between symptoms and skin test reactivity were considered, the results suggested an increase in allergy to pollen and animal dander. In conclusion, we found evidence of increased prevalence of allergic rhinitis symptoms associated with skin test reactivity.