Increasing prevalence of allergic rhinitis symptoms in an adult Danish population

A systematic review of the effects of temperature and precipitation on pollen concentrations and season timing, and implications for human health

Climate and weather directly impact plant phenology, affecting airborne pollen. The objective of this systematic review is to examine the impacts of meteorological variables on airborne pollen concentrations and pollen season timing. Using PRISMA methodology, we reviewed literature that assessed whether there was a relationship between local temperature and precipitation and measured airborne pollen. The search strategy included terms related to pollen, trends or measurements, and season timing. For inclusion, studies must have conducted a correlation analysis of at least 5 years of airborne pollen data to local meteorological data and report quantitative results. Data from peer-reviewed articles were extracted on the correlations between seven pollen indicators (main pollen season start date, end date, peak date, and length, annual pollen integral, average daily pollen concentration, and peak pollen concentration), and two meteorological variables (temperature and precipitation). Ninety-three articles were included in the analysis out of 9,679 articles screened. Overall, warmer temperatures correlated with earlier and longer pollen seasons and higher pollen concentrations. Precipitation had varying effects on pollen concentration and pollen season timing indicators. Increased precipitation may have a short-term effect causing low pollen concentrations potentially due to "wash out" effect. Long-term effects of precipitation varied for trees and weeds and had a positive correlation with grass pollen levels. With increases in temperature due to climate change, pollen seasons for some taxa in some regions may start earlier, last longer, and be more intense, which may be associated with adverse health impacts, as pollen exposure has well-known health effects in sensitized individuals.

MP-AzeFlu provides rapid and effective allergic rhinitis control: results of a non-interventional study in Denmark

BACKGROUND

Allergic rhinitis (AR) control is a priority in the European Union (EU), and Allergic Rhinitis and its Impact on Asthma (ARIA) has endorsed a visual analogue scale (VAS) as the new language of AR control. This study evaluated the effectiveness of MP-AzeFlu (Dymista®, antihistamine [azelastine], and intranasal corticosteroid [fluticasone propionate]) using a VAS in real-life clinical practice in Denmark.

METHODS

The multicenter, prospective, non-interventional study included 170 patients (≥12 years) with ARIA-defined moderate-to-severe AR prescribed MP-AzeFlu. Patients assessed symptom severity using a VAS (0 to 100 mm) on days 0, 1, 3, and 7 and after ∼14 days of MP-AzeFlu use. On day 3, patients assessed their disease as well controlled, partly controlled, or uncontrolled. Proportions of patients achieving VAS score cutoffs (well-controlled, partly controlled) were also calculated.

RESULTS

MP-AzeFlu reduced mean ± standard deviation VAS score from 67.1 ± 19.3 mm at baseline to 28.4 ± 23.7 mm on the last day, a reduction of 38.8 ± 27.3 mm. At day 3, 85.6% of patients considered their symptoms to be partly or well controlled. Effectiveness was consistent across disease severity, phenotype (seasonal, perennial, or combined AR), and patient age. Respectively, 28.2%, 44.2%, 61.6%, and 71.4% of patients achieved ≤38 mm well-controlled VAS score cutoff on days 1, 3, and 7, and the last day.

CONCLUSION

MP-AzeFlu provided effective, rapid, and sustained symptom control in a real-life setting among patients from Denmark. These results align with EU and ARIA objectives and support the effectiveness of MP-AzeFlu for the treatment of AR in real life.

Atopy and related clinical symptoms among Swiss medical students from 2007 to 2015

Background

Atopic allergy is a widespread disease with increasing prevalence in the second half of the twentieth century and is most often associated with clinical symptoms, like rhinoconjunctivitis, asthma or eczema. This study explored the prevalence of atopy and polysensitization in nine cohorts of Swiss medical students during the period of 2007-2015. Furthermore, the self-reported allergic symptoms, such as rhinoconjunctivitis, asthma and eczema, among students with and without atopy were assessed.

Methods

Each cohort was assessed in the third study year. Students underwent an ImmunoCAP rapid test, a qualitative point-of-care test, and completed an anonymous questionnaire on age, gender and clinical symptoms including rhinoconjunctivitis, asthma and eczema. Statistical analyses assessed the overall prevalence of atopy in each group and estimated the average annual increase using a linear mixed model. We examined the frequency of occurrence of polysensitization and differences of reported symptoms among students with and without atopy.

Results

Data of 1513 students (mean age 22.4-23.3 years across cohorts) in nine cohorts (median cohort size 215 interquartile range IQR 193-222) were available for analysis. Test results consistent with atopy were present in 39.9% of students. Average increase of atopy over the 9 years of observation was 2.25% (95% CI 0.18-4.31%; p = 0.037). Main drivers for this increase were the ubiquitously available allergens, house dust mite, timothy grass and birch pollen. Atopy and polysensitization were more pronounced in male students: Polysensitization also increased in the observation period. The clinical symptoms, rhinoconjunctivitis, asthma and eczema were reported by 463 (76.7%) atopic and by 141 (15.5%) non-atopic students.

Conclusions

We observed a slight increase of atopy and polysensitization within 9 years of observation in Swiss medical students. The most frequent sensitization occurred with allergens with the highest chance of exposure. Rhinoconjunctivitis, asthma and eczema are a symptom complex associated with atopy but also found in non-atopic students.Trial registration retrospectively registered by the Cantonal Ethics Committee Zurich on 22.01.2016; Nr: 08-2016.

Pollen Season Trends (1973-2013) in Stockholm Area, Sweden

In the present study, the phenological and quantitative changes in the pollen seasons between 1973 and 2013 in the Stockholm region of Sweden were studied for nine types of pollen (hazel, alder, elm, birch, oak, grass, mugwort, willow and pine). Linear regression models were used to estimate the long term trends in duration, start- and end-dates, peak-values and the yearly accumulated pollen sums of the pollen seasons. The pollen seasons of several arboreal plant species (e.g. birch, oak and pine) were found to start significantly earlier today compared to 41 years earlier, and have an earlier peak-date, while the season of other species seemed largely unaffected. However, the long term trends in the end-dates of pollen seasons differed between arboreal and herbaceous species. For herbaceous species (grass and mugwort), a significant change towards later end-dates was observed and the duration of season was found to have increased. A significant trend towards an earlier end-date was found in the majority of the arboreal plant species (i.e. elm, oak, pine and birch), but the length of the season seemed unaffected. A trend towards an increase in yearly concentrations of pollen was observed for several species; however the reasons for this phenomenon cannot be explained unambiguously by the present study design. The trend of increasing yearly mean air temperatures in the Stockholm area may be the reason to changed phenological patterns of pollen seasons.

Fungi in a changing world: growth rates will be elevated, but spore production may decrease in future climates

Very little is known about the impact of climate change on fungi and especially on spore production. Fungal spores can be allergenic, thus being important for human health. The aim of this study was to investigate how climate change influences the responsive ability of fungi by simulating differing environmental regimes. Fungal species with high spore allergenic potential and atmospheric abundance were grown and experimentally examined under a variety of temperatures and different nutrient availability. Each represented the average decadal air temperature of the 1980s, 1990s and 2000s in the UK, along with an Intergovernmental Panel on Climate Change (IPCC) climate change scenario for 2100. All tests were run on six fungal species: Alternaria alternata, Aspergillus niger, Botrytis cinerea, Cladosporium cladosporioides, Cladosporium oxysporum and Epicoccum purpurascens. Mycelium growth rate and spore production were examined on each single species and competitive capacity among species combinations in pairs. All fungal species grew faster at higher temperatures, and this was more pronounced for the temperature projection in 2100. Most species grew faster when there was lower nutrient availability. Exceptions were the species with the highest growth rate (E. purpurascens) and with the highest competition capacity (A. alternata). Most species (except for E. purpurascens) produced more spores in the richer nutrient medium but fewer as temperature increased. C. cladosporioides was an exception, exponentially increasing its spore production in the temperature of the 2100 scenario. Regarding competitive capacity, no species displayed any significant alterations within the environmental range checked. It is suggested that in future climates, fungi will display dramatic growth responses, with faster mycelium growth and lower spore production, with questions risen on relevant allergen potential.

Total IgE plasma levels vary according to gender and age in Brazilian patients with allergic rhinitis

OBJECTIVE

Allergic rhinitis is a disease that affects the upper airways and causes inflammation of the nasal mucosa and it is mediated by IgE antibodies produced after sensitization to environmental allergens. Previous reports have indicated that this disease affects males more often than females. The objective of this study was to verify whether total IgE plasma levels vary between genders in patients suffering from allergic rhinitis.

METHODS

A total of 171 adult patients suffering from allergic rhinitis (55 males and 116 females) were enrolled. Total IgE plasma levels were determined using commercial kits, with 140 IU/mL considered as a reference value. The mean total IgE plasma levels were compared according to gender and age.

RESULTS

The mean age of the overall patient group with allergic rhinitis was 38.4 ± 19.0 years and a significant difference in age was observed between genders (males: 32.2 ± 17.8 years; females: 41.4 ± 18.9 years; p=0.0027). Additionally, the mean total IgE plasma levels were higher in males (413.0 ± 143.0 IU/mL) than in females (147.9 ± 98.0 IU/mL) (p<0.0001). These differences persisted even when males and females were stratified by age (up to or older than 20 years of age).

CONCLUSIONS

In conclusion, total IgE plasma levels are higher in young adult males than in females suffering from allergic rhinitis. Evaluating total IgE plasma levels can be useful to identify patients at risk of allergic rhinitis in areas with low industrial pollution.

[Local (exclusive) IgE production in the nasal mucosa. Evidence for local allergic rhinitis]

BACKGROUND

IgE production at the site of the nasal mucosa without systemic allergic sensitization in skin tests or in serum represents so-called "local allergic rhinitis (LAR)" as a subgroup of patients with symptoms of allergic rhinitis (AR). Formerly, in case of negative allergological test results, seasonal (intermittent) or perennial (persistent) allergic symptoms have been diagnosed as "non-allergic rhinitis" (NAR). However, there is evidence for specific Th2 cytokine, tryptase, and ECP (eosinophil catonic protein) production in the nasal secretion after allergen exposure in these patients without systemic sensitization.

DIAGNOSIS

Taking this into account, we recommend performing an allergen-specific nasal challenge and measuring the (local) nasal IgE-levels in addition to standard allergy tests in clinical routine in this subgroup of patients. These tests should be perfomed while or shortly after allergen exposure. In addition, an update of the allergy testing should be performed after a time interval since it has been demonstrated that patients formerly diagnosed with NAR may develop LAR or AR, or patients with LAR may develop AR in the future.

TREATMENT

The pharmacological therapeutic options in LAR are in line with the treatment of AR. If and to what extent this subgroup of AR patients benefit from allergen-specific immunotherapy (SIT) is currently being evaluated in clinical trials.

Allergic Rhinitis and Secondhand Tobacco Smoke: A Population-based Study

Background

Allergic rhinitis (AR) is a common disease that affects approximately one-fifth of the U.S. population. Few studies have evaluated the association between secondhand tobacco smoke (SHS) exposure and the impacts on symptom severity in AR. In this study, we evaluated the association of SHS and AR in a community-based study of adult nonsmokers.

Methods

In Washington County, Maryland, 83 subjects with AR (physician diagnosed or reported skin test positive), and 117 nonallergic subjects from the same community were recruited and interviewed. A validated questionnaire was used to assess past and present SHS exposure as well as disease-specific quality of life.

Results

SHS was reported in 34/83 allergic subjects. Compared with AR subjects with no SHS exposure, subjects with AR and SHS were more likely to report a family history of chronic sinusitis (p = 0.04) and use nasal decongestants (p = 0.012). There was also a borderline association with reporting more severe nasal obstruction (p = 0.14) and nasal drainage (p = 0.08). Compared with nonallergic subjects, allergic subjects were more likely to report longer SHS exposure currently (adjusted mean difference = 1.6 hours/week; p = 0.01) and 20 years ago (adjusted mean difference = 2.9 hours/week; p = 0.03).

Conclusion

Past and current SHS may be a risk factor for AR. Allergic subjects with SHS exposure were more likely to use nasal decongestants and to report more severe nasal symptoms such as nasal obstruction and nasal drainage than nonexposed allergic subjects.

Increased prevalence of symptoms of rhinitis but not of asthma between 1990 and 2008 in Swedish adults: comparisons of the ECRHS and GA²LEN surveys

Background

The increase in asthma prevalence until 1990 has been well described. Thereafter, time trends are poorly known, due to the low number of high quality studies. The preferred method for studying time trends in prevalence is repeated surveys of similar populations. This study aimed to compare the prevalence of asthma symptoms and their major determinants, rhinitis and smoking, in Swedish young adults in 1990 and 2008.

Methods

In 1990 the European Community Respiratory Health Survey (ECRHS) studied respiratory symptoms, asthma, rhinitis and smoking in a population-based sample (86% participation) in Sweden. In 2008 the same symptom questions were included in the Global Allergy and Asthma European Network (GA²LEN) survey (60% participation). Smoking questions were however differently worded. The regions (Gothenburg, Uppsala, Umeå) and age interval (20–44 years) surveyed both in 1990 (n = 8,982) and 2008 (n = 9,156) were analysed.

Results

The prevalence of any wheeze last 12 months decreased from 20% to 16% (p<0.001), and the prevalence of “asthma-related symptoms” was unchanged at 7%. However, either having asthma attacks or using asthma medications increased from 6% to 8% (p<0.001), and their major risk factor, rhinitis, increased from 22% to 31%. Past and present smoking decreased.

Conclusion

From 1990 to 2008 the prevalence of obstructive airway symptoms common in asthma did not increase in Swedish young adults. This supports the few available international findings suggesting the previous upward trend in asthma has recently reached a plateau. The fact that wheeze did not increase despite the significant increment in rhinitis, may at least in part be due to the decrease in smoking.

Epidemiology of allergic rhinitis caused by grass pollen or house-dust mites in Spain

BACKGROUND

Although the prevalence of allergic rhinitis (AR) is increasing, relatively little is known about patient characteristics in Spain. The aim of this study was to investigate the clinical profile and therapeutic strategies in patients attending Spanish specialists for AR caused by grass pollen or house-dust mites (HDMs).

METHODS

This was a multicenter cross-sectional epidemiological study of consecutive patients aged ≥5 years with confirmed diagnosis of AR caused by grass pollen or HDMs attending allergy specialists throughout Spain. Demographic and clinical data and information on treatment were collected.

RESULTS

Data from 1043 patients were analyzed (524 with grass pollen allergy and 519 with HDM allergy; mean age, 27.1 years). Three-quarters had persistent AR as per the Allergic Rhinitis and Its Impact on Asthma (ARIA) definition, with disease duration of >2 years in 94.3% of those with pollen allergy and 85.5% of those with HDM allergy. Approximately 38% had concurrent asthma. Over one-half of the patients were considered to have gotten worse since the first onset of symptoms. In total, 51.5% did not achieve good disease control with pharmacotherapy and 47.7% were treated with immunotherapy (52.2% of HDM allergic patients and 43.2% of grass pollen-allergic patients).

CONCLUSION

The duration of AR in patients attended for the first time by specialists is long and, in general, the disease does not improve over time and is often not well controlled with pharmacologic interventions. Less than one-half of patients receive allergen-specific immunotherapy that is more often prescribed in HDM allergy.

Serum eosinophil granule proteins predict asthma risk in allergic rhinitis

BACKGROUND

Allergic rhinitis is a common disease, in which some patients will deteriorate or develop asthma. It is important to characterize these patients, thereby offering the possibility for prevention. This study evaluated eosinophil parameters as potential indicators of deteriorating allergic airway disease.

METHODS

The subjects of the study included all patients who suffered seasonal allergic rhinitis and had participated in a study 6 years earlier, in which blood eosinophils, serum eosinophil cationic protein (ECP) serum eosinophil peroxidase (EPO), nasal lavage ECP and nasal lavage EPO levels were measured. Patients in the present study were interviewed on occurrence of rhinitis symptoms during the last season, rhinitis outside season, asthma-like symptoms and asthma diagnosis, and were skin-prick tested for common aeroallergens. Eosinophil parameters from the study 6 years earlier were then tested for the ability to predict occurrence of new allergies, worsening of rhinitis and occurrence of asthma.

RESULTS

Forty-four patients participated in the study. In four patients seasonal rhinitis symptoms had deteriorated, 10 had experienced perennial rhinitis symptoms, 14 reported asthma-like symptoms and seven had been diagnosed with asthma. Thirteen had developed additional sensitization. Patients developing asthma-like symptoms compared with patients with no such symptoms had significantly higher serum ECP (16.7 microg/l vs 8.2 microg/l; P < or = 0.01) and serum EPO (17.9 microg/l vs 8.8 microg/l; P < or = 0.05). Results were similar, considering patients diagnosed with asthma. Blood eosinophils and nasal lavage parameters were not related to development of asthma and asthma-like symptoms. No eosinophil parameter was related to deterioration of rhinitis or additional sensitization.

CONCLUSION

Serum ECP and EPO in patients with seasonal rhinitis demonstrated a high predictive ability for later development of asthma.

The association between alcohol consumption and contact sensitization in Danish adults: the Glostrup Allergy Study

BACKGROUND

Population-based epidemiological studies have indicated that alcohol consumption is associated with IgE-mediated immune diseases (i.e. allergic rhinitis, asthma and urticaria). These studies have been strongly supported by several immunological studies. Furthermore, an inhibitory effect of alcohol consumption on the development of delayed-type hypersensitivity has been shown in healthy controls. However, a possible association between contact sensitization and alcohol consumption in a general population has never been reported.

OBJECTIVES

To investigate whether alcohol consumption is associated with contact sensitization in a general population.

METHODS

In 1990, self-reported consumption of alcohol and patch testing results were assessed in 1112 subjects, aged 15-69 years, participating in a population-based cross-sectional study in Glostrup, 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 logistic regression analyses.

RESULTS

Women who reported no consumption of alcoholic drinks per week were more likely to develop contact sensitization (adjusted odds ratio 2.12, 95% confidence interval 0.98-4.61) during a 8-year follow-up period. A positive trend among women was detected (P=0.045).

CONCLUSIONS

These data support the hypothesis that alcohol consumption leads to IgE-mediated immune responses rather than delayed-type hypersensitivity reactions. It is probable that alcohol consumption prevents the development of contact sensitization. Further epidemiological studies are warranted.

Differences between allergic and nonallergic rhinitis in a large sample of adolescents and adults

BACKGROUND

The aim of this study was to describe differences between allergic rhinitis (AR) and nonallergic rhinitis (NAR) in a large community-based sample of Danish adolescents and adults.

METHODS

A total of 1,186 subjects, 14-44 years of age, who in a screening questionnaire had reported a history of airway symptoms suggestive of asthma and/or allergy, or who were taking any medication for these conditions were clinically examined. All participants were interviewed about respiratory symptoms and furthermore skin test reactivity, lung function and airway responsiveness were measured using standard techniques.

RESULTS

A total of 77% of the subjects with rhinitis had AR, whereas 23% had NAR. Subjects with NAR were more likely to be females, OR = 2.05 (1.31-3.20), P = 0.002, to have persistent symptoms within the last 4 weeks, OR = 1.88 (1.23-2.89), P = 0.003, and to have recurring headaches, OR = 1.94, (1.12-3.37), P = 0.019. On the other hand, subjects with NAR were less likely to have airway hyperresponsiveness, OR = 0.40, (0.24-0.66), P < 0.001, food allergy, OR = 0.40, (0.19-0.36), P = 0.009 and to have been treated with antihistamines in the last 4 weeks, OR = 0.22, (0.13-0.38), P < 0.001 compared with subjects with AR. Subjects with AR were symptomatically worse within their season in terms of sneezing (P < 0.001) and itchy eyes (P < 0.001), compared to subjects with NAR, whereas nasal congestion and rhinorrhea were equally frequent in the two groups (P = 0.901 and P = 0.278, respectively).

CONCLUSIONS

The proportion of subjects with NAR in an adolescent and adult population with rhinitis is around one-fourth. Women have NAR twice as often as men. In general, subjects with NAR have more persistent but equally severe symptoms compared to subjects with AR. However, subjects with AR have more sneezing and itchy eyes within their particular season of allergy compared to subjects with NAR.

[Occupational rhinitis]

INTRODUCTION

Rhinitis is one of the most common occupational diseases. It is often neglected by those affected because it causes little disability. It is poorly understood by doctors who have insufficient experience of occupational diseases and their causes. However it is often the first manifestation of a respiratory disorder that may cause physical complications and socio-economic disability.

BACKGROUND

Numerous diverse agents are potential causes of rhinitis. The diagnosis of occupational rhinitis should be considered when sneezing, rhinorrhoea or nasal obstruction are associated with work. The causal agent can be identified by ta-king a careful history. When the mechanism of the disease is immunologic the suspected antigen can be confirmed by skin testing, specific IgE or nasal provocation. The respiratory disorder of which rhinitis is the first manifestation may progress to asthma if the exposure continues. The prevention of occupational rhinitis depends on the reduction of exposure to allergens and/or irritants. When it has developed removal of the causative agent is essential to prevent progression to asthma.

Allergic sensitization and microbial load--a comparison between Finland and Russian Karelia

Epidemiological data have indicated that some infections are associated with a low risk of allergic diseases, thus supporting the idea (hygiene hypothesis) that the microbial load is an important environmental factor conferring protection against the development of allergies. We set out to test the hygiene hypothesis in a unique epidemiological setting in two socio-economically and culturally markedly different, although genetically related, populations living in geographically adjacent areas. The study cohorts included 266 schoolchildren from the Karelian Republic in Russia and 266 schoolchildren from Finland. The levels of total IgE and allergen-specific IgE for birch, cat and egg albumen were measured. Microbial antibodies were analysed against enteroviruses (coxsackievirus B4), hepatitis A virus, Helicobacter pylori and Toxoplasma gondii. Although total IgE level was higher in Russian Karelian children compared to their Finnish peers, the prevalence of allergen-specific IgE was lower among Russian Karelian children. The prevalence of microbial antibodies was, in turn, significantly more frequent in the Karelian children, reflecting the conspicuous difference in socio-economic background factors. Microbial infections were associated with lower risk of allergic sensitization in Russian Karelian children, enterovirus showing the strongest protective effect in a multivariate model. The present findings support the idea that exposure to certain infections, particularly in childhood, may protect from the development of atopy. Enterovirus infections represent a new candidate to the list of markers of such a protective environment. However, possible causal relationship needs to be confirmed in further studies.

Levocetirizine: a review of its use in the management of allergic rhinitis and skin allergies

Levocetirizine (Xyzal) is a selective, potent, oral histamine H(1) receptor antagonist of the latest generation that is licensed for the symptomatic treatment of allergic rhinitis (including persistent allergic rhinitis [PER]) and chronic idiopathic urticaria (CIU). Large, well designed trials indicate that levocetirizine is effective and generally well tolerated in the treatment of allergic rhinitis and CIU. Its pharmacological profile offers many positive aspects: a rapid onset and long duration of antihistaminic effect; rapid absorption and high bioavailability; a low potential for drug interactions; a low volume of distribution; and a lack of effect on cognition, psychomotor function and the cardiovascular system. Allergen challenge chamber studies suggest that levocetirizine has better efficacy than desloratadine, loratadine or fexofenadine. Well controlled, long-term studies with other later-generation H(1) receptor antagonists are required to fully define its clinical profile relative to other agents in this class. Overall, levocetirizine is a valuable addition to the oral H(1) receptor antagonists available for the treatment of allergic rhinitis and as first-line therapy in patients with CIU.

Frequency of allergic diseases following measles

OBJECTIVE

Viral and bacterial infections in childhood decrease the likelihood of allergic diseases in later life. The frequency of allergic diseases in patients with a history of measles has been reported to be low but some studies still suggest that measles can increase the frequency of allergic diseases. The aim of this study was to investigate the frequency of allergic diseases following measles in childhood.

METHODS

Fifty-two children hospitalized in our clinic with measles were compared with 51 children without measles. Allergic diseases were investigated in both groups by using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. In all children, allergy skin tests were performed with the four most common allergens.

RESULTS

Sensitivity to Dermatophagoides pteronyssinus was less frequent in children with measles than in those without (p < 0.05). A history of nebulized salbutamol use in the emergency room in the previous 12 months was also less frequent in the measles group (p < 0.05). Inhaled corticosteroid use was more common in the group without measles (p < 0.05).

CONCLUSION

The results of this study indicate that findings of allergic disease are less frequent in children with a history of measles. These children were less sensitive to D. pteronyssinus.

Physician-diagnosed asthma and allergic rhinitis in Manitoba: 1985-1998

BACKGROUND

A worldwide increase has been noted in the prevalence of asthma, but the data for other allergic disorders are less consistent.

OBJECTIVE

To study 14-year trends in utilization of physician resources for asthma and compare them to trends for allergic rhinitis.

METHODS

We studied visits to physicians by Manitoba residents for asthma (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 493) and allergic rhinitis (ICD-9 code 477) between 1985 and 1998. Prevalence and incidence of physician resources utilization were calculated annually for the total population and by age groups. Aggregate statistics and frequency of physician resources utilization were also analyzed.

RESULTS

The prevalence and incidence of physician resources utilization for asthma increased more than for allergic rhinitis; differences were most striking in the youngest age groups. In adults, the differences were smaller and changed little with time. Most of the increase in asthma care occurred in children and in people without allergic rhinitis. Overall, 17% of Manitobans were diagnosed as having asthma, and the average asthmatic patient made 6 visits. Approximately 14% had an allergic rhinitis diagnosis, each person being seen twice on average. Coexistence of asthma and allergic rhinitis led to increased physician resources utilization for each of the conditions.

CONCLUSIONS

Trends in utilization of physician resources for allergic rhinitis differed strikingly from trends for asthma, particularly in the youngest age group. Asthma and allergic rhinitis affected comparable proportions of the population, but a diagnosis of asthma resulted in much higher utilization of physician resources. The relationship of physician-diagnosed asthma and atopy, as indicated by the diagnosis of allergic rhinitis, appears to have weakened with time in children but not in adults.

Hope for the hygiene hypothesis: when the dirt hits the fan

The hygiene hypothesis was developed in response to data suggesting that the increase in allergic diseases as well as asthma was secondary to a reduced exposure to infectious stimuli. Indeed, the epidemiologic changes, resulting in an increase in atopic disease, have been impressive and intriguing. Furthermore, although there clearly is a genetic component to atopic diseases, genetics cannot account for a marked increase in the incidence and prevalence of allergic manifestations within a few generations. Thus, environmental factors have been suggested as responsible for the changing prevalence. There are two--not mutually exclusive--possibilities, namely, that substances that promote atopy have been added to the environment or that factors that provided protection from allergic disease were lost from the environment. Both outdoor and indoor pollution, along with a long list of other environmental factors, have been proposed. It is of interest that in many developed countries, certain types of pollution have decreased, whereas the prevalence of atopic disease has increased. In this review, we have explored a detailed analysis of a large number of studies that have focused on this issue and suggest that, although the hygiene hypothesis has merit, the stimuli responsible for the new epidemiology remain enigmatic.

Out-of-season recollection of drug use for seasonal IgE-mediated rhinitis: useful but an overestimation

BACKGROUND

The history of seasonal, IgE-mediated (allergic) rhinitis is often obtained postseasonally as a retrospective assessment. It is not known whether recollected drug use is representative for the in-seasonal medication history.

OBJECTIVES

To investigate the agreement between in-seasonal and out-seasonal reports on drugs and drug doses, and to investigate whether retrospective assessment was sufficiently sensitive to detect the effect of intervention.

MATERIAL AND METHODS

Thirty-five patients allergic to birch pollen were allocated to allergen-specific immunotherapy (SIT) or placebo in a double-blind study. Drug use was recorded daily during the season 2000 and out-seasonally 6 months after the seasons 1999 and 2000. The mean daily drug use was transformed into a 4-point categorical scale for simplicity and was calculated for the out-seasonal rating and for 6 in-seasonal periods of different durations. In-seasonal and postseasonal ratings were compared with the Cohen weighted kappa (kappa w).

RESULTS

We observed a high level of agreement between in-seasonal and retrospective reports of drugs used (kappa w > 0.60) and drug doses (kappa w > 0.50). The highest agreement was observed for the in-seasonal day, week, or 2 weeks with the highest drug intake. Out-seasonal ratings significantly overestimated the daily oral and nasal antihistamine use compared with in-seasonal periods >2 weeks. Despite being comparable pretreatment, only the SIT group had a significant decrease in recollected total drug use during SIT.

CONCLUSION

Out-seasonal recollection of hay fever drugs represented a period of a maximum 14 days. It appeared sufficiently sensitive to detect the effect of intervention.

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.

Asthma and other allergic conditions in Colombia: a study in 6 cities

BACKGROUND

No detailed information is available on the burden and impact of allergic diseases simultaneously for adults and children in Colombia and most Latin American countries.

OBJECTIVES

To investigate the prevalence of asthma, allergic rhinitis, and atopic dermatitis symptoms in 6 cities in Colombia; to measure patient expenses and school days and workdays lost; to describe disease severity; and to determine levels of total and specific IgE in asthmatic subjects.

METHODS

A multistage stratified random sample selection of schools with subjects aged 5 to 18 years in each city was used. Guardian subjects selected were contacted, and home visits were arranged. Subjects aged 1 to 4 years and older than 19 years were also selected randomly by systematic sampling based on the addresses of the subjects aged 5 to 18 years. Subjects with asthma symptoms were invited to provide a blood sample.

RESULTS

Information was obtained from 6,507 subjects. The prevalence of asthma, rhinitis, and atopic dermatitis symptoms in the past 12 months was 10.4% (95% confidence interval [CI], 9.7%-11.1%), 22.6% (95% CI, 21.6%-23.6%), and 3.9% (95% CI, 3.4%-4.4%), respectively. Thirty-eight percent of asthmatic subjects had visited the emergency department or have been hospitalized, and 50% reported lost school days and workdays. Seventy-six percent of sampled asthmatic patients were considered to be atopic.

CONCLUSIONS

The burden of disease and societal consequences of allergic entities in urban settings in countries such as Colombia are of concern but are largely ignored, perhaps because of the misconception that these diseases are of public health importance only in industrialized nations.

Age at bacille Calmette-Guérin vaccination and risk of allergy and asthma

BACKGROUND

It has been proposed that early age at bacille Calmette-Guérin (BCG) vaccination protects against the development of allergy.

OBJECTIVE

To study whether early age at BCG vaccination was associated with a decreased risk of atopy, allergic rhinitis, and asthma compared to BCG vaccination at later ages in childhood.

METHODS

The occurrence of atopy, allergic rhinitis, and asthma was studied in nearly 2000 women participating in the Danish National Birth Cohort study. Detailed information on age at BCG vaccination (age 0-15 years) was available from school health records. Atopic status was assessed serologically by a specific response to 11 common inhalant allergens using serum samples obtained from the women during the period 1997-2001. Information on allergic rhinitis and asthma was available from telephone interviews.

RESULTS

Approximately 85% of the women had been BCG-vaccinated. Age at BCG vaccination was not associated with risk of atopy, allergic rhinitis, or asthma. The odds ratio of atopy, allergic rhinitis, and asthma associated with being vaccinated during the first year of life was 1.05 (95% CI 0.71-1.56), 1.42 (95% CI 0.85-2.36), and 1.71 (95% CI 0.91-3.20), respectively, compared with being vaccinated at the age of 7 years. Adjustment for birth cohort, sibship size, age of the woman's mother at birth, and social class in childhood did not affect the results.

CONCLUSION

Our findings suggest that age at BCG vaccination in childhood does not influence the development of allergy or asthma.

Sensitization profiles of Malaysian and Singaporean subjects to allergens from Dermatophagoides pteronyssinus and Blomia tropicalis

BACKGROUND

The house dust mites Dermatophagoides pteronyssinus (Der p) and Blomia tropicalis (Blo t) are the most common house dust mite species in Southeast Asia. To date, there have only been a few studies on the sensitization profile of the general populations in Southeast Asia to house dust mites. The aim of this study was to determine the profiles of Der p and Blo t sensitization among Singaporean and Malaysian subjects.

METHODS

Enzyme-linked immunosorbent assay was used to detect specific IgE to Der p and Blo t mite crude extracts as well as purified Der p 1, Der p 2 and Blo t 5 allergens. Sera used were from 229 Singaporean subjects (124 with rhinitis, 105 without rhinitis) and 143 Malaysian subjects (94 adults and 49 children with asthma).

RESULTS

The sensitization profile of rhinitis subjects to the dust mite allergens used in this study was as follows: Blo t extract positive: 91/124 (73%); Blo t 5 positive: 62/124 (50%); Der p extract positive: 61/124 (49%); Der p 1 positive: 53/124 (43%); Der p 2 positive: 45/124 (36%). The nonrhinitis subjects' sensitization profile was as follows: Blo t extract positive: 60/105 (57%); Blo t 5 positive: 24/105 (23%); Der p extract positive: 38/105 (36%); Der p 1 positive: 14/105 (13%); Der p 2 positive: 17/105 (16%). The study of Malaysian asthmatic adults showed that 39% of them were sensitized to Der p 1, 32% to Der p 2 and 37% to Blo t 5. Among the asthmatic children, sensitization to Blo t 5, Der p 1 and Der p 2 was 90, 57 and 39%, respectively.

CONCLUSION

This study clearly revealed that dual sensitization to B. tropicalis and D. pteronyssinus is common in the general populations of Singapore and Malaysia. Sensitization to Blo t 5 is more prevalent than to Der p 1 and Der p 2.

Comparative prevalence of sensitization to common animal, plant and mould allergens in subjects with asthma, or atopic dermatitis and/or allergic rhinitis living in a tropical environment

BACKGROUND AND OBJECTIVES

Current information suggests that the expression of allergic diseases is determined by the exposure and nature of the allergen. The objectives of the present study were to determine if the nature of allergenic exposition to animal, plant or fungal allergens influenced the clinical manifestations of atopic dermatitis (AD), allergic rhinitis (AR) or asthma (AS) in patients living in a tropical environment. The prevalence and degree of sensitization to these allergens were analysed by age and gender.

SUBJECTS AND METHODS

A total of 1496 atopic cases, grouped according to the primary diagnosis of AD or AR or AS, were skin tested using a standardized allergen panel. Participants were categorized by age groups. The atopic index (AI) and mean weal diameter (MWD) as well as the prevalence of positive skin tests were determined for each of the patient groups and compared by age groups.

RESULTS

The prevalence of atopy as well as the AI and the MWD peaked at 6-15 years of age and declined thereafter. In all the patients tested, the prevalence of sensitization was, in decreasing order; dust mites 94.3%, cockroach 41.5%, pets 31.5%, plant allergens 31.1% and fungal 19.4%. Eight hundred and ninety-three atopic patients were exclusively sensitized only to animal allergens. Of these, 38.4% had AD, 31.3% had AR and 30.5% with AS.

CONCLUSION

These data demonstrate that for patients with AD, AR and AS living in a tropical environment, the prevalence of positive skin reactions to animal allergens is highest followed by plant and fungal allergens. We did not observe any association between the type of allergen and clinical manifestations. The index of atopy was similar for both sexes. The prevalence and degree of sensitization were shown to peak in young adults independent of the allergen in AD and AR patients.

Allergic rhinitis and polymorphisms of the interleukin 1 gene complex

BACKGROUND

Allergic rhinitis is a chronic inflammatory disease with a genetic background. Inflammatory reactions are regulated by cytokines. Cytokine genes are polymorphic and have been implicated as candidate genes in allergy.

OBJECTIVES

To study the significance of the interleukin 1 (IL-1) gene complex in allergic rhinitis.

METHODS

Population-based, cross-sectional study. We studied the polymorphisms of 3 IL-1 gene complex genes, IL1A (+4845G>T), IL1B (-511 degrees C>T), and IL1RN (variable number of tandem repeats; IVS2, 86 bp, duplicates 2 to 5), in patients with allergic rhinitis. The study group consisted of 405 nonasthmatic individuals of whom 56 had allergic rhinitis.

RESULTS

The genotype distribution differed significantly in all cytokine genes studied between subjects with and without allergic rhinitis. The difference was mainly due to an increased number of IL1A allele G homozygotes (67.9% vs 43.2%; odds ratio [OR], 2.8; 95% confidence interval [CI], 1.5-5.1), IL1B heterozygotes (72.2% vs 47.4%; OR, 2.8; 95% CI, 1.5-5.3), and IL1RN allele 2 homozygotes (18.5% vs 7.5%; OR, 2.8; 95% CI, 1.3-6.2) in allergic rhinitis. Haplotype analysis revealed a significant difference in the distribution of IL-1 gene complex haplotypes between subjects with and without allergic rhinitis (P = 0.005, 10 df).

CONCLUSIONS

The IL-1 gene complex polymorphism is strongly associated with allergic rhinitis in nonasthmatic individuals.

Influence of sensitization to inhalative allergens on adenotonsillar disease

OBJECTIVE: We sought to determine the influence of IgE-mediated sensitization on adenotonsillar disease in children. We compared follow-up after tonsillectomy/adenoidectomy of atopic and nonatopic children.

STUDY DESIGN AND SETTING: A prospective study of 293 children consecutively undergoing tonsillectomy/adenoidectomy was conducted at a university hospital center. Preoperative and postoperative (1-year follow-up) allergy-related symptom scores were obtained by parents. Intraoperative total serum IgE, the screening test sx1 (Pharmacia), and, if positive, serum specific IgE to inhalative allergens were carried out.

RESULTS: Sixty-seven children (22.9%) showed positive RAST results to inhalative allergens (class 1 to 6). In both sensitized and nonsensitized groups, the general health was improved in more than 89% at 1 year postoperatively. No significant difference of postoperative nasal symptoms between the atopic and nonatopic groups was found.

CONCLUSION: Both atopic and nonatopic children with adenotonsillar disease improve health after adenoidectomy or adenotonsillectomy. In our opinion, routine allergy tests before adenotonsillectomy or adenoidectomy are not justified. Only if allergy is suspected due to clinical findings or family history should an allergy test be carried out.

Smallpox vaccination and risk of allergy and asthma

BACKGROUND

It has been proposed that childhood vaccinations may influence the development of allergy. Atopy and allergic diseases have increased after routine smallpox vaccination was stopped in the 1970s.

OBJECTIVE

We examined whether administration of smallpox vaccination during childhood was associated with a decreased risk of atopy, allergic rhinitis, and asthma.

METHODS

The occurrence of atopy, allergic rhinitis, and asthma was studied in nearly 2000 women participating in a national birth cohort study. Detailed information on smallpox vaccination was available from school health records. Atopic status was assessed serologically by a specific response to 11 common inhalant allergens by using serum samples obtained from the women during the period 1997 to 2001. Information on allergic rhinitis and asthma was available from telephone interviews.

RESULTS

We found no association between having been vaccinated against smallpox in childhood and risk of atopy or allergic rhinitis. Smallpox vaccination was associated with a slightly decreased risk of asthma. There was no association between age at smallpox vaccination and risk of atopy, allergic rhinitis, or asthma. Adjusting for birth cohort, sibship size, age of the woman's mother at birth, and social class in childhood did not change these results.

CONCLUSION

Our findings do not suggest that childhood vaccination against smallpox, even if given early in life, influences the development of atopy or allergic rhinitis. The association with asthma should be interpreted with caution and needs further study.

Is the prevalence of adult asthma and allergic rhinitis still increasing? Results of an Italian study

BACKGROUND

The prevalence of asthma and allergic rhinitis has increased worldwide during the 1970s and 1980s.

OBJECTIVE

This study was aimed at evaluating whether the increasing trend in prevalence persisted during the 1990s in the young adult Italian population.

METHODS

In 1998 to 2000 a screening questionnaire was sent by mail to a general population sample aged 20 to 44 years; nonresponders were contacted again first by mail and then by phone, achieving a final response rate of 78.1% (6876 of 8800). Prevalence estimates, adjusted to correct for nonresponse bias, were compared with those recorded in Italy in 1991 to 1993 during the European Community Respiratory Health Survey, when response rate had been slightly higher (87.6%). Temporal variations in symptom prevalence were analyzed by a logistic regression model, controlling for sex, age, site of residence (urban vs suburban areas), season of response, response rate, and type of contact (mail vs phone).

RESULTS

The prevalence of asthma attacks did not vary significantly from 1991 to 1993 (3.6%) to 1998 to 2000 (3.2%) (P =.188). The prevalence of asthma-like symptoms (wheezing, chest tightness, shortness of breath) tended to decrease in the age classes of 32.5 to 45 years, while increasing in the youngest age class (20 to 26 years). A clear-cut increase from 15.4% to 18.3% was observed for the prevalence of allergic rhinitis (P <.001), whereas the proportion of people under antiasthmatic treatment increased in suburban areas but not in urban areas (interaction time-site of residence, P <.001).

CONCLUSION

Asthma prevalence has not increased during the last decade in Italy. The persistence of an increasing trend in allergic rhinitis prevalence deserves attention.

Age at childhood infections and risk of atopy

BACKGROUND

It has been proposed that early age at exposure to common childhood infections is associated with a decreased risk of allergy. Previous studies on the possible association between allergy and infection with measles, mumps, rubella, and varicella have not been conclusive as most did not include information on exact age at exposure. The objective of our study was to investigate whether early age at exposure to these infections was associated with a decreased risk of atopy using information on exact age at infection.

METHODS

The study population consisted of 889 pregnant women who participated in a national birth cohort study in Denmark and for whom detailed information on history of measles, rubella, varicella, and mumps before school entry (age 7 years) was available from school health records from Copenhagen. Atopic status was assessed serologically by a specific response to 11 common inhalant allergens using serum samples obtained from the women during pregnancy.

RESULTS

Measles in the first year of life was associated with a higher risk of atopy than no measles before age 7 years (OR 3.36, 95% CI 1.47 to 7.68). There was no association between atopy and mumps, rubella, or varicella in the first 7 years of life or with measles acquired after the first year of life. The risk of atopy increased significantly with increasing number of childhood infections in the first 2 years of life (p(trend)=0.01).

CONCLUSIONS

These findings do not support the suggestion that childhood exposure to measles, rubella, varicella, or mumps protects against atopy, even if acquired very early in life.

Atopic sensitization among children in an arctic environment

BACKGROUND

Asthma has been reported to be rare among Inuits, but so far total and specific IgE levels have never been determined in arctic populations.

OBJECTIVE

To determine the prevalence of atopy in children living in an arctic environment, and to examine whether atopy and total IgE levels were associated with parental place of birth, as a measure of ethnicity, and travel history.

MATERIAL AND METHODS

All schoolchildren in Sisimiut, a community on the West coast of Greenland, were screened for atopy. Blood samples were analysed for total IgE and for specific IgE against inhalant and food allergens. Information on place of birth of children and their parents was obtained from national registries. Information on travel history was obtained from self-administered questionnaires.

RESULTS

A total of 1031 schoolchildren aged 5 to 18 years had a blood sample drawn (85% of available children for the study). Of these, 151 (14.6%) children were sensitized to at least one inhalant allergen and 42 (4.1%) to at least one food allergen. Sensitization to grass was most common, whereas sensitization to mugwort, birch, animal-dander and house-dust mite was infrequent. Children whose parents were both born abroad had a higher risk of sensitization to inhalant allergens compared with children born of Greenlandic parents (OR = 8.6, 95% CI 2.8-27.1). Furthermore, children who had been abroad had a higher risk of sensitization towards pollen (OR = 1.6, 95% CI 1.0-2.5) and animal-dander (OR = 2.1, 95% CI 1.0-4.6) after adjustment for confounders. Both atopic and non-atopic children demonstrated high levels of total IgE (medians of 251 and 58 kU/L).

CONCLUSIONS

Compared with European findings Greenlandic children have high levels of total IgE but a low prevalence of allergic sensitization towards inhalant allergens. This may be due to a low genetic susceptibility to atopy and less allergen exposure, as well as to living conditions in an arctic environment.

Prevalence and differential diagnosis of chronic rhinitis

The prevalence and differential diagnosis of rhinitis changes as we progress from birth to senescence. The heavy burden of allergic rhinitis is often overlooked in infants and disregarded in childhood and adolescence. In women, especially during pregnancy, hormonal changes can significantly affect nasal mucosal hyperreactivity and worsen ongoing syndromes. Various types of inflammatory and noninflammatory nonallergic rhinitides become more prevalent in the fifth decade and beyond. The burgeoning elderly population with irritant, atrophic, and medication-related rhinitis will constitute a greater proportion of our practices as the general population ages.

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.

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.