Longitudinal study of grass pollen exposure, symptoms, and exhaled nitric oxide in childhood seasonal allergic asthma

BACKGROUND: Exhaled nitric oxide (NO) has been proposed as a marker of airway eosinophilic inflammation in asthma. There is currently a paucity of longitudinal data relating it to allergen exposure and asthma symptoms. METHODS: Forty four children (6-16 years) with seasonal allergic asthma were sequentially followed before and during the grass pollen season. Asthma symptoms, lung function, NO levels, and pollen counts were recorded. The relationship between exhaled NO and both the pollen levels and asthma control were assessed longitudinally, comparing a subject's measurements with their previous ones. RESULTS: The median exhaled NO concentration was significantly increased during the pollen season (6.2 v 9.2 parts per billion (ppb), p<0.002; median change 2.9 ppb, 95% confidence interval 1.5 to 5.4). Exhaled NO was best associated with the mean pollen count in the week before measurement. It was also significantly associated with asthma control. CONCLUSIONS: The results suggest that, within a longitudinal model, the exhaled NO concentration is related to preceding allergen exposure and asthma control. It may be clinically more useful to compare exhaled NO values with a subject's previous values than to compare them with a population based normal range.     

Effect of natural allergen exposure during the grass pollen season on airways inflammatory cells and asthma symptoms.

BACKGROUND: Bronchial challenge with allergen causes a specific form of airways inflammation consisting of an influx of neutrophils, eosinophils, and T cells. Because the relevance of the challenge model to clinical asthma is uncertain, the cellular changes that occur in the lungs of asthmatic subjects during natural seasonal allergen exposure were investigated. METHODS: Seventeen grass pollen sensitive asthmatic subjects with previously reported seasonal exacerbations of asthma kept records of symptoms and underwent fibreoptic bronchoscopy with bronchoalveolar lavage (BAL) and endobronchial biopsy before and during the peak of the grass pollen season. The BAL cells were analysed for differential cell counts and by flow cytometry for T cell subsets and surface activation markers. The biopsy samples were processed into glycol methacrylate resin and immunohistochemical analysis was performed for mast cells, activated eosinophils, T cells and interleukin 4 (IL-4), a cytokine with a pivotal role in allergen-induced inflammation. RESULTS: In the pollen season there was an increase in T lymphocyte activation in the BAL fluid as identified by increased expression of interleukin 2 receptor (IL-2R). In the submucosa these changes were paralleled by an increase in CD4+ T cells. By contrast, the numbers of metachromatic cells in BAL fluid staining with toluidine blue were reduced, possibly because of degranulation following allergen stimulation. In keeping with mast cell activation, the number of mucosal mast cells staining for secreted IL-4 increased during the season. In comparison with the period shortly before the onset of the season, all but two subjects experienced an asthma exacerbation which followed the rise in pollen counts but, compared with the period preceding the first bronchoscopic examination, asthma symptoms were not increased during the pollen season. CONCLUSIONS: The data suggest that natural allergen exposure, leading to a clinical exacerbation of asthma, may induce an inflammatory response involving T cells, mast cells and eosinophils. The relationship between allergen exposure, cellular infiltration and activation, and clinical symptoms appears to be complex, with factors other than allergen also contributing to asthmatic activity.     

Geographical and socioeconomic variation in the prevalence of asthma symptoms in English and Scottish children.

BACKGROUND: There has been controversy over the relation between poverty and asthma in the community. The aim of this analysis was to disentangle geographical and socioeconomic variation in asthma symptoms. METHODS: The analysis is based on parental reports of symptoms from data collected in 1990 and 1991. Children aged 5-11 years from three populations (English representative sample, Scottish representative sample, and an English inner city sample) were included. Of 17 677 eligible children, between 14 490 (82.0%) and 15 562 (88.0%) children were available for analysis according to symptom group. RESULTS: Wheezy symptoms were less prevalent in the Scottish sample than in the English samples and asthma attacks were most prevalent in the English representative sample. Asthma attacks were less prevalent in inner city areas than in the English representative sample (OR 0.79, 95% CI 0.66 to 0.95), but persistent wheeze and other respiratory symptoms were more prevalent (OR 1.95, 95% CI 1.65 to 2.32 and OR 1.67, 95% CI 1.52 to 1.84, respectively). The prevalence of persistent wheeze was higher in children whose father's social class was low and in those living in areas with a high Townsend score (an index of poverty) than in other children (p<0.001). Of the 14 areas with the highest Townsend score, 13 had an OR above 1 and six had an OR significantly higher than the reference area. CONCLUSIONS: Persistent wheeze is more prevalent in poor areas than in less deprived areas. This may indicate that poverty is associated with severe asthma or that a high percentage of persistent asthma symptoms in inner city areas are unrecognised and untreated.     

Early allergen exposure, skin prick responses, and atopic wheeze at age 5 in English children: a cohort study

BACKGROUND: For many years it has been assumed that the risk of childhood respiratory allergies is related to allergen exposures in early life. There are, however, few prospective data in support. We aimed to examine this relationship in a representative cohort of children born in Ashford, Kent (UK). METHODS: 625 children (94% of those eligible) were followed from birth to the age of 5.5 years at which time 552 underwent skin prick testing to extracts of house dust mite and cat fur allergens. Maternal reports of wheeze in the last year were collected by interview. These outcomes were related to individual domestic concentrations of Der p 1 and Fel d I allergens estimated from dust collection at the age of 8 weeks. RESULTS: 10% of children were sensitised to house dust mite or cat at age 5.5 years; 7% had atopic wheeze. No significant relationships between allergen exposure and either sensitisation or wheeze were found but, on examination, the exposure-response relationships for both allergens and for each outcome rose steeply at low levels of exposure and were attenuated at high levels of exposure. These patterns were modified by paternal atopy and by birth order. CONCLUSIONS: There are no linear relationships between early allergen exposure and the induction of childhood respiratory allergy; rather, the risks of IgE sensitisation and asthma rise at very low levels of exposure and are attenuated thereafter. These patterns are influenced by parental atopy and birth order. These findings suggest important gene-environment interactions in the development of atopy and asthma and imply that reductions in domestic allergen exposure alone are unlikely to have a major impact in decreasing the incidence of these diseases in childhood.     

Increasing prevalence of asthma diagnosis and symptoms in children is confined to mild symptoms

BACKGROUND: The prevalence of childhood asthma is increasing but few studies have investigated trends in asthma severity. We investigated trends in asthma diagnosis and symptom morbidity between an eight year time period in a paired prevalence study. METHODS: All children in one single school year aged 8-9 years in the city of Sheffield were given a parent respondent questionnaire in 1991 and 1999 based on questions from the International Survey of Asthma and Allergy in Children (ISAAC). Data were obtained regarding the prevalence of asthma and wheeze and current (12 month) prevalences of wheeze attacks, speech limiting wheeze, nocturnal cough and wheeze, and exertional symptoms. RESULTS: The response rates in 1991 and 1999 were 4580/5321 (85.3%) and 5011/6021 (83.2%), respectively. There were significant increases between the two surveys in the prevalence of asthma ever (19.9% v 29.7%, mean difference 11.9%, 95% confidence interval (CI) 10.16 to 13.57, p<0.001), current asthma (10.3% v 13.0%, mean difference 2.7%, 95% CI 1.44 to 4.03, p<0.001), wheeze ever (30.3% v 35.8%, mean difference 5.7%, 95% CI 3.76 to 7.56, p<0.001), wheeze in the previous 12 months (17.0% v 19.4%, mean difference 2.5, 95% CI 0.95 to 4.07, p<0.01), and reporting of medication use (16.9% v 20%, mean difference 3.0%, 95% CI 1.46 to 4.62, p<0.001). There were also significant increases in reported hayfever and eczema diagnoses. CONCLUSIONS: Diagnostic labelling of asthma and lifetime prevalence of wheeze has increased. The current 12 month point prevalence of wheeze has increased but this is confined to occasional symptoms. The increased medication rate may be responsible for the static prevalence of severe asthma symptoms. The significant proportion of children receiving medication but reporting no asthma symptoms identified from our 1999 survey suggests that some children are being inappropriately treated or overtreated.     

Labelling of rhinitis and hayfever by doctors

Factors influencing the labelling of rhinitis by doctors were examined in 7702 adults, aged 16-65 years, registered with a group general practice in south London. Individuals with rhinitis were identified by a postal screening questionnaire. Of the 2969 (39%) subjects who replied, 1309 (44%) reported rhinitis. A sample of 340 individuals with and 126 without rhinitis was studied, each being interviewed and having allergy skinprick tests. The information given at interview was compared with that recorded in the medical notes for 75 patients with rhinitis, selected at random to include 25 with seasonal symptoms only, 25 with perennial symptoms only, and 25 with both seasonal and perennial symptoms, plus 25 control subjects. Hayfever was defined as seasonal symptoms provoked by grass and a positive skin test response to grass pollen. Subjects with seasonal symptoms were nearly twice as likely as those with perennial symptoms to be labelled as having rhinitis by their doctor. More than a quarter of the subjects fulfilling our definition of hayfever had not been diagnosed as having hayfever. Subjects from the upper social classes were more likely than those from the lower social classes to be labelled as having hayfever, though there were no significant differences between social classes in the prevalence of hayfever according to our definition. It is concluded that rhinitis is frequently underdiagnosed and misdiagnosed. Increased detection of hayfever could account for the steep rise in consultation rates seen in recent decades.     

Chronic rhinosinusitis: Allergy and sinus computed tomography relationships

The management of chronic or recurrent rhinosinusitis problems is multifaceted and should include consideration of contributory and potentially correctable medical and anatomic factors. To date, the relationship between allergy and rhinosinusitis has not been clearly defined. The purpose of this study is to improve understanding of the relative roles of perennial and seasonal allergens in the cause of chronic rhinosinusitis. A retrospective review of 200 consecutive patients was carried out on patients who had chronic rhinosinusitis refractory to medical therapy and who subsequently underwent functional endoscopic sinus surgery. All of these patients had allergy testing for common perennial and seasonal inhalant allergens before surgery. Each patient had sinus CT imaging before undergoing the surgery. The CT scans of each patient were staged according to a validated, standardized grading system by investigators blinded to allergic profile. Allergy testing indicated that 84% of all patients tested positive for allergies. Moreover, 60% of all patients had significant allergic sensitivity; 52% of all patients had multiple allergen sensitivities. Furthermore, there was a predominance of perennial allergens, especially house dust mite over seasonal allergens. The vast majority of our patients undergoing functional endoscopic sinus surgery had concomitant allergy. This study highlights the potential contribution of perennial allergies to the development of rhinosinusitis. Given this direction, future studies may reveal that in the care of patients with perennial allergic rhinitis, early intervention with identification of the offending allergen(s), and subsequent treatment through avoidance, pharmacotherapy, and/or immunotherapy may help in the prevention of recurrent and chronic rhinosinusitis.     

Exhaled nitric oxide levels in atopic children: relation to specific allergic sensitisation,AHR, and respiratory symptoms

BACKGROUND: Exhaled nitric oxide (eNO), which has been proposed as a measure of airway inflammation, is increased in atopic subjects. This raises the question of whether eNO provides any additional information about airway inflammation in asthmatic subjects, other than as a marker for atopy. A study was undertaken to determine whether eNO levels in a population of atopic children are associated with sensitisation or natural exposure to specific allergens, and to examine the relationship between eNO, airway responsiveness, and current respiratory symptoms. METHODS: Exhaled NO and airway responsiveness to histamine were measured in winter and in summer in 235 children aged 8-14 years who had been classified as atopic by skin prick testing. Current respiratory symptoms, defined as wheeze or cough during the month preceding the test, were measured by a parent completed questionnaire. Airway hyperresponsiveness (AHR) was defined as a dose response ratio (DRR) of >8.1 (% fall in forced expiratory volume in 1 second (FEV(1))/micromol + 3). RESULTS: Sensitisation to house dust mite was associated with raised eNO levels in winter while sensitisation to Cladosporium was associated with raised eNO levels in both winter and summer. Grass pollen sensitisation was not associated with raised eNO levels in either season. Exhaled NO correlated significantly with DRR histamine (r=0.43, p<0.001) independently of whether the children had current symptoms or not. In children with current wheeze, those with AHR had eNO levels 1.53 (95% CI 1.41 to 1.66) times higher than those without AHR (p=0.006). Neither DRR (p=1.0) nor eNO levels (p=0.92) differed significantly between children with or without persistent dry cough in the absence of wheeze. CONCLUSIONS: In atopic children, raised eNO levels are associated with sensitisation to perennial allergens, but not to seasonal allergens such as grass pollen. In this population, an increase in eNO is associated with AHR and current wheezing, suggesting that eNO is more than just a marker for atopy.     

Prevalence of allergy in patients with chronic rhinosinusitis.

OBJECTIVES: The purpose of this study was to provide further evidence that allergic rhinitis is an important factor in chronic and recurrent acute rhinosinusitis. Specifically, this study shows that perennial allergens play a more significant role than seasonal allergens. STUDY DESIGN AND SETTING: Census by chart review of patients with chronic and recurrent acute rhinosinusitis presenting to the Department of Otolaryngology at the MetroHealth Medical Center, Cleveland, OH. METHODS: All participants had allergy testing done either by RAST or intradermal skin endpoint titration utilizing a battery of seasonal and perennial antigens. RESULTS: Of the 48 voluntary participants analyzed in this study, 57.4% had a positive allergy test. Most patients in the study were sensitive to more than one allergen. Of the patients with a positive allergy test, 92% demonstrated sensitivity to one or more perennial allergens-most prominently, molds and dust mites. CONCLUSIONS: Perennial allergy has a statistically significant association with chronic and recurrent acute rhinosinusitis. SIGNIFICANCE: The diagnosis and management of perennial allergies may be beneficial when treating chronic sinus disease.     

Use of modified radioallergosorbent testing in determining initial immunotherapy doses

Proponents of the modified radioallergosorbent test (RAST) for allergy diagnosis claim an advantage over skin testing in that immunotherapy may often be safely begun at higher initial concentrations and maintenance achieved with fewer injections than with conventional schedules. The resulting fewer visits would offset the greater initial cost and the delay in obtaining results. The most important allergen for 58 consecutive patients with seasonal allergic rhinitis beginning immunotherapy was determined from the history, skin testing, and aeroallergen surveys. A modified RAST was performed for these allergens. Thirty-nine patients (67%) had a modified RAST class 5 (most severe); 18 patients (31%) were class 4, and one patient was class 3. Since the initial concentration and total number of injections projected to reach maintenance vary little between our conventional schedule (1:100,000 w/v, 23 injections), and those for class 5 (1:62,500 w/v, 27 injections) and class 4 (1:12,500 w/v, 21 injections), the modified RAST offers no advantage over skin testing and conventional immunotherapy dosing in our patient population.     

Feasible and simple exclusion criteria for pulmonary reference populations

BACKGROUND: International guidelines recommend that pulmonary reference populations consist of never-smokers without respiratory diseases or symptoms, but the diseases and symptoms are not clearly specified. The present study aimed to identify simple exclusion criteria for defining pulmonary reference populations. METHODS: Based on a random sample from a general population (the parent population), 2,358 subjects aged 26-82 years performed spirometric tests. From this sample, subjects were stepwise excluded according to self-reported obstructive lung diseases, symptoms and smoking history. Four increasingly more healthy respiratory reference populations were formed. Prediction equations for the median and lower limit of normal lung function were derived using quantile regression analysis. RESULTS: Subjects without self-reported obstructive lung diseases or the cardinal respiratory symptoms of breathlessness, cough or wheeze (population B), never-smokers without cardinal symptoms (population C) and never-smokers without any respiratory symptoms (population D) constituted 50% (n = 1,184), 23% (n = 539) and 14% (n = 331) of the parent population (population A), respectively. The largest discrepancy between prediction equations was found between the parent population and the population without cardinal respiratory symptoms (population B) (p<0.05). Minor changes in the reference equations were also seen when excluding ever-smokers (population C). There was no additional change with exclusion of other respiratory symptoms (population D). Age-related decline in lung function was steepest in the parent population. CONCLUSIONS: Obstructive lung diseases, smoking history, breathlessness, cough and wheeze are optimal exclusion criteria for a pulmonary reference population. Further validation of the exclusion criteria identified in this study is recommended with identical wording in other and larger multinational populations.     

Inhalant allergy and Meniere's disease: Use of electrocochleography and intranasal allergen challenge as investigational tools.

INTRODUCTION: In an earlier study, we demonstrated the feasibility of using electrocochleography (ECoG) to document changes in inner ear function objectively after intranasal challenge of patients with inhalant allergy (with no prior immunotherapy) and Meniere's disease, using the antigen to which they were most sensitive. OBJECTIVE: We expand on this earlier study and continue to investigate the feasibility of this model in a subset of patients with inhalant allergy and Meniere's disease after immunotherapy. STUDY DESIGN: Prospective study of 11 patients identified with both Meniere's disease and inhalant allergy in the practices of 2 neurotologists at our institution. Patients underwent a baseline ECoG, followed by intranasal challenge with the allergen to which they were most sensitive. This was followed by a second ECoG. RESULTS: Six of 11 patients had at least 1 year of immunotherapy (group 1), and 5 of 11 had had 0 to 6 months of immunotherapy (group 2). Four of 6 group 1 patients had a >15% increase in SP/AP ratio after immunotherapy. In group 2, 2 patients increased the SP/AP in at least 1 ear. No patient with a normal ECoG experienced vestibular symptoms after allergen challenge, whereas 2 of group 1 and 2 of group 2 had vestibular symptoms with abnormal ECoGs. CONCLUSION: This protocol is a useful tool for investigating the relationship of inhalant allergy and Meniere's disease, but needs a larger group of patients and further study to draw valid statistical conclusions.     

Asthma, allergy, and atopy in three south-east Asian populations.

BACKGROUND--Whilst many recent reports have suggested a rise in the prevalence of asthma and allergic disease in Western countries, little is known about the epidemiology of these common conditions in south-east Asia. This study compared the prevalence of asthma and allergic disease amongst secondary school students in three south-east Asian populations--Hong Kong, Kota Kinabalu in Malaysia, and San Bu in China--and investigated the associations with atopy and family history. METHODS--Secondary school students were given standard questionnaires on respiratory and allergic symptoms for completion by parents with response rates of 89.2% in Hong Kong (611 male, 451 female; mean (SD) age = 13.9 (1.8 years), 87.6% in Kota Kinabalu (134 male, 275 female; 15.5 (2.1) years), and 98.6% in San Bu (492 male, 245 female; 16.4 (1.8) years). Skin tests were performed in a subsample of students to determine atopic status. RESULTS--The respective prevalence (and 95% CI) for hayfever, eczema, and wheeze or asthma were 15.7% (13.5, 17.9), 20.1% (17.7, 22.5), 11.6% (9.3, 13.9) in Hong Kong, 11.2% (8.2, 14.3), 7.6% (5.0, 10.1), 8.2% (5.5, 10.9) in Kota Kinabalu, and 2.1% (1.2, 3.1), 7.2% (5.4, 9.1), 1.9% (0.7, 3.1) in San Bu. Atopy was common and was present in 49.0-63.9% of subjects in the three populations. Dust mite and cockroach were the commonest allergens that gave positive reactions in 42.8-60.5% and 25.7-35.9% of students respectively. A higher proportion of students in Hong Kong had severe degree of reactivity on skin test than the other two populations. Family history was associated with asthma and allergic symptoms in the three populations conferring a 3-80-fold increase in risk to family members and was a stronger predictor for asthma and allergy than atopy. CONCLUSIONS--Prevalence of asthma and allergic disease is low compared with Western countries, but considerable differences exist between the three south-east Asian populations despite similar rates of atopy. Asthma and allergic disease are more strongly associated with family history than atopy, which suggests that genetic and environmental factors common to the family, other than aeroallergen sensitisation, are important in the pathogenesis of asthma and allergy in the region.     

Trends in the prevalence of respiratory symptoms and treatment in Dutch children over a 12 year period: results of the fourth consecutive survey

BACKGROUND: Although there is considerable evidence that the prevalence of childhood asthma has increased over the last decades, it is not clear if this trend is still ongoing. A study was undertaken to investigate whether previously observed trends in the prevalence of respiratory symptoms, physician visits, medication use, and absence from school in Dutch children aged 8-9 years persisted in 2001. METHODS: Parents of 1154 children aged 8-9 years eligible for a routine physical examination in 2001 were asked to complete a questionnaire on the respiratory health of their child. RESULTS: In 2001, 1102 children (95.5%) participated in the survey. Similarly high response rates were obtained in the surveys of 1989, 1993 and 1997, with 1794, 1526 and 1670 children aged 8-9 years participating in the respective surveys. The decreasing trend previously observed for recent wheeze between 1989 and 1997 persisted into 2001, particularly in boys. After increasing between 1989 and 1997, the prevalence of shortness of breath with wheeze decreased between 1997 and 2001. The proportion of wheezy children using medication increased between 1989 and 2001 in boys (42.9% v 64.8%; p = 0.003), but the increase was not statistically significant in girls (34.0% v 45.7%; p = 0.096). CONCLUSION: The prevalence of recent wheeze in Dutch school children has declined steadily since 1989. The rising prevalence of medication use in symptomatic children over time may reflect better asthma control and may partly explain the concurrently decreasing trend in the prevalence of asthma symptoms in our study population.     

Quantification of airborne moulds in the homes of children with and without wheeze.

A population survey of 1000 7 year old children found a significant excess of wheeze among children whose homes were reported to be mouldy (odds ratio 3.70, 95% confidence limits 2.22, 6.15). The airborne mould flora was quantified by repeated volumetric sampling during the winter in three rooms of the homes of 88 children. All of these had previously completed spirometric tests before and after a six minute free running exercise challenge. Total airborne mould counts varied from 0 to 41,000 colony forming units (CFU)/m3, but were generally in the range 50-1500 CFU/m3, much lower than the concentrations found outdoors in summer. The principal types of fungi identified are all known to be common out of doors, and most were found on at least one occasion in most of the homes. Median and geometric mean total mould counts were not related to reports of visible mould in the home, or to a history of wheeze in the index child. The heterogeneous group of non-sporing fungi (mycelia sterilia) were the only airborne fungi present at significantly higher concentrations in the homes of wheezy children (geometric mean 2.1 v 0.7 CFU/m3. A non-significant increase in total mould counts was observed in the homes of children with a 10% or greater decline in FEV1 after exercise (geometric mean 354 v 253 CFU/m3). Questionnaire reports of mould in the home may be a poor indicator of exposure to airborne spores. The total burden of inhaled mould spores from indoor sources is probably not an important determinant of wheeze among children in the general population. Although the association with mycelia sterilia could be a chance finding, these non-sporing isolates may include a potent source of allergen.     

Lower respiratory tract symptoms in Queensland schoolchildren: risk factors for wheeze, cough and diminished ventilatory function.

BACKGROUND--The occurrence of respiratory symptoms and abnormal lung function in children is known to be influenced by genetic and many environmental factors. The association between specific respiratory symptoms in children of school age and their parents has been examined. METHODS--Respiratory symptoms and ventilatory function were recorded for 4549 schoolchildren in Queensland, Australia. RESULTS--The cumulative prevalence of wheezing was 23.1% of 8 year olds and 20.8% of 12 year olds, and the prevalence of wheezing within the previous 12 months was 13.9% and 10.5% respectively. A parental history of asthma or wheeze and hayfever was associated with wheeze in the child, but did not affect either the age of onset or frequency of episodes. A history of frequent cough in children who had never wheezed was associated with a parental history of frequent bronchitis, but less strongly with parental wheeze. These familial aggregations were not mediated by common exposure to cigarette smoke. Both a history of parental wheeze and maternal cigarette use were associated with a decrease in FEF25-75 in the child and these effects were additive. CONCLUSIONS--The association of specific symptoms (wheeze and cough without wheeze) in parent and offspring is interpreted as evidence for different mechanisms of familial transmission, which may be genetic.     

Diagnostic and treatment behaviour in children with chronic respiratory symptoms: relationship with socioeconomic factors

BACKGROUND: The prevalence and severity of asthma is believed to increase with increasing socioeconomic deprivation. The relationship between asthma diagnosis, symptoms, diagnostic accuracy, and socioeconomic deprivation as determined by Townsend scores was determined in Sheffield schoolchildren. METHODS: All 6021 schoolchildren aged 8-9 years in one school year in Sheffield were given a parent respondent survey based on International Survey of Asthma and Allergies in Childhood (ISAAC) questions. RESULTS: 5011/6021 (83.2%) questionnaires were returned. Postcode data were available in 4131 replies (82.4%) and were used to assign a composite deprivation score (Townsend score). Scores were divided into five quintiles, with group 1 being least and group 5 being most deprived. A positive trend was observed from group 1 to group 5 for the prevalence of wheeze in the previous 12 months, wheeze attacks >or=4/year, nocturnal wheeze and cough (all p<0.001), cough and/or wheeze "most times" with exertion (p<0.03), current asthma (p<0.001), and significant asthma symptoms (p<0.001). No significant trend was observed for lifetime wheeze or attacks of speech limiting wheeze. There were no significant trends in the prevalence of current asthmatic children without significant symptoms (overdiagnosis) or children with significant asthma symptoms but no current asthma diagnosis (underdiagnosis) across the social groups. There was a significant negative trend in the ratio of asthma medication to asthma diagnosis from least to most deprived groups (p<0.001). CONCLUSIONS: Asthma morbidity and severity increase according to the level of socioeconomic deprivation. This may be due to differences in environment, asthma management, and/or symptom reporting. Diagnostic accuracy does not vary significantly across deprivation groups but children living in areas of least deprivation and taking asthma medication are less likely to be labelled as having asthma, suggesting diagnostic labelling bias.     

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.     

Epidemiology of seasonal and perennial rhinitis: clinical presentation and medical history.

BACKGROUND: Little is known about the epidemiology of rhinitis, particularly the perennial and non-allergic forms. The aim of this study was to compare the symptoms, atopic state, and medical history of individuals with seasonal and perennial rhinitis. DESIGN: Of 7702 adults aged 16-65 years registered with a London general practice, 2969 (30%) were screened by postal questionnaire. Samples of 113 subjects without rhinitis, 51 with seasonal symptoms alone, 128 with perennial symptoms and seasonal exacerbations were then interviewed. Atopic and non-atopic subjects were distinguished by skinprick testing with five common allergens. RESULTS: The estimated minimum prevalence of rhinitis was 24%: 3% had seasonal symptoms only, of whom 78% were atopic; 13% had perennial symptoms only, of whom 50% were atopic; and 8% had perennial symptoms with seasonal exacerbations, of whom 68% were atopic. Seasonal rhinitis was characterised by sneezing, itching, and a high prevalence of diurnal variation in symptoms. The most common provoking factors were dust, pollens, and infections. By comparison, perennial rhinitis was characterised by a higher prevalence of nasal blockage and catarrh, and a lower prevalence of diurnal variation and provocation by pollen. There were no significant differences among the groups in the sociodemographic characteristics examined. Subjects with seasonal rhinitis were more likely to be atopic and to have eczema and a family history of hayfever than those without rhinitis. Those with perennial rhinitis were more likely to have past or current eczema or migraine, be wheezy or labelled asthmatic, or have a family history of nose trouble other than hayfever. Subjects with both seasonal and perennial symptoms presented an intermediate clinical picture. CONCLUSIONS: Seasonal and perennial rhinitis differ in their atopic state, clinical presentation, and medical history. The extent to which these differences are genetically or environmentally determined requires further investigation.     

Association of asthma and hay fever with irregular menstruation

BACKGROUND: There is some evidence that asthmatic women are more likely to have abnormal sex hormone levels. A study was undertaken to determine whether asthma and allergy were associated with irregular menstruation in a general population, and the potential role of asthma medication for this association. METHODS: A total of 8588 women (response rate 77%) participated in an 8 year follow up postal questionnaire study of participants of the ECRHS stage I in Denmark, Estonia, Iceland, Norway, and Sweden. Only non-pregnant women not taking exogenous sex hormones were included in the analyses (n = 6137). RESULTS: Irregular menstruation was associated with asthma (OR 1.54 (95% CI 1.11 to 2.13)), asthma symptoms (OR 1.47 (95% CI 1.16 to 1.86)), hay fever (OR 1.29 (95% CI 1.05 to 1.57)), and asthma preceded by hay fever (OR 1.95 (95% CI 1.30 to 2.96)) among women aged 26-42 years. This was also observed in women not taking asthma medication (asthma symptoms: OR 1.44 (95% CI 1.09 to 1.91); hay fever: OR 1.27 (95% CI 1.03 to 1.58); wheeze preceded by hay fever: OR 1.76 (95% CI 1.18 to 2.64)). Irregular menstruation was associated with new onset asthma in younger women (OR 1.58 (95% CI 1.03 to 2.42)) but not in women aged 42-54 years (OR 0.62 (95% CI 0.32 to 1.18)). The results were consistent across centres. CONCLUSIONS: Younger women with asthma and allergy were more likely to have irregular menstruation. This could not be attributed to current use of asthma medication. The association could possibly be explained by common underlying metabolic or developmental factors. The authors hypothesise that insulin resistance may play a role in asthma and allergy.