Worldwide variations in prevalence of symptoms of allergic rhinoconjunctivitis in children: the International Study of Asthma and Allergies in Childhood (ISAAC)

Food hypersensitivity in patients with seasonal rhinitis in Ankara

BACKGROUND

Food hypersensitivity (FH) affects 1-2 % of the adult population and is more common in atopic individuals. The aim of this study was to determine the frequency of FH and risk factors for its development in patients with seasonal rhinitis (SR) in our allergy clinic.

METHODS

We performed a retrospective study based on the medical records of 774 patients out of 955 patients diagnosed with SR in an adult allergy clinic between 1 January 1991 and 31 December 2003.

RESULTS

The mean age of the patients was 29.1 +/- 9.29 and 62.7 % were females. The most common major complaints were due to nasal symptoms in 82.3 %. The mean duration of SR was 6.8 +/- 6.8 years. Patients were symptomatic for a mean of 3.5 +/- 1.7 months per year. Skin prick tests (SPT) with common aeroallergens were positive in 685 patients (90.3 %), and the most common sensitivity was against timothy (85.1 %). The most common accompanying allergic disease was FH in 14 %. FH according to history and the results of SPT performed with food allergens were discordant. The most common clinical manifestations of FH were oral allergy (49.1 %) and cutaneous symptoms (38.9 %). Risk factors for the development of FH in patients with SR were dermatological symptoms, rhinitis duration > 5 years, symptom duration > 3 months per year, SPT reactivity to Artemisia vulgaris, tree pollen allergens (Corylus avellena, Betula verrucosa), and bee allergy.

CONCLUSION

FH was the most common (14 %) accompanying allergic disease in patients with SR. SPT with food allergens have limited diagnostic value for food allergy and/or intolerance. Risk factors for developing FH in patients with SR in Turkey were dermatological symptoms, duration of rhinitis > 5 years, duration of rhinitis symptoms > 3 months per year, and SPT reactivity to Corylus avellena.

Association between allergic rhinitis and hospital resource use among asthmatic children in Norway

BACKGROUND

Preliminary evidence suggests that inadequately controlled allergic rhinitis in asthmatic patients can contribute towards increased asthma exacerbations and poorer symptom control, which may increase medical resource use. The objective of this study was therefore to assess the effect of concomitant allergic rhinitis on asthma-related hospital resource utilization among children below 15 years of age with asthma in Norway.

METHODS

A population-based retrospective cohort study of children (aged 0-14 years) with asthma was conducted using data from a patient-specific public national database of hospital admissions during a 2-year period, 1998-1999. Multivariate linear regression, adjusting for risk factors including age, gender, year of admission, urban/rural residence and severity of asthma episode, estimated the association between allergic rhinitis and total hospital days. A multivariate Cox proportional-hazards model estimated relative hazard of readmission according to concomitant allergic rhinitis status.

RESULTS

Among 2961 asthmatic children under 15 years of age with at least one asthma-related hospital admission over a 2-year period, 795 (26.8%) had a recorded history of allergic rhinitis. Asthmatic children with allergic rhinitis had a 1.72-times greater hazard of asthma-related readmissions than asthmatic children without allergic rhinitis. Multivariate analysis revealed that history of concomitant allergic rhinitis was a significant predictor of increased number of hospital days per year (least-squares mean difference 0.23 days, P < 0.05).

CONCLUSIONS

Concomitant allergic rhinitis in asthmatic children was associated with increased likelihood of asthma-related hospital readmissions and greater total hospital days.

Prevalence of allergy-related symptoms in Singaporean children in the second year of life

This study describes the cross-sectional prevalence of symptoms associated with eczema (chronic itchy rash), asthma (wheeze), and allergic rhinitis (rhinoconjunctivitis) in 1026 subjects between 18.5 and 23 months old (median age is 21 months) in Singapore. The first 2 yr cumulative prevalence of chronic itchy rash, wheeze, and rhinoconjunctivitis were 22.1% (n=227), 22.9% (n=235), and 8.4% (n=86) respectively. In total, 42.2% (414 of 979) reported ever having any of these symptoms. Eczema, although prevalent, was diagnosed only in 34.4% (n=78) of children with chronic itchy rash. Children with this eczematous rash were also more prone to wheeze (cOR=2.0, 95% CI: 1.2-3.0) and rhinoconjunctivitis (cOR=2.0, 95% CI: 1.4-2.8). Similarly, subjects who reported rhinoconjunctivitis and chronic itchy rash were 2.4 times (95% CI: 1.6-3.6) and 1.4 times (95% CI: 1.0-2.0) more at risk of wheezing respectively. Family history of allergy was a significant risk factor for chronic itchy rash (aOR=1.8, 95% CI: 1.3-2.4) and wheeze (aOR=1.7, 95% CI: 1.3-2.4). Thus, symptoms related to allergy were already prevalent during the second year of life. Significant proportions of these symptoms are likely to be due to true atopy as strong relationship with familial history and comorbidity with other potential allergic symptoms were observed.

Allergy and infectious disease histories and the risk of childhood acute lymphoblastic leukaemia

Infectious disease histories were evaluated in a population-based case-control study of childhood acute lymphoblastic leukaemia (ALL) as it has been hypothesised that delays in early infections are associated with an increased risk of disease. Allergy histories were also assessed as part of a broader evaluation of the role of immune factors in ALL. Cases (n = 255) were diagnosed between 1980 and 1991 at one of four referral centres in a 31-county area of New York State; controls (n = 760) were a random sample of live births from the same region, frequency matched to cases by sex, race and birth year. Data were collected by mailed questionnaire, completed by case and control parents in 1995. Allergy and infectious histories before the age at leukaemia diagnosis for cases and an equivalent age for controls were evaluated. The adjusted odds ratio and 95% confidence interval [CI] associated with a positive history of any allergy was 0.58 [95% CI 0.38, 0.88] compared with a negative allergy history. The occurrence of several common childhood illnesses before 25 months of age and ALL were assessed, with both weak positive and weak inverse associations observed. Overall, these analyses provide little support for the hypothesis that infection delay in early life is associated with an increased risk of ALL. Children with positive allergy histories reported significantly more infections than those with negative histories; however, effect modification of the infection-ALL associations by child allergy history was not observed. Nonetheless, these observations suggest the importance of assessing both allergy and infectious histories and their possible interactions when evaluating the association between these immune factors and childhood ALL.

Asthma-related health care resource use among asthmatic children with and without concomitant allergic rhinitis

OBJECTIVE

To determine the incremental effect of allergic rhinitis on health care resource use in children with asthma.

DESIGN

Population-based historical cohort study.

SETTING

Data in a general practice database in the United Kingdom during 1998 to 2001.

PATIENTS

Children 6 to 15 years old with asthma and with >or=1 asthma-related visits to a general practitioner (GP) during a 12-month follow-up period.

MAIN OUTCOME MEASURES

Asthma-related hospitalizations, GP visits, and prescription drug costs during the 12-month follow-up period for patients with and without comorbid allergic rhinitis.

RESULTS

Of 9522 children with asthma, 1879 (19.7%) had allergic rhinitis recorded in the GP medical records. Compared with children with asthma alone, children with comorbid allergic rhinitis experienced more GP visits (4.4 vs 3.4) and more of them were hospitalized for asthma (1.4% vs 0.5%) during the 12-month follow-up period. In multivariable regression analyses, comorbid allergic rhinitis was an independent predictor of hospitalization for asthma (odds ratio: 2.34; 95% confidence interval [CI]: 1.41-3.91) and was associated with increases in the number of asthma-related GP visits (mean increase: 0.53; 95% CI: 0.52-0.54) and asthma drug costs (mean increase pound: 6.7; 95% CI: 6.5-7.0). The association between allergic rhinitis and higher costs of prescriptions for asthma drugs was independent of asthma severity, measured indirectly by the intensity of use of asthma drugs.

CONCLUSIONS

Children with comorbid allergic rhinitis incurred greater prescription drug costs and experienced more GP visits and hospitalizations for asthma than did children with asthma alone. A unified treatment strategy for asthma and allergic rhinitis, as recommended by the Allergic Rhinitis and Its Impact on Asthma initiative, might reduce the costs of treating these conditions.

[Time trends in prevalence of symptoms of allergic rhinitis in 13-14 year-old schoolchildren in 8 areas of Spain between 1993-1994 and 2001-2002 according to the International Study of Asthma and Allergies in Childhood (ISAAC)]

BACKGROUND AND OBJECTIVE

Our goal was to estimate the time trends in the prevalence of symptoms of allergic rhinitis (AR) and its geographic variations.

POPULATION AND METHOD

During 2001-2002, the phase 3 of ISAAC study was carried out, and a comparison with the phase 1 (1993-1994) was done. This cross sectional study included 30,046 schoolchildren 13-14 years-old from 9 centers (Asturias, Barcelona, Bilbao, Cartagena, Castellon, Madrid, Pamplona, Valencia, and Valladolid). A questionnaire about rhinitis symptoms self-administered to schoolchildren was used at schools and institutes with a participation rate of 100% to 75.8%.

RESULTS

A divergent time trend of AR prevalence symptoms was observed with a decrease in Barcelona and Bilbao, a stabilization in Cartagena, Pamplona, and Valencia, and an increase in Castellon; Madrid and Valladolid; however, there was an overall increase in nasal allergy. The prevalence of rhinoconjunctivitis in the past year (Prevalence Ratio [PR] = 1,13; 95% Confidence Interval [CI], 1.07-1.19) and nasal allergy ever (PR = 1.22; 95% CI, 1.15-1.30) increased after adjusting for gender, center and season change. The prevalence of rhinoconjunctivitis and nasal allergy varied according to centres, Madrid, Asturias, Cartagena and Bilbao exhibiting the higher prevalence. Taken as a whole, these data indicate a middle prevalence of AR when compared with other countries following an ISAAC methodology.

CONCLUSIONS

Two patterns of time trend of prevalence of symptoms of AR were observed. The investigation of risk factors at local level could be important in order to undertake preventive measures.

Chemokine receptors: understanding their role in asthmatic disease

The incidence, prevalence, and severity of asthma have been increasing steadily in recent years. Prophylactic treatment of this disease and of episodic asthmatic flares is aimed at preventing excessive inflammation in lung tissue and airways. Because chemokines and chemokine receptors are critical mediators of leukocyte trafficking and recruitment, there is the potential to pharmaceutically target these proteins to regulate inflammation. Asthma-associated inflammation is characterized by the infiltration of eosinophils and T helper type 2 cells. Early studies investigated the role of chemokine receptors, which have been shown to predominate on these cell populations.

Cetirizine: a review of its use in allergic disorders

Cetirizine is a selective, second-generation histamine H1 receptor antagonist, with a rapid onset, a long duration of activity and low potential for interaction with drugs metabolised by the hepatic cytochrome P450 system. Cetirizine was generally more effective than other H1 receptor antagonists at inhibiting histamine-induced wheal and flare responses. Cetirizine is an effective and well tolerated agent for the treatment of symptoms of seasonal allergic rhinitis (SAR), perennial allergic rhinitis (PAR) and chronic idiopathic urticaria (CIU) in adult, adolescent and paediatric patients. In adults with these allergic disorders, cetirizine was as effective as conventional dosages of ebastine (SAR, PAR, CIU), fexofenadine (SAR), loratadine (SAR, CIU) or mizolastine (SAR). This agent was significantly more effective, and with a more rapid onset of action, than loratadine in 2-day studies in environmental exposure units (SAR). In paediatric patients, cetirizine was as at least as effective as chlorphenamine (chlorpheniramine) [SAR], loratadine (SAR, PAR) and oxatomide (CIU) in the short term, and more effective than oxatomide and ketotifen (PAR) in the long term. Cetirizine was effective in reducing symptoms of allergic asthma in adults and reduced the relative risk of developing asthma in infants with atopic dermatitis sensitised to grass pollen or house dust mite allergens. It had a corticosteroid-sparing effect in infants with severe atopic dermatitis and was effective in ameliorating reactions to mosquito bites in adults. Cetirizine was well tolerated in adults, adolescents and paediatric patients with allergic disorders. In adult, adolescent and paediatric patients aged 2-11 years, the incidence of somnolence with cetirizine was dose related and was generally similar to that with other second-generation H1 receptor antagonists. Although, its sedative effect was greater than that of fexofenadine in some clinical trials and that of loratadine or fexofenadine in a postmarketing surveillance study. In infants aged 6-24 months, the tolerability profile of cetirizine was similar to that of placebo. Cetirizine did not have any adverse effects on cognitive function in adults, or cognitive function, behaviour or achievement of psychomotor milestones in paediatric patients. Cetirizine was not associated with cardiotoxicity.

CONCLUSION

Cetirizine is well established in the treatment of symptoms of SAR, PAR or CIU. It demonstrated a corticosteroid-sparing effect and reduced the relative risk of developing asthma in sensitised infants with atopic dermatitis. Cetirizine was effective in the treatment of allergic cough and mosquito bites; however, its precise role in these indications has yet to be clearly established. On the basis of its favourable efficacy and tolerability profile and rapid onset of action, cetirizine provides an important option for the treatment of a wide range of allergic disorders.

Stabilization of asthma prevalence among adolescents and increase among schoolchildren (ISAAC phases I and III) in Spain

BACKGROUND

Most studies show a steep increase in asthma prevalence in the last decades, although few studies had applied the same methodology. Recent reports point out the possibility that the epidemic has come to an end. We have studied the prevalence of asthma in a very large sample of children, repeating the study eight years apart.

METHODS

Repeated cross-sectional studies using the International Study of Asthma and Allergies in Childhood (ISAAC) protocol in a sample of Spanish schoolchildren 6-7 (parent-reported) and 13-14 (self-reported) years old in 1994-95 (phase I) and 2002-2003 (phase III). The number of participants was 42 417 in phase I and 42 813 in phase III. The participation rate was over 87% (13-14 years) and 70% (6-7 years).

RESULTS

The prevalence of wheezing in the previous year in children aged 13-14 years was 9.0 and 9.3% for boys and 9.6 and 9.2% for girls for phases I and III, respectively. Children 6-7 years of age showed a substantial increase in wheezing in the previous year (7.0 and 10.7% for boys and 5.3 and 8.2% for girls). Other symptoms and severity indexes followed the same patterns.

CONCLUSIONS

In the last 8 years, the prevalence of asthma has not changed in 13-14-year-old Spanish children but has increased substantially in 6-7-year olds.

Allergic rhinitis and impairment issues in schoolchildren: a consensus report

BACKGROUND

Allergic rhinitis (AR) can have substantial negative impact on children. Most notably, it can impede learning during the school-age years. Other consequences include adverse behavioral and psychosocial effects, poor quality of life, and potential impact on serious comorbidities, such as asthma.

CONSENSUS PANEL

In February 2004, in a conference sponsored by Aventis Pharmaceuticals, a multidisciplinary group convened to review relevant clinical data for the purposes of developing consensus recommendations for the management of AR in children. The consensus panel consisted of academic, school health, and medical providers, who were identified based on previous work and publications.

CONSENSUS FINDS

The focus of discussions was to assess the degree of impact of AR in schoolchildren and, based on this information, to determine how to improve screening, diagnosis, prevention, and treatment, to help ensure quality of life and maximal school performance in this population. The group considered the most critical factor in successful management ot be communication and collaboration among parents, educators, and healthcare professionals. Knowledge of the common signs and symptoms of AR in children can help to ensure early diagnosis, appropriate intervention, and clinically favorable outcomes. Importantly, both uncontrolled symptoms of AR, as well as adverse effects from medications, can diminish cognitive function and learning. When choosing treatment for children with AR, consideration must be given to the side effects of medications. All first-generation and some second-generation antihistamines can be associated with adverse effects on cognitive function and learning, as a result of their sedative properties. Treatment with non-sedating second-generation antihistamine has been shown to improve learning potential and is an ideal choice for treatment in this population.

CONCLUSION

Existing data indicate that further studies using objective measures of impairment in children taking antihistamine medications should be conducted to evaluate the impact of disease and treatment.

Patient preferences for sensory attributes of intranasal corticosteroids and willingness to adhere to prescribed therapy for allergic rhinitis: a conjoint analysis

BACKGROUND

Sensory attributes of intranasal corticosteroid (INS) products vary.

OBJECTIVE

To evaluate patient preferences for INS sensory attributes and the degree to which attributes influence patients' willingness to adhere to therapy.

METHODS

We conducted a cross-sectional study with 120 individuals across 4 US allergy/immunology clinics. Respondents chose between pairs of hypothetical INSs differing in sensory attribute composition. We measured the strength of preferences for 6 sensory attributes (smell, taste, aftertaste, throat rundown, nose runout, and feel of spray in nose or throat). Preferences were measured for 3 intensity levels of each sensory attribute (eg, no taste, weak taste, and strong taste). Other outcomes included an importance score for each sensory attribute and patients' willingness to adhere to therapy with an INS with the lowest intensity levels of each sensory attribute vs one with moderate intensity levels.

RESULTS

Preferences decreased with increasing intensity levels of each sensory attribute. Aftertaste was the most important attribute in 28% of patients, taste in 19%, throat rundown in 18%, nose runout in 12%, smell in 11%, and feel of spray in 7%. If instructed to take an INS daily for 3 months, 77% of patients stated that they would definitely be able to follow their physician's advice (willingness to adhere) if given one containing the lowest level of each sensory attribute vs 4% if given one having moderate levels (P < .01).

CONCLUSIONS

Patient preferences are inversely related to increasing intensity levels of sensory attributes and affect patients' willingness to adhere to therapy. Application of patient preferences when selecting INSs could improve adherence.

Infections, medication use, and the prevalence of symptoms of asthma, rhinitis, and eczema in childhood

BACKGROUND

The "hygiene hypothesis" postulates that infections during infancy may protect against asthma and atopy. There is also some evidence that antibiotic and/or paracetamol use may increase the risk of asthma.

METHODS

The study measured the association between infections, and medication use early in life and the risk of asthma at age 6-7 years. It involved 1584 children who had been notified to public health services with serious infections at age 0-4 years, and 2539 children sampled from the general population. For both groups, postal questionnaires were completed by parents.

RESULTS

There was little difference in the prevalence of current wheezing between the childhood infections group (prevalence = 23.5%) and the general population group (prevalence = 24.3%). There was also little difference whether the major site of infection was gastrointestinal (prevalence = 24.1%), invasive (prevalence = 24.6%) or respiratory (prevalence = 21.1%). However, in both groups, there were associations with antibiotic (OR = 1.78, 95% CI 1.49 to 2.14) or paracetamol (OR = 1.38, 95% CI 1.04 to 1.83) use in the first year of life or recent paracetamol use (OR = 2.10, 95% CI 1.78 to 2.49) and current wheezing. There was a weak protective effect of childhood infections in children who had not used antibiotics in the first year of life (OR = 0.78, 95% CI 0.55 to 1.10).

CONCLUSIONS

These findings are consistent with other evidence that antibiotic use early in life may increase the risk of asthma. They are also consistent with some preliminary evidence associating paracetamol use with an increased risk of asthma. Any protective effect of notifiable childhood infections was weak.

Efficacy and comfort of olopatadine versus ketotifen ophthalmic solutions: a double-masked, environmental study of patient preference

BACKGROUND

Ocular allergies cause itching, redness, chemosis, tearing, and swelling of the eyelids in sensitized individuals. The options available for treatment of ocular allergy include olopatadine 0.1% (Opatanol; Patanol [US]) and ketotifen 0.025% (Zaditen; Zaditor [US]). Patient preference for an eye drop can often be a primary factor in determining the level of compliance and satisfaction with any given therapy.

OBJECTIVE

This study sought patient perspective on eye drop efficacy in controlling signs and symptoms of allergic conjunctivitis and eye drop comfort. Also evaluated were the factors considered by patients when making decisions of preference.

METHODS

One hundred patients with previous history and current symptoms of seasonal or perennial allergic conjunctivitis were enrolled at two centers (Athens, Greece, N = 50; Padova, Italy, N = 50) for this two visit, double-masked study. Qualified patients received two masked bottles of medication (one olopatadine, one ketotifen) and were asked to use both medications as needed over the course of four weeks, but not to exceed usage of two drops of medication per eye per day. At the second visit, patients answered five questions comparing the two masked medications in terms of preference, drop comfort, and efficacy in treatment of signs and symptoms. Patients also defined the factors upon which they based these decisions.

RESULTS

A significantly greater percentage of patients (81%) selected olopatadine when asked which medication they preferred; which they found more comfortable; which they found more efficacious in reducing symptoms of allergy; and which they would select if visiting the doctor's office (P < 0.0001). Seventy-six percent (76%) of patients considered both efficacy and comfort when making their preference decisions (P < 0.0001). No adverse events were volunteered or elicited.

CONCLUSION

In this study, patients preferred to use the anti-allergy eye drop olopatadine over ketotifen after using both drops and evaluating relative efficacy and comfort during the course of four weeks. A significantly greater percentage of the patients preferred to use olopatadine during the study period, found it more efficacious and comfortable, and would select olopatadine if visiting their doctor's office during allergy season.

Self-reported traffic density and atopic disease in children. Results of the ISAAC Phase III survey in Muenster, Germany

Positive associations between traffic exposure and atopic respiratory disorders in children have been described in several studies. We analyzed data related to self-reported truck traffic density and several symptoms and diagnoses of asthma and hay fever (12-month wheezing and rhinitis symptoms, diagnoses of asthma and hay fever) from the ISAAC Phase III survey in Muenster, Germany, using core written and video questionnaires. Data were collected from representative school-based samples (n = 7345) of 6-7- and 13-14-yr-olds. In 13-14-yr-olds, according to exposure levels categorized into rare, frequent, and constant, with the 'never'-category used as reference, the sex-adjusted prevalence ratios were 1.29 (95% CI = 1.08-1.53), 1.58 (1.29-1.94), and 1.57 (1.18-2.10) for wheeze in the past 12 months, and 1.20 (1.06-1.34), 1.35 (1.17-1.55), and 1.69 (1.42-2.0) for rhinitis symptoms in the past 12 months. Prevalence ratios in 6-7-yr-olds and results for a diagnosis of asthma were less consistent while no positive association was detected between hay fever and truck traffic in both age groups. When analyses were based on a more general traffic indicator (self-reported traffic noise), no consistent associations were observed. Our data provide support for the hypothesis that residential exposure to truck traffic may adversely affect the health of children.

Climate and the prevalence of symptoms of asthma, allergic rhinitis, and atopic eczema in children

AIMS

To investigate the association between climate and atopic diseases using worldwide data from 146 centres of the International Study of Asthma and Allergies in Childhood (ISAAC).

METHODS

Between 1992 and 1996, each centre studied random samples of children aged 13-14 and 6-7 years (approx. 3000 per age group and centre) using standardised written and video questionnaires on symptoms of asthma, allergic rhinoconjunctivitis, and atopic eczema during the past 12 months. Data on long term climatic conditions in the centres were abstracted from one standardised source, and mixed linear regression models calculated to take the clustering of centres within countries into account.

RESULTS

In Western Europe (57 centres in 12 countries), the prevalence of asthma symptoms, assessed by written questionnaire, increased by 2.7% (95% CI 1.0% to 4.5%) with an increase in the estimated annual mean of indoor relative humidity of 10%. Similar associations were seen for the video questionnaire and the younger age group. Altitude and the annual variation of temperature and relative humidity outdoors were negatively associated with asthma symptoms. The prevalence of eczema symptoms correlated with latitude (positively) and mean annual outdoor temperature (negatively).

CONCLUSIONS

Results suggest that climate may affect the prevalence of asthma and atopic eczema in children.

Socioeconomic status and prevalence of allergic rhinitis and atopic eczema symptoms in young adolescents

Environmental factors are known to influence the development of allergic rhinitis and atopic eczema in genetically susceptible individuals. Socioeconomic status (SES) may be an important indicator of risk for these conditions. The International Study of Asthma and Allergies in Childhood (ISAAC) Phase 1 written questionnaire was used to determine the prevalence and severity of allergic rhinoconjunctivitis and atopic eczema symptoms in 4947 pupils aged 13-14 years attending 30 schools in socioeconomically diverse areas of Cape Town. Home addresses were used to stratify participants into five SES bands. Relationships between symptom prevalence and severity, and SES, recent urbanization and upward socioeconomic mobility were examined. Logistic regression was used to generate odds ratios (OR) and 95% confidence intervals (CI) in order to assess overall trends by SES. The prevalences of self-reported allergic rhinitis symptoms and recurrent itchy rash in the past year were 33.2% and 11.9% respectively. Girls had a significantly higher prevalence of all symptoms than boys. The prevalence of allergic rhinitis symptoms increased from lowest to highest SES (overall OR for rhinitis symptoms in past year = 1.16, 95% CI 1.11-1.21). There was no significant trend in reported eczema symptoms by SES other than for the question, 'Have you ever had eczema' (OR = 0.88, 95% CI 0.83-0.93). Longer period of urbanization was weakly associated only with recurrent itchy skin rash (OR = 1.05, 95% CI 1.01-1.09). 'Socially mobile' pupils, i.e. those resident in the lowest SES areas but attending highest SES schools showed significantly higher prevalences of eczema and some rhinitis symptoms than pupils attending lowest SES schools. These findings may reflect differences in reporting related to language, culture and access to medical care rather than real differences in prevalence.

Genetics, epigenetics, and the environment: switching, buffering, releasing

Increasing evidence suggests that the interactions between genes and environment might play a critical role in the pathogenesis of complex diseases, such as asthma, that exhibit a heritable component but do not follow Mendel's laws. Gene-environment interactions are extremely complex and not linear, such that the same genetic variants might be associated with opposite phenotypes in different environments. This is particularly evident for innate immunity genes, which operate at the interface between the immune system and the pathogen world. This article examines gene-environment interactions by using CD14 as a model and argues that the conflicting results of epidemiologic studies on CD14*C-159T result from differences in environmental conditions essential to modulate CD14 gene expression. Furthermore, on the basis of how rapidly environmental changes have affected the incidence of immune diseases, I argue that a full understanding of gene-environment interactions requires that epigenetic as well as classical genetic mechanisms be taken into account. Recent data about the effect of diet on gene methylation and the release of hidden genetic variation by impairment of heat shock protein 90-mediated buffering systems offer eloquent examples of how epigenetic mechanisms might affect gene-environment interactions.

Prevalence of rhinitis and related-symptoms in schoolchildren from different cities in Brazil

By using the standard written questionnaire (WQ), designed for the International Study of Asthma and Allergies in Childhood (ISAAC) we determined the prevalence of rhinitis and its related-symptoms, in Brazilian children and adolescents, living in different cities of the country. The WQ was answered by the parents of 11,403 children aged 6-7 years from five Brazilian cities: Porto Alegre (South, N = 2,846), São Paulo (Southeast, N = 3,005) Uberlândia (Southeast, N = 2,991), Itabira (Southeast, N = 1,151) and Recife (Northeast, N = 1,410). The WQ was also applied to 20,587 adolescents (13-14 years old) living in: Porto Alegre (South, N = 3,195), Curitiba (South, N = 3,004), São Paulo (Southeast, N = 3,008), Uberlândia (Southeast, N = 2,998), Itabira (Southeast, N = 2,134), Salvador (Northeast, N = 3,162) and Recife (Northeast, N = 3,086). The mean response rates were 75% and 95%, for the 6-7 year-old children and for the adolescents, respectively. The data was transcribed to a database (Epi-Info) and analyzed regarding the answers to questions of rhinitis module. The mean prevalence of rhinitis (affirmative response to question 2) was 26.6% and 34.2% in the groups of 6-7 and 13-14 year-old, respectively. Applying the criteria that evaluate the association between nasal and ocular symptoms (affirmative response to question 3) the mean prevalence of allergic rhinitis were 12.8% for the 6-7 year-old children and 18.0% for the adolescents. In conclusion, the prevalence of rhinitis and its related symptoms among children and adolescents living in different Brazilian cities was as high as the prevalence observed in other areas of the world.

The effect of BCG vaccine at birth on the development of atopy or allergic disease in young children

BACKGROUND

Exposure to infectious diseases may reduce the development of asthma or allergy. In particular, the role of the BCG vaccine in modulating asthma or allergy has been a source of speculation.

OBJECTIVE

To study newborns from 3 international sites to evaluate the prospective effect of BCG vaccine on allergic diseases or atopic development.

METHODS

Infants were enrolled from newborn and well-infant clinics in Thailand, Argentina, and Turkey. The standard BCG vaccine for each country was given at birth. Parents who consented to have their infant included in the protocol completed an allergy family questionnaire. Infants underwent a standard purified protein derivative (PPD) test at 9 to 12 months of age, and the reaction size was measured. At the age of 2 years, the children returned to be studied. Allergy skin tests to common allergens appropriate to location and age were performed, and the parents completed the International Study of Allergy and Asthma in Childhood questionnaire. The PPD reaction size was compared with the presence of atopy and allergy questionnaire responses.

RESULTS

A total of 1,704 infants were studied. Statistical significance was found between a negative PPD response vs any positive PPD response and the risk of having an allergic history at the age of 2 years in Turkey (relative risk, 2.11; 95% confidence interval, 1.25-3.55; P = .005) and Thailand (relative risk, 2.16; 95% confidence interval, 1.18-3.94; P = .02) but not Argentina (relative risk, 1.09; 95% confidence interval, 0.70-1.68; P = .70).

CONCLUSIONS

This study further supports the role of infectious agents in modulating asthma and allergy development.

Montelukast for treating fall allergic rhinitis: effect of pollen exposure in 3 studies

BACKGROUND

Montelukast, a potent leukotriene receptor antagonist, is an effective therapy for symptoms of seasonal allergic rhinitis, a disease governed by patients' individual sensitivity and exposure to relevant allergens.

OBJECTIVE

To evaluate the relationship of montelukast treatment effect vs pollen exposure in studies conducted during 3 consecutive fall allergy seasons.

METHOD

A combined analysis of these multicenter, randomized, double-blind, parallel-group studies was performed; 1 of the 3 studies is presented for the first time in this article. After a placebo run-in period, 1,862 symptomatic patients were randomly assigned to receive either a 10-mg montelukast tablet (n = 929) or placebo (n = 933) once daily for 2 weeks. Pollen exposure was summarized by mean daily weed pollen count. The interaction between treatment effect and pollen exposure was evaluated on the primary efficacy endpoint and daytime nasal symptom score, as rated by patients; also evaluated was the influence of the timing of the 2-week treatment period relative to the peak of the weed pollen season.

RESULTS

Montelukast significantly improved daytime nasal symptoms score and individual scores of congestion, rhinorrhea, itching, and sneezing compared with placebo. There was a significant interaction (P < .043) between treatment effect and weed pollen exposure; a larger treatment effect was noted in patients exposed to higher pollen counts. An interaction between treatment effect and timing of treatment in relation to peak pollen season was suggested.

CONCLUSIONS

Montelukast significantly improved daytime nasal symptoms score in patients with seasonal allergic rhinitis, and the effect was greater in patients exposed to higher pollen levels.

Therapeutic strategies for allergic airways diseases

Asthma and allergic rhinitis are airways allergic diseases and different aspects of these diseases are discussed in this paper. Both diseases require specific treatment but the airways are a continuum and it has been shown that concomitant treatment in patients suffering from both diseases has a better effect than treating only one of the diseases. Furthermore, treatment of allergic rhinitis in asthmatic patients reduces the risk of hospital admission due to asthma and improves bronchial hyper-responsiveness. Anti-inflammatory therapy, particularly with local steroids, is the single most important treatment for airways allergic diseases. Some studies have shown the importance of starting early after diagnosing asthma but the issue of how early in life to start inhaled steroids is still being debated. Also leukotriene antagonists have been shown to have beneficial effects in many patients and can be used in conjunction with inhaled steroids. Combination therapy with inhaled steroids and inhaled beta(2)-agonists has been shown to be effective in adults but this has not yet been fully documented in children. Optimal treatment of exercise-induced asthma is important to enable children and adolescents to fulfill their developmental possibilities. Allergy vaccination has traditionally been used for treating airways allergic diseases. It is often given for allergic rhinitis when pharmacotherapy is not providing full symptom control. One recent study has suggested that allergy vaccination may possibly help to prevent the development of asthma in the child with allergic rhinitis. More research is needed on asthma allergy vaccination. Concordance with treatment may often be difficult and efforts should be taken to ensure the best concordance possible.

Safety and tolerability profiles of intranasal antihistamines and intranasal corticosteroids in the treatment of allergic rhinitis

Intranasal corticosteroids and intranasal antihistamines are efficacious topical therapies in the treatment of allergic rhinitis. This review addresses their relative roles in the management of this disease, focusing on their safety and tolerability profiles. The intranasal route of administration delivers drug directly to the target organ, thereby minimising the potential for the systemic adverse effects that may be evident with oral therapy. Furthermore, the topical route of delivery enables the use of lower doses of medication. Such therapies, predominantly available as aqueous formulations following the ban of chlorofluorocarbon propellants, have minimal local adverse effects. Intranasal application of therapy can induce sneezing in the hyper-reactive nose, and transient local irritation has been described with certain formulations. Intranasal administration of corticosteroids is associated with minor nose bleeding in a small proportion of recipients. This effect has been attributed to the vasoconstrictor activity of the corticosteroid molecules, and is considered to account for the very rare occurrence of nasal septal perforation. Nasal biopsy studies do not show any detrimental structural effects within the nasal mucosa with long-term administration of intranasal corticosteroids. Much attention has focused on the systemic safety of intranasal application. When administered at standard recommended therapeutic dosage, the intranasal antihistamines do not cause significant sedation or impairment of psychomotor function, effects that would be evident when these agents are administered orally at a therapeutically relevant dosage. The systemic bioavailability of intranasal corticosteroids varies from <1% to up to 40-50% and influences the risk of systemic adverse effects. Because the dose delivered topically is small, this is not a major consideration, and extensive studies have not identified significant effects on the hypothalamic-pituitary-adrenal axis with continued treatment. A small effect on growth has been reported in one study in children receiving a standard dosage over 1 year, however. This has not been found in prospective studies with the intranasal corticosteroids that have low systemic bioavailability and therefore the judicious choice of intranasal formulation, particularly if there is concurrent corticosteroid inhalation for asthma, is prudent. There is no evidence that such considerations are relevant to shorter-term use, such as in intermittent or seasonal disease. Intranasal therapy, which represents a major mode of drug delivery in allergic rhinitis, thus has a very favourable benefit/risk ratio and is the preferred route of administration for corticosteroids in the treatment of this disease, as well as an important option for antihistaminic therapy, particularly if rapid symptom relief is required.

Comparative clinical efficacy, onset and duration of action of levocetirizine and desloratadine for symptoms of seasonal allergic rhinitis in subjects evaluated in the Environmental Exposure Unit (EEU)

The Environmental Exposure Unit, an indoor pollen challenge system to test anti-allergic medications, was used to compare the onset and duration of action and the efficacy of levocetirizine and desloratadine, two recently developed H1-antagonists. In this double-blind, placebo-controlled, parallel-group study, qualified subjects were randomised to once-daily levocetirizine 5 mg (n = 141), desloratadine 5 mg (n = 140) or placebo (n = 92) and exposed to ragweed pollen on two consecutive days (7 h and 6 h). Symptoms were self-rated every 30 min. On both days, levocetirizine produced a greater improvement in the major symptom complex score (primary efficacy variable) than desloratadine (p = 0.015); both were better than placebo (p < 0.001). Levocetirizine acted earlier (1 h vs. 3 h) and produced greater symptom relief at 24 h than desloratadine (p = 0.003). Levocetirizine also alleviated nasal obstruction better than desloratadine (p = 0.007) on day 1; and better than placebo (p = 0.014) after the second dose on day 2, which was not observed with desloratadine. Levocetirizine and desloratadine were safe and well tolerated.

Increasing prevalence of allergic rhinitis but not asthma among children in Hong Kong from 1995 to 2001 (Phase 3 International Study of Asthma and Allergies in Childhood)

There is a worldwide belief that the prevalence of asthma and other allergic diseases is increasing but the measures used in many studies are susceptible to systematic errors. We examined the trend of asthma, allergic rhinitis and eczema prevalence in school children aged 6-7 years in Hong Kong from 1995 to 2001 using standardized ISAAC methodology. There were 4448 and 3618 children participating in 2001 and 1995, respectively. The prevalence of life-time rhinitis (42.4% vs. 38.9%, p < 0.01), current rhinitis (37.4% vs. 35.1%, p < 0.03), current rhinoconjunctivitis (17.2 vs. 13.6%, p < 0.01) and life-time eczema (30.7% vs. 28.1%, p = 0.01) increased significantly. There was no significant change in prevalence of life-time asthma, life-time wheeze and current wheeze albeit a significant increase in severe asthma symptoms. We investigated a number of potential risk factors including sex, family history of atopy, sibship size, birth weight, respiratory tract infections, pet ownership and exposure to tobacco smoke. However, the increases in prevalence of rhinitis and eczema could not be entirely explained by the change of prevalence of these risk factors. The odds ratio OR for the study period remained significantly associated with current rhinitis (OR 1.31, 95% confidence intervals CI 1.17-1.46), current rhinoconjunctivitis (OR 1.63, 95% CI 1.41-1.87) and life-time eczema (OR 1.30, 95% CI 1.16-1.45) after adjustment for these confounding variables using logistic regression model. Further study is warranted to elucidate the factors contributing to the observable change in the prevalence of rhinitis in our population.

Is there a causative role for tetanus toxoid vaccination in the development of allergy-like symptoms and in the increasing prevalence of atopic diseases?

Allergic diseases are a worldwide health problem. They mainly affect people living in developed countries where an increasing prevalence of allergy symptoms has been recorded in the last 20-30 years. The cause of this increase is still disputed, and, among others, the "hygiene hypothesis" supported the concept that relevant changes in lifestyle could have a relationship with the phenomenon. More recently the recorded parallel increase in autoimmune diseases has suggested to consider the "hygiene hypothesis" as a cause of a more general disregulation of the immune system leading to both allergy and to autoimmunity. Here are reported a series of observations, evidence, and data from the literature leading to a different hypothesis. The key points are: (1) the presence of two subsets of patients having allergy symptoms based on an IgE-mediated mechanism or not; (2) the positive results obtained with the autologous serum skin test in either cutaneous or respiratory affected subjects, mainly in children and adult females; (3) the presence of IgG autoantibodies against the alpha-chain of the high affinity IgE receptor (FcepsilonRIalpha) in non-IgE-mediated urticaria and even in respiratory subjects; (4) the cross-reactivity between epitopes of the tetanus toxoid molecule and the FcepsilonRIalpha detected by means of an alpha-chain affinity purified IgG fraction; (5) the positive skin reactivity obtained using IgG anti-tetanus toxoid preparations in allergic and non-allergic volunteers. The presence of IgG autoantibodies actively generated by the population-based vaccination with tetanus toxoid could induce both mediator release from activated mast cell and Th2 cytokine production early in life. There are epidemiological evidences that tetanus toxoid vaccination could be linked with an increased tendency to have allergy symptoms. The different epidemiological distribution of non-IgE-mediated symptoms, mainly affecting young infants would be in agreement with the present hypothesis. The prevalent mother-to-child relationship in terms of risk for allergy symptoms could be explained with the trans-placenta transfer of IgG. A similar transfer could also take place through the mother milk during breast feeding. It may thus be hypothesized that the increased prevalence of allergic diseases could be caused by the generalized tetanus toxoid immunization procedure, progressively extended to most of the countries worldwide in the last 30-40 years. Both the induction of non-IgE-mediated symptoms caused by the mast cell activation via the anti-FcepsilonRIalpha IgG and the long lasting Th2 inflammation of affected tissues would be the inducing mechanisms. This hypothesis would re-configure part of the allergic diseases as a Th2 phenotypic expression of an autoimmune disease.

Clinical and therapeutic aspects of allergic asthma in adolescents

Little is known about the management of asthma in adolescents. We aimed at evaluating these aspects, through a specific questionnaire, in the real life of adolescents with allergic asthma. The questionnaire was administered to a group of adolescents after a diagnosis of allergic asthma. The diagnosis was based on history, clinical examination, pulmonary function tests and allergy tests. One hundred and fifteen adolescents (65 males, mean age 16.5 years) fulfilled the criteria for allergic asthma. The questionnaire explored demography, family history, clinical history, previous diagnosis, therapy, attitude towards therapy and social aspects. The mean actual FEV1 was 87 +/- 10%. Methacholine challenge was carried out in 79 patients and was always positive (PD20 < 1,200 microg), whereas 36 patients underwent reversibility test. According to GINA guidelines, severity of asthma resulted intermittent in 62, mild persistent in 31, moderate in 19 and severe in three patients. In 61% of cases teachers were not aware of the disease. Asthma was managed by general practitioners, allergists and pulmonologists, but PFT/allergy tests had never been performed in 14% of patients. Forty-two per cent of the adolescents received no therapy at all, and only 15% of those with persistent asthma were receiving a stable treatment. Seventy-four per cent of adolescents preferred the inhaled, as against the oral, route. From a clinical and functional point of view, asthma in adolescents did not differ from other age ranges. Nevertheless, the management (diagnosis and therapy) emerged to be unsatisfactory from many points of view.

Effects of triamcinolone on quality of life in patients with persistent allergic rhinitis

OBJECTIVE

To study the effects of triamcinolone acetonide on health-related quality of life (HRQL) in adult patients with allergic rhinitis.

METHODS

This study was conducted in South Africa as a placebo-controlled, multicenter, randomized, double-blind study. Following a 7-day baseline run-in, patients were treated for 28 days with either triamcinolone or placebo. Interviewer-assisted quality-of-life assessments were conducted using the Juniper Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ). Total symptom scores, including nasal congestion, were measured using daily diary cards.

RESULTS

A total of 337 patients were recruited and 253 patients completed the study per protocol, of which 55 had seasonal allergic rhinitis (SAR) and 198 had persistent allergic rhinitis (PAR). Improvements in the mean scores per area of the RQLQ were significantly better with triamcinolone compared with placebo for the entire study group for activities (P = .04 at visit 4) and sleep, nasal symptoms, emotional problems, and overall score (P = .002, P = .04, P = .03, and P = .04, respectively, at visit 3). When the patients with SAR were separated from the patients with PAR in the analysis, improvement with triamcinolone was better than placebo only in the PAR patients. The overall investigator and patient assessments of relief favored triamcinolone.

CONCLUSIONS

Triamcinolone given for 4 weeks improves symptom scores and HRQL in patients with allergic rhinitis. The ability of triamcinolone to relieve nasal congestion symptoms in PAR patients was correlated with improvements in HRQL.

ISAAC-based asthma and atopic symptoms among Ha Noi school children

Childhood asthma and atopy prevalence patterns in the developing world are only beginning to be defined. No such information exists for Vietnam. Estimates would assist in anticipating health service needs as well as add to the growing database on global patterns of atopy. To estimate the prevalence of atopic symptoms in school children in Ha Noi, Vietnam, a cross-sectional survey was conducted of children aged 5- to 11-years-old in two schools using the parent self-administered International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. The response rate was 66.4% (969 responses). The overall prevalence of selected symptoms were: 'ever wheezed' 24.9%, 'wheezed in past 12 months' 14.9%, 'ever had asthma' 12.1%, 'doctor-diagnosed asthma' 13.9%, 'ever experienced allergic rhinitis (AR) symptoms' 34.9%, 'AR-conjunctivitis symptoms in past 12 months' 10.7%, 'ever had hay fever' 7.8%, 'doctor-diagnosed hay fever' 11.2%, 'ever had eczema' 3.3% and 'doctor-diagnosed eczema' 3.2%. Kappa statistics demonstrated high within symptom category consistency for 'ever had asthma/doctor-diagnosed asthma' (0.728) and 'ever had eczema/doctor-diagnosed eczema' (0.906). Age and gender adjusted odds ratios (OR) were also consistently significant across wheeze and allergic rhinitis symptom categories [highest OR = 10.10 (95% CI 6.23-16.35) between allergic rhinoconjunctivitis and wheeze in past 12 months]. There is a high prevalence of ISAAC-based symptoms in school children in Ha Noi, Vietnam, often above global averages. The high level of association between atopic symptoms suggests some degree of reliability and validity. Childhood atopy symptom prevalence in Vietnam is more similar to that in developed countries rather than developing countries.

General strategy for the management of bronchial asthma in pregnancy

Epidemiological studies showed that bronchial asthma is one of the most common diseases which can complicate pregnancy (1-7%). In about 0.05-2% of the cases, asthma occurs as a life-threatening event. In the common medical practice a waiting strategy or, even, the complete refusal for drug therapies are frequently observed. This is justified by the fear of the possible adverse effects of drugs on developing fetus. On the contrary, several studies have demonstrated that severe and uncontrolled asthma may produce serious maternal and fetal complications, such as gestational hypertension and eclampsia, fetal hypoxemia and an increased risk of perinatal death. Therefore, all pregnant women suffering from bronchial asthma should be considered as potentially at high risk of complications and adequately treated. Since asthma is a chronic disease with acute exacerbations, a continuous treatment is mandatory to control symptoms, to prevent acute episodes and to reduce the degree of airway inflammation. The global strategy for asthma management in pregnancy includes five main topics: (1) objective evaluation of maternal/ fetal clinical conditions; (2) avoidance/control of triggering factors; (3) pharmacological treatment; (4) educational support; (5) psychological support. As far as drug therapy is concerned, the International Guidelines and Recommendations suggest that the general strategy does not differ significantly from management outside pregnancy. We herein review and discuss the available data and the criteria for the management of asthma in pregnant patients.

Are asthma and allergies in children and adolescents increasing? Results from ISAAC phase I and phase III surveys in Münster, Germany

OBJECTIVE

To assess time trends in symptoms of asthma, allergic rhinitis, and atopic eczema among children in Münster, Germany.

METHODS

Two cross-sectional surveys 5-years apart (1994/1995, 1999/2000) using ISAAC core written and video questionnaires and applying the ISAAC protocol. Two main age groups (6-7 and 13-14 year olds) were designated with information collected by parental and self-report for both age groups, respectively. A school-based sample of 7744 participants in the 1994/1995 survey and 7962 participants in the 1999/2000 survey was recruited. In the first and second surveys, response rates for the 6-7 year olds were 81 and 82%, respectively, while for the 13-14 year olds response rates were 94% in both. Analyses focus on the change in 12-month prevalence of symptoms of asthma, rhinitis, and eczema.

RESULTS

There is a tendency towards an increase in current symptoms for all three conditions and in both age groups, but more so among girls. Indices of diagnosis either remained the same or increased in parallel to the increase in symptoms. Indices of severity also showed a homogenous increase in the 5-year study period.

CONCLUSIONS

Our study shows that symptoms of asthma, rhinitis, and eczema are increasing, reflecting a change in the morbidity of these conditions in our population.

Prevalence of symptoms of asthma and allergies in schoolchildren in Gondar town and its vicinity, northwest Ethiopia

A low level of allergic disorders has been generally reported in children from developing countries. A survey was conducted to determine the prevalence of symptoms of asthma and allergies among schoolchildren in Gondar, northwest Ethiopia. A standardized self-administered questionnaire developed by the International Study of Asthma and Allergies in Children (ISAAC) was used. In total, 3,365 children aged 13-14 years were surveyed at school, with a response rate of 98.4%. The female to male ratio was 1.5:1. The 12-month-period prevalences of wheeze (16.2%), rhino-conjunctivitis (14.5%), and eczema (10.9%) were comparable to findings from Addis Ababa, but significantly higher than reported from Jimma. A striking seasonal pattern of rhinitis symptoms is observed during the months of September-December with a peak in November, corresponding with the main pollen season of the area. Overall, about 36% of the children reported symptoms of atopic disorders. However, the prevalence of diagnosed atopic diseases (8.6%) is less than a quarter of the symptom prevalence rate. This may reflect a generally poor awareness and low health service utilization, or underdiagnosis by health facilities. In conclusion, it appears that the prevalence of atopic diseases in Gondar area is high, and there is also wide variation within the country. This calls for further epidemiological studies with more objective assessments of atopy, such as allergen and bronchial hyperresponsiveness tests and ecological analysis.

Development and validation of school-based asthma and allergy screening instruments for parents and students

BACKGROUND

The increasing morbidity attributable to asthma among school-aged children suggests the potential utility of school-based asthma screening programs.

OBJECTIVE

We report our efforts to develop and validate culturally sensitive and clinically useful screening questionnaires (parent and child versions) for asthma and allergies among urban US school children.

METHODS

Instrument development was accomplished through literature review, expert medical and child developmental input, focus group feedback, and a rigorous trial of the instruments in a public school setting. Questionnaires were distributed to 2,800 children and their families in an urban public school system (grades kindergarten through 6). Validity was evaluated by blinded comparison of results against a standardized clinical evaluation in 107 children, with final designations determined by an expert panel.

RESULTS

Questionnaires pertaining to 2,083 children were returned (participation rate of 74%). A moderate level of agreement was observed between parent and student questionnaire responses (r values = 0.36 to 0.50; P values < 0.001). The highest frequency of asthma-like symptoms was reported for African-American boys and the lowest for Caucasian girls. The items from the parent questionnaire that best predicted asthma were "breathing problems" (occurring rarely or more; odds ratio 12.8; 95% confidence interval, 4.5 to 36.1) and "problems coughing" (sometimes or more; odds ratio 9.7; 95% confidence interval, 3.6 to 26.5). Considering the presence of cough (sometimes or more) and/or breathing problem (rarely or more) yielded a sensitivity of 80%; a specificity of 75%, a positive predictive value of 50%, and a negative predictive value of 92%. Similar levels of prediction were observed for the items "trouble breathing" and "noisy breathing" as directly reported by the students. Allergic rhinitis was best predicted by report of a runny/stuffy no se (sometimes or more; sensitivity of 83%, specificity of 61%). Allergic conjunctivitis was best predicted by "itchy eyes."

CONCLUSIONS

Administration of a school-based questionnaire is feasible, with a high response rate and excellent internal consistency. A high sensitivity and acceptable specificity was achieved by using one to two questions for asthma, allergic rhinitis, and allergic conjunctivitis. Among the children in grades 2 or above, comparable levels of prediction could be achieved with the student or parent version.

Therapeutic points of intervention and clinical implications: role of desloratadine

Desloratadine, a potent, once-daily, orally active, nonsedating, histamine H1-receptor antagonist, inhibits the release of histamine and other inflammatory mediators. Once-daily desloratadine therapy rapidly reduces the symptoms of perennial allergic rhinitis and seasonal allergic rhinitis (SAR), reduces the use of inhaled albuterol by patients with SAR and concomitant asthma, and improves symptoms and quality of life in patients with chronic idiopathic urticaria. An open-label, observational study in SAR patients revealed that desloratadine therapy significantly reduced nasal, ocular, dermal, asthma, and total symptoms, and enabled half of the patients with concomitant asthma to reduce their use of asthma medications. Globally, more than 91% of patients and physicians judged desloratadine to have excellent or good efficacy, and more than 98% judged it to have excellent or good tolerability. Furthermore, desloratadine therapy improved quality of life, decreasing by more than 10-fold the percentage of patients whose daily activities and/or sleep were moderately or severely affected by SAR. Allergic rhinitis, a major chronic airway disease that is a risk factor for asthma, warrants extended diagnostic procedures and well-tolerated therapy that encompasses the entire airway, addresses multiple steps in the allergic inflammatory cascade, and is effective on nasal, ocular, dermal, asthma, and total symptoms.

Introduction to nasal and pulmonary allergy cascade

The early phase of an IgE-dependent allergic reaction is followed by the activation of a complex network of inflammatory phenomena - T lymphocytes, cytokines, mediators, and adhesion molecules - that mediate late and ongoing allergic symptoms. The kinetics of respiratory inflammation following allergen exposure involve the migration of inflammatory cells to the mucosa within about 30 min, increased inflammatory infiltration over the following hours, and then slow subsidence. A relationship between asthma and allergic rhinitis is supported by epidemiological, histological, physiological, and immunopathological data, and by the response of asthma symptoms in rhinitic patients to intranasal corticosteroids and antihistamines. For example, there is no morphological difference between the bronchial inflammatory response following allergen-specific challenge in patients suffering from asthma alone or rhinitis alone. It is the allergen dose that makes the difference in the airway response to allergen in allergic rhinitis and asthma. Recognition of the relationship between asthma and allergic rhinitis has led to the introduction of new diagnostic terminology and treatment recommendations: 1) patients with persistent rhinitis should be evaluated for asthma; 2) patients with persistent asthma should be evaluated for rhinitis; and 3) a strategy should combine the treatment of upper and lower airways in terms of efficacy and safety.

Advances in allergy management

Our understanding of the pathophysiology of allergy has moved to the molecular level, while study of epidemiology and genetics has revealed risks of developing allergies based on environmental and genetic profiles, and pharmacoeconomic data have enabled accurate measurement of the immense burden of allergic disease. These advances in allergy research have affected its management, particularly the search for new antiallergy therapies. New therapies should intervene in the systemic allergy inflammatory cascade and provide clinical efficacy that extends to multiple allergic disease states. In addition, these new therapies should present no additional safety issues, offer improvements over existing therapies, and have an impact on disease-impaired quality of life. In vitro studies show that desloratadine, a new, once-daily, nonsedating, selective histamine H1-receptor antagonist, blocks the systemic allergy cascade at multiple points. Desloratadine 5 mg once daily relieves the symptoms of chronic idiopathic urticaria and of both seasonal (SAR) and perennial allergic rhinitis. In patients with concomitant asthma and SAR, asthma symptoms are relieved and beta2-agonist medication use is decreased by desloratadine. Unlike many other second-generation histamine H1-receptor antagonists, desloratadine provides the added benefit of efficacy against nasal obstruction in SAR. Desloratadine improves quality of life by decreasing the impact of allergic symptoms on sleep and on daily activities.

Hay fever and predictive value of prick test and specific IgE antibodies: a prospective study in children

Little is known from population-based studies in children about the diagnostic values of allergen-specific IgE antibodies (RAST) and skin prick test (SPT) with respect to hay fever. We aimed to determine and compare the diagnostic values of SPT and RAST to aeroallergens with respect to the incidence of hay fever cases in schoolchildren at different cut-off points. A prospective cohort study was performed on 1100 school children (5-7 and 8-10 years). Information on a doctor's diagnosis of hay fever was obtained by questionnaire and allergic sensitization to grass and birch pollen, cat, and Dermatophagoides pteronyssinus were measured using SPT and RAST between September 1992 and July 1993. Thirty-eight children give a history of hay fever (3.5%) in 1992/93 and additionally 37 cases occurred until 1996. Allergic sensitization was present in 17.9% (SPT), 30.2% (RAST) and more frequent in children with a history of hay fever (SPT: OR 11.7, 5.5-24.7; RAST: OR 10.6, 4.3-26.4). This difference was most pronounced for sensitization to pollen allergens. The sensitivity, specificity, positive and negative predictive values (PPV, NPV) for SPT and RAST were 65.6, 83.7, 11.9, 98.6 and 79.3, 71.6, 9.3, 99.0, respectively, with differences for specificity being significant (p < 0.001). Whereas NPV were equally high for SPT (99.2) and RAST (99.3), the incidence of hay fever cases were predicted rather poorly though somewhat better by SPT than by RAST (PPV 16.7 vs. 9.8; p < 0.001) initially. With increasing cut-off point for RAST reactivity, the PPV increased and reached 25.0 at 17.5 kU/l, whereas the NPV decreased to 97.9, which was lower than that of SPT reactivity (p < 0.01). At the cut-off point of 1.5 kU/l almost identical predictive values for SPT and RAST were obtained. SPT and RAST perform better in the negative than positive prediction of hay fever cases in epidemiological studies. Differences in the predictive capabilities depend on the chosen cut-off point for RAST reactivity.

Diesel fumes and the rising prevalence of atopy: an urban legend?

Recently, the incidence of allergic diseases has increased in most industrialized countries of the world. Persistent exposure to particulate air pollution from motor vehicles has been implicated as one of the factors that is responsible for the observed increased prevalence of atopy. Epidemiologic studies conducted in different parts of the world have demonstrated an important association between ambient levels of motor vehicle traffic emissions and increased symptoms of asthma and rhinitis. Additionally, recent human and animal laboratory-based studies have shown that particulate toxic pollutants, and in particular diesel exhaust particles (DEP), can enhance allergic inflammation and induce the development of allergic immune responses. In this article, our current understanding of the mechanisms by which pollutants such as DEPs enhance the underlying allergic inflammatory response is reviewed, and the evidence that supports the causative link between particulate air pollution from motor vehicles and increasing allergic diseases is discussed.

A relatively high prevalence and severity of asthma, allergic rhinitis and atopic eczema in schoolchildren in the Sultanate of Oman

OBJECTIVES

Although asthma, allergic rhinitis and eczema are among the most common chronic diseases in children worldwide, there is very limited information about the burden of these conditions in Oman. The aim of this study was to determine the prevalence and severity of symptoms of asthma, allergic rhinitis and eczema in Omani schoolchildren using the International Study of Asthma and Allergies in Childhood (ISAAC) Phase I questionnaire.

METHODS

An Arabic version of the ISAAC Phase I questionnaire was completed by parents of 3893 children aged 6-7 years and self-completed by 3174 children aged 13-14 years, randomly selected from a nationwide sample of public schools.

RESULTS

The prevalence rates of reported diagnoses of asthma, allergic rhinitis and eczema were higher in older children (20.7%, 10.5% and 14.4% compared with 10.5%, 7.4% and 7.5%, respectively, in young children). In young children, 277 were current wheezers and of these 40.8% had sleep-disturbing wheeze at least once a week and 45.1% had speech-limiting wheeze during the past year. Similarly, 283 older children were current wheezers, and of these 30.0% had sleep-disturbing wheeze at least once a week and 37.5% had speech-limiting wheeze during the past year. Exercise-induced wheeze was higher in older children (19.2% vs 6.9%; P < 0.001). Allergic rhinitis and eczema were also associated with significant sleep disturbance and limitation of activity in both age groups.

CONCLUSION

Allergic conditions in Omani schoolchildren are common and associated with significant morbidity. Further research is required to identify the local risk factors for allergy to allow better understanding and management of these conditions.

Breastfeeding and the prevalence of symptoms of allergic disorders in Japanese adolescents

BACKGROUND

Environmental factors acting early in life are key determinants of the incidence of allergic disease. Whether breastfeeding is protective against allergic disorders remains controversial.

OBJECTIVE

The present cross-sectional study examined the relationship between feeding patterns in the first 3 months of life and the prevalence of symptoms of wheeze, atopic eczema, and rhinoconjunctivitis during the past 12 months in Japanese adolescents.

METHODS

The subjects were 5614 of 9008 students (62%) aged 12-15 years from all public junior high schools in Suita, Japan in 2001. This study used the diagnostic criteria of the International Study of Asthma and Allergies in Childhood. Adjustment was made for gender, grade, number of older siblings, and parental history of allergy.

RESULTS

Feeding pattern was unrelated to the prevalence of wheeze or rhinoconjunctivitis. The prevalence of atopic eczema was significantly higher in children who had been breastfed than in artificial milk feeders (adjusted odds ratios = 1.40 and 1.56, 95% confidence intervals: 1.01-1.98 and 1.13-2.22 for mixed milk intake and breastfeeding only vs. artificial milk consumption, respectively; P = 0.01 for linear trend). When children were divided according to a positive or negative allergic history in at least one parent, an increased prevalence of atopic eczema associated with breastfeeding was found in children with a negative parental allergic history compared with those with a positive parental allergic history.

CONCLUSION

The findings suggest that breastfeeding may be associated with an increased prevalence of atopic eczema, especially among children without a parental history of allergy.

Prevalence of self-reported allergic and non-allergic rhinitis symptoms in Stockholm: relation to age, gender, olfactory sense and smoking

OBJECTIVE

To estimate the prevalence of isolated self-reported allergic and non-allergic rhinitis symptoms in an adult population and to explore the relations to age, gender, olfaction and smoking habits.

MATERIAL AND METHODS

Self-judged health and environmental exposures were investigated by means of a questionnaire survey administered to a stratified random sample of 15,000 adults in Stockholm County.

RESULTS

A total of 10,670 individuals were included in the analysis, corresponding to a response rate of 73%. The results revealed a high prevalence of self-reported non-allergic rhinitis, 19%, almost as high as the prevalence of self-reported allergic rhinoconjunctivitis, 24%. In contrast to current clinical opinion, we did not find a significant increase in the prevalence of non-allergic symptoms with increased age. There were no statistically significant gender differences in the prevalence of either allergic or non-allergic symptoms. A reduced sense of smell was twice as common in the non-allergic group, 23%, as in the healthy population. The prevalence of rhinitis symptoms differed according to smoking habits.

CONCLUSION

Both self-reported allergic rhinitis symptoms and non-allergic nasal symptoms are frequent in the population sample. Self-reported non-allergic nasal symptoms seem to occur independent of age and reduced olfactory sense is a common complaint among these subjects. The prevalence of self-reported allergic and non-allergic nasal symptoms did not differ much between men and women or between individuals with different smoking habits.

The ecological relationship of tobacco smoking to the prevalence of symptoms of asthma and other atopic diseases in children: the International Study of Asthma and Allergies in Childhood (ISAAC)

This study examined the relationship between parental smoking and asthma and other atopic diseases at the ecological level. The prevalence of atopic symptoms in 6-7- and 13-14-year old children was assessed in 91 centres (from 38 countries) and 155 centres (from 56 countries) respectively in the International Study of Asthma and Allergy in Childhood (ISAAC). These symptoms were related to prevalence of tobacco smoking for each country by gender as reported by the World Health Organisation. There was a significant negative association between the prevalence of smoking by men and the prevalence of symptoms of asthma and rhinitis, but not eczema in the 13-14-year age group. There was a significant positive relationship between prevalence of smoking by women and prevalence of wheeze in the last 12 months, but not for any other symptoms in the 13-14-year age group. In the 6-7-year age group, there was a significant negative correlation between prevalence of smoking by men and the prevalence of wheeze causing sleep disturbance and a close to significant negative association at the 5% level with the prevalence of wheeze in the last 12 months and rhinitis. Thus, for the countries that are included in this analysis, countries that have high adult male smoking rates have a lower risk of asthma and rhinitis symptoms in children. It should be stressed that this analysis does not involve information on individual exposures and therefore does not contradict the well-established association of active and passive smoking in individuals with the occurrence of asthma symptoms in the same individuals. Rather, it indicates that this well-established individual-level association does not account for the international differences in asthma prevalence, and that other risk factors for asthma must be responsible for the observed international patterns.

Intranasal corticosteroids versus topical H1 receptor antagonists for the treatment of allergic rhinitis: a systematic review with meta-analysis

OBJECTIVE

We performed a systematic review of randomized, controlled trials to determine whether intranasal corticosteroids offered an advantage over topical antihistamines in the treatment of allergic rhinitis.

DATA SOURCES

We searched for studies using MEDLINE, Embase, Cinahi, and Cochrane databases, pharmaceutical companies, and references of included trials.

STUDY SELECTION

Criteria for considering trials included: 1) published randomized controlled trials; 2) single- or double-blind studies; and 3) presence of one of the following clinical outcomes: nasal symptoms, eye symptoms, global symptoms evaluation of quality of life and side effects.

RESULTS

Nine studies including 648 subjects (mean age 30.4 years, range 13 to 73) with allergic rhinitis were selected. Intranasal corticosteroids produced significantly greater reduction of total nasal symptoms (standardized mean difference -0.36, 95% confidence interval -0.57 to -0.14), sneezing (-0.41, -0.57 to -0.24), rhinorrhea (-0.47, -0.64 to -0.29), itching (-0.38, -0.56 to -0.19), and nasal blockage (-0.86, -1.07 to -0.64) than did topical antihistamines. There was no significant difference between treatments for ocular symptoms (-0.07, -0.27 to 0.12). The effects on sneezing, rhinorrhea, itching, and ocular symptoms were significantly heterogeneous between studies. Other outcomes (total nasal symptom score and nasal blockage) were homogeneous between studies. Subgroup and sensitivity analysis suggested that most of the heterogeneity of outcomes could be explained on the basis of the methodologic quality of studies.

CONCLUSIONS

Intranasal corticosteroids produced greater relief of nasal symptoms than did topical antihistamines (topical H1 receptor antagonists). However, there was no difference in the relief of the ocular symptoms.