The association of individual allergen reactivity with respiratory disease in a national sample: data from the second National Health and Nutrition Examination Survey, 1976-80 (NHANES II)

Mold and human health: separating the wheat from the chaff

The term "mold" is utilized to define the ubiquitous fungal species commonly found in household dust and observed as visible multicellular filaments. Several well-defined human diseases are known to be caused or exacerbated by mold or by exposure to their byproducts. Among these, a solid connection has been established with infections, allergic bronchopulmonary aspergillosis, allergic fungal rhinosinusitis, hypersensitivity pneumonitis, and asthma. In the past decades, other less-defined and generally false conditions have also been ascribed to mold. We will herein review and critically discuss the available evidence on the influence of mold on human health.

Alternaria sensitization and allergic rhinitis with or without asthma in the French Six Cities study

BACKGROUND

Allergic sensitization to Alternaria has been related to asthma in various studies, but its association with allergic rhinitis is still controversial.

OBJECTIVES

The aim of this study was to assess at the population level the relationships in childhood between Alternaria sensitization and 'past-year rhinoconjunctivitis' (PYRC), 'ever hay fever' (EHF) and 'ever allergic rhinitis caused by allergens other than pollens' (EAR) according to the presence or the absence of asthma.

METHODS

This study is part of the Six Cities Study, the French contribution to the International Study of Asthma and Allergies in Childhood (ISAAC) Phase II. Children underwent skin prick test (SPT) to Alternaria and parents filled a standardized medical questionnaire.

RESULTS

Some 6726 children with a mean age of 10 years were examined. The overall prevalence of Alternaria sensitization was 2.8%, 0.8% for monosensitization. Prevalences of symptoms in sensitized children were 27.7% for PYRC, 27.0% for EHF and 30.4% for EAR. Adjusted Odds Ratios (OR) between Alternaria sensitization and allergic rhinitis phenotypes were 2.34 (95% confidence interval: 1.51-3.63) for PYRC, 2.40 (1.65-3.50) for EHF and 2.95 (2.05-4.23) for EAR. The relationship still remained in the case of monosensitization to Alternaria for both PYRC and EAR when excluding the asthmatic children [OR = 3.87 (1.54-9.78) and 2.88 (1.10-7.55) respectively].

CONCLUSION

In our population-based sample of children, we found a link between Alternaria sensitization and allergic rhinitis, independently of asthma, which is compatible with the mechanisms of deposition of Alternaria in the upper airways.

Effects of a DNA vaccine in an animal model of Alternaria alternata sensitivity

Sensitivity to the fungus Alternaria is associated with asthma persistence and severity. Current therapeutic options for treating Alternaria-induced airway inflammation are limited. In this study, Brown Norway rats are used to study the effectiveness of a DNA-based vaccine delivered to the airway in attenuating the response to a major Alternaria allergen, rAlt a 2. Compared to untreated sensitized animals, or animals receiving an "out-of-frame" DNA-based vaccine, animals treated with "in-frame" DNA vaccine showed an attenuation in specific IgE antibody titers to rAlt a 2, an increase in IgG(2b) (a Th1 response), a reduction in spontaneous IL-13 release by peribronchial lymph node cell suspensions, and an attenuation in the decrease in total lung capacity 72 h post-allergen challenge. Further, histopathologic examination of the lung tissues revealed reduced pulmonary inflammation post-allergen challenge in the DNA-vaccine-treated compared to sensitized, untreated animals. We conclude that a DNA-based vaccine delivered to the airway significantly influences the immunologic, pulmonary physiologic, and histological alterations induced by challenge with a major Alternaria allergen, rAlt a 2, in sensitized animals.

The association of allergic symptoms with sensitization to inhalant allergens in childhood

Although it is generally agreed that sensitization is an important risk factor for allergic diseases, the extent to which sensitization accounts for allergic symptoms in children is controversial. As part of the Aalst Allergy Study, this cross-sectional study investigated the prevalence of allergic symptoms and their association with sensitization in an unselected population of Flemish children aged 3.4-14.8 yr. Skin prick testing with the most common aeroallergens was performed and allergic symptoms were documented by a parental questionnaire. In the children older than 6 yr, a significant association of current wheezing, current dyspnea, airway hyperreactivity, rhinoconjunctivitis, and current eczema with sensitization was found, while in the pre-school children these associations were less pronounced. The association with sensitization was strongest for rhinoconjunctivitis and current respiratory symptoms - the association was less striking for children with current eczema. The impact of a positive family history of allergy on the association with sensitization was more important for eczema than for the other analyzed allergic symptoms. Persistent and late-onset wheezers were significantly more likely than non-wheezers and transient early wheezers to be associated with sensitization and a personal history of rhinoconjunctivitis. Late-onset wheezing was associated with a positive family history of allergy, while transient early wheezing was associated with day-care attendance. An association with eczema was found for all three childhood wheezing phenotypes. The association of allergic symptoms with sensitization is significant in the older but less pronounced in pre-school children and is more pronounced for current allergic symptoms. Diagnosis and disease definition of allergy symptoms remains difficult at pre-school age. The influence of a positive family history of allergy on the association of the respective allergic symptoms with sensitization was most important for eczema. Our data confirm the atopic characteristics of the different wheeze phenotypes.

Determination of parameters related to nasal inspiratory pressures in children utilizing valved-holding chambers (valved spacers)

OBJECTIVE

The administration of medication by the nasal route using valved spacers, may be an alternative for the concomitant treatment of allergic rhinitis and asthma. The aim of this study was to determine if children are capable, in using a spacer and face mask, of opening the inspiratory valve using only nasal inhalation.

METHODS

Prospective cross-sectional. The study included 85 children aged 4-9 years. Four types of valved spacers connected to a digital vacuum manometer were evaluated. The patients were prompted to inhale through their nose and the pressure reached in the first curve, maximal peak and time between the start of the inspiratory action and the first effective inspiration (opening of the valve) were determined. The results were compared with factors such as age, weight, BMI, gender, and presence of rhinitis or asthma.

RESULTS

In two of the spacers, the valve opened in 98.8% of the tests with nasal inspiration only. The spacer ACE holding chamber showed initial and maximal inspiratory pressures that were significantly greater than with the others (p<0.001). No correlation was observed between the parameters examined for each spacer and the patient variables considered.

CONCLUSION

The results suggest that children 4-9 years old are able to open the spacer valve with only nasal inspiration. The spacer ACE holding chamber was shown to be significantly more effective than the others tested. Studies that demonstrate that air inspired nasally reaches the lungs effectively are necessary so that this airway can be utilized for the administration of therapeutic agents.

[Exposure to fine air particles and occurrence of allergic diseases: results of ISAAC-France phase 2]

To evaluate whether fine air particles could be involved in the occurrence of atopy and allergic diseases, we performed a cross-sectional epidemiological survey involving primary schoolchildren living in six French towns with contrasted air pollution levels. Air pollution was measured during a week in the school yards and by standard air monitoring networks. Children get an examination in school looking for atopic dermatitis and bronchial hyperresponsiveness assessed by a standardized run test. Besides, parents or guardians provided past medical history and environmental data, especially on passive smoking. Overall, 5,338 children, aged 10.4 (+/-0.7) years, coming from 108 different schools and 401 different classes were included in the survey. Taking into account potential confounders, high exposure to proximity PM(2.5) was linked to a higher point prevalence of atopic dermatitis and hyperresponsiveness, to a higher cumulative prevalence of allergic asthma and a higher sensitization rate to common indoor allergens. Thus, these data suggest that chronic exposure to urban fine particles could be a risk factor for atopy, hyperresponsiveness and asthma.

Early-lifetime exposure to air pollution and allergic sensitization in children with asthma

Observations on the association between exposure to common outdoor air pollutants and allergic sensitization have not been consistent. Little research has been done on the effects of prenatal exposure or the effect among asthmatics. The association between prenatal and early-life exposures and outdoor air pollutants with allergic sensitization was examined within a cohort of 170 children ages 6-11 years with asthma, living in the Central Valley of California. Allergic sensitization was ascertained by skin-prick tests to 14 allergens. Prenatal and early-life exposure to ozone (O(3)), nitrogen dioxide (NO(2)), carbon monoxide (CO) and particulate matter with a median aerodynamic diameter < 10 micro m (PM(10)) was reconstructed for each child. Models were developed for sensitized to (a) any allergen, (b) at least one outdoor allergen, and (c) at least one indoor allergen. In multivariable analyses, higher exposure to CO during pregnancy was associated with an increased risk of sensitization to at least one outdoor allergen. The largest effect was seen for the association between exposure to 8-hour daily maximum CO during pregnancy and sensitization to at least one outdoor allergen. (OR = 1.55 (95% CI: 1.01, 2.37)) per interquartile range (IQR) increase.) Similar effects estimates were seen for 2nd trimester exposure to CO, but these were less precisely estimated (OR = 1.45 (95%CI: 0.90, 2.35)). No significant associations with the pollutants were seen for sensitization to allergens in general or to at least one indoor allergen. Exposure to traffic-related pollutants during pregnancy may increase the risk of sensitization to outdoor allergens among asthmatic children.

Parent report of pests and pets and indoor allergen levels in inner-city homes

BACKGROUND

Guidelines recommend allergen avoidance for patients with allergic asthma, but direct measurements of home allergen levels are not available to most physicians. Parent report of indoor allergen exposure is a potentially convenient and inexpensive surrogate measure of exposure, although validity of parent report to estimate indoor allergen levels is not well established.

OBJECTIVE

To determine if parent-reported pest and pet exposures can identify patients with clinically relevant allergen exposure.

METHODS

Parents of 300 inner-city children completed a survey about pests (cockroaches and mice) and furred pets (dogs and cats). Settled dust samples were obtained for Bla g 1, Mus m 1, Can f 1, and Fel d 1 from kitchens and bedrooms.

RESULTS

Parent reports were associated with clinically relevant levels of Bla g 1, Mus m 1, Can f 1, and Fel d 1 (P < .001 for all). For example, when parents reported cockroaches were present, 86% of homes had settled dust Bla g 1 levels of 1 U/g or higher, and when they reported mice were present, 90% had Mus m 1 levels greater than 500 ng/g. Report of pets was also predictive of clinically meaningful allergen levels. Parent-reported absence of pets provided assurance that allergen levels were below relevant thresholds (negative predictive value, 80%-98%). However, parent-reported absence of pests did not provide assurance of low levels of these allergens (negative predictive value, 38%-75%).

CONCLUSIONS

Since direct measurement of indoor allergens is not always feasible, especially in the inner city, parent report of pests and pets may be sufficient to recommend environmental control practices for sensitized children. Negative parent reports of pests are not sufficient evidence of low pest allergen exposure.

Changes in skin test reactivity among adults with atopic disease: a 3-year prospective study

BACKGROUND

Our knowledge about longitudinal predictors of atopy is limited.

OBJECTIVES

To describe changes in skin test reactivity during a 3-year period in a sample of adolescents and adults with atopic disease and to identify factors of importance for these changes.

METHODS

From a sample of 1,186 candidates, ranging in age from 14 to 44 years, who in a screening questionnaire reported symptoms suggestive of respiratory allergic disease, 344 individuals with a positive skin prick test (SPT) result concomitantly with asthma and/or rhinitis were clinically studied on 2 occasions, 3 years apart.

RESULTS

In total, 134 (39% of the study population) had a different SPT result at follow-up compared with baseline, based on a diagnostic criterion of 3 mm for a positive test result; 77 (22%) developed de novo sensitizations to 1 or more allergens, 45 (13%) had remission of 1 or more sensitizations, and 12 (4%) both gained and lost sensitizations. Female sex (odds ratio = 1.90 [1.02-3.57], P = .04) significantly predicted incidence of 1 or more sensitizations.

CONCLUSIONS

Four of 10 adults with atopic disease will have changes in SPT status during a 3-year period, and most will gain new sensitizations. Women with atopic disease are at increased risk of developing new sensitizations compared with men.

Occupational rhinitis in damp and moldy workplaces

BACKGROUND

Numerous studies confirm the association between exposure to indoor air dampness and molds and different health outcomes. Of these, upper respiratory tract problems are the most commonly reported work-related symptoms in damp indoor environments. The aim of this study was to describe a clinically investigated patient series with occupational rhinitis induced by molds.

METHODS

Nasal provocation test (NPT) with commercial fungal allergens was performed in 369 patients during 1995-2004 at the Finnish Institute of Occupational Health. Of these, 60 (16%) were positive. In addition to positive NPT, the diagnosis of occupational rhinitis was based on verified exposure to molds, work-related nasal symptoms, and clinical investigations. We wanted to review the patient files of these 60 patients retrospectively, and 56 patients gave their informed consent.

RESULTS

The mean age of the patients was 43.7 years (SD +/- 9.5). Fifty (89.3%) patients were women. In 23% of the patients, IgE-mediated allergy to molds could be established. Atopy significantly increased IgE sensitization to molds (OR, 10.3 [95% CI, 2.0-52.5]). The most common mold to induce occupational rhinitis was Aspergillus fumigatus. Exposure time was over 5 years in 63% of the patients. Association between the IgE sensitization to molds and exposure level was statistically significant (Fisher's exact test, p = 0.046).

CONCLUSION

This is the first clinically investigated series on occupational rhinitis in relation to a moldy environment. Based on our findings, we conclude that molds growing in conjunction with moisture damages can induce occupational rhinitis. IgE-mediated allergy to molds was not common. Atopy and significant exposure level increased IgE sensitization to molds. zri00508.

Risk factors for asthma and other allergic diseases in seasonal rhinitis

BACKGROUND

Rhinitis and asthma are common comorbidities. The aim of this study was to determine the risk factors for asthma and other allergic diseases in seasonal rhinitis (SR) patients.

METHODS

Records of 922 patients diagnosed as SR between 1991 and 2005 were evaluated retrospectively. Patients were grouped according to the results of our standard skin prick tests as follows: I-No sensitization: no sensitization to any allergen; II-Mono-pollen sensitization: sensitization to only one pollen allergen; III-Poly-pollen sensitization: sensitization to more than one pollen allergen; IV-Mite sensitization: sensitization to mite with or without any other allergen sensitization.

RESULTS

The mean age of the patients was 29.5 +/- 9.6 and 587 patients (63.2%) were females. Age at onset of SR was median 21 years (16-29 years). Of the 922 patients, 99 had no sensitization, 335 had poly-pollen sensitization, 346 had mono-pollen sensitization, and 142 had mite sensitization. The most prevalent allergens were P. pratense (85.3%) and O. europae (31.5%). No sensitization group as compared to poly-pollen sensitization group had significantly higher prevalence of asthma as a single accompanying disease (14.1%, p < 0.05). Mono-pollen sensitization was significantly associated with lower risk of any accompanying allergic disease (OR: 0.7, 95% CI 0,5-0,9) while no sensitization group (OR: 2.8, 95% CI 1.3-5.9) and mite sensitization were associated with asthma (OR: 2.3, 95% CI 1.2-4.4).

CONCLUSION

SR is a condition that presents with different phenotypes. The group with no sensitization and mite sensitization has the highest prevalence of asthma while SR patients with mono-pollen sensitization are unlikely to have an accompanying allergic disease, including asthma.

Validity of the interview on pets kept at home for predicting the actual domestic expsoure to their specific allergens. Krakow inner city area study

The aim of the study was to describe the exposure to dog (Can f 1) and cat (Fel d 1) allergens within homes of very young children living with and without pets, and to assess the validity of the interview on pets for predicting the actual exposure to pet allergens in house dust. House dust samples were collected in 275 dwellings from the mattresses, children’s bedroom and kitchen floors. In the laboratory, dust samples were analyzed for Can f 1 and Fel d 1 using monoclonal antibody enzyme-linked immunosorbent assays (ELISA). The majority of households (79.3%) had neither a dog nor a cat living in the home over the past 6 months preceding the survey. Dog allergen above 2 μg/g dust were found in 22.5% of homes and 14.2% of homes contained dog allergen above 10 μg/g of house dust. In the total study sample, cat allergen above 1 μg/g of dust were found in 12.7% of homes, and 3.3% of homes contained Fel d 1 levels greater than 8 μg/g of dust. The majority of children (75.0%) with reported ownership of dogs were exposed to Can f 1 levels above 2 μg/g of house dust, and 73.1% of children with cats at home were exposed to Fel d 1 concentrations above 1 μg/g house dust. The results of the study showed that post-test probability of the true exposure to Can f 1 above 2 μg/g dust in houses with positive interview on indoor dogs was 75.0% (95%CI: 61.7–84.8%). On the other hand, the prediction of exposure estimated from the interview data on indoor dogs produced 12.6% of false negatives (95% CI: 9.9–15.8%). Similarly, the post-test probability of the true exposure to Fel d 1 above 1 μg/g dust in houses with positive interview on indoor cats was 73.1% (95%CI: 55.1–85.7%). On the other hand, the interview data produced 6.4% false negatives (95% CI: 4.6–9.0%). In conclusion, the study demonstrated that homes in Poland with pet ownership are important reservoir of Can f 1 and Fel d 1 allergens with levels that might induce allergic symptoms. Even in homes of children without a dog or cat indoors, there was a higher prevalence of pet allergens at the levels above allergic sensitisation thresholds. This may have an important implication for epidemiologic studies on pet related allergy and prevention practice.

Alternaria measures in inner-city, low-income housing by immunoassay and culture-based analysis

BACKGROUND

Sensitivity to Alternaria allergens has been associated with severe asthma and life-threatening exacerbations, and a high prevalence of Alternaria sensitivity has been reported among inner-city populations. Traditionally, epidemiologic studies have measured indoor Alternaria concentrations by cultural analyses; however, the number of viable spores may not be a good proxy for allergen levels. Furthermore, other genera share epitopes with Alternaria that may contribute to the allergenic effect.

OBJECTIVE

To compare measures of Alternaria antigen by enzyme-linked immunosorbent assay with measures of Alternaria and cross-reactive genera (Ulocladium, Curvularia, Epicoccum, and Stemphylium) by cultural analysis.

METHOD

Antigen assays and cultural analyses were performed on vacuum-collected bed dust samples collected between June 18, 2002, and February 9, 2004, from 3 inner-city, low-income public housing developments.

RESULTS

Alternaria antigen was found in all bed dust samples regardless of season. However, culturable Alternaria, Ulocladium, Curvularia, Epicoccum, and Stemphylium were only found in 50%, 35%, 6%, 11%, and 0% of bed samples, respectively. No correlations were found between Alternaria antigen and culturable concentrations of Alternaria or of its cross-reactive genera except for marginal correlation with Ulocladium culturable concentrations.

CONCLUSIONS

The results confirm that exposure to Alternaria antigens and allergens can occur even in the absence of culturable Alternaria or its cross-reactive genera, so further refinement and use of assays are essential for characterizing the distribution and determinants of indoor fungal allergen levels forsensitive populations.

Importance of mold allergy in asthma

Fungal exposure is hypothesized (controversially) to contribute to asthma development and to trigger symptoms in patients with asthma. The ubiquity of environmental fungal exposure makes a careful review of evidence essential. Evidence that exposure to high concentrations of fungal spores, antigens, or metabolites is associated with asthma development is limited. However, because mechanisms of asthma genesis are poorly understood, so too are the mechanisms of this potential association. This association is not proof of causality. Stronger evidence supports the hypothesis that fungal exposure triggers symptoms in asthmatic individuals. Proposed mechanisms have been tested and correlations between exposure and symptoms demonstrated. Though some correlations remain speculative, controlled studies could test such hypotheses. Because asthma is common and fungal exposure is ubiquitous, it is surprising that asthmatics don't have more symptoms when exposed to fungi. Fortunately, symptoms are dose dependent, creating an opportunity to develop clinically effective interventions. Given the right guidance, even patients with severe asthma can create healthy indoor environments.

[Frequency of allergic rhinitis in selected regions of Poland. City vs countryside analysis]

PURPOSE

Study of frequency of allergic rhinitis in selected regions of Poland in cities and countryside.

MATERIAL AND METHODS

8913 respondents, from Warszawa, Katowice, Lublin and Zamojszczyzna (countryside), answered a questionnaire based on ECRHS II and ISAAC. The respondents were drawn from PESEL ID numbers. They were divided into three groups: 6-7 years, 13-14 and 20-44 years, both sexes.

RESULTS

21-23% adults living in the city and 12% living in the countryside confirmed some type of sensitization, including allergic catarrh. In children the same symptoms are more frequent and reported in 23-27% of those living in city and 17% of those living in the countryside. Sneezing, running or obstructed nose not related to cold, fever or flu were reported by 22% of the adults living in Zamojszczyzna and 33-42% of those living in the cities. The symptoms are reported in 20% children living in the countryside and 29-39% of those living in the cities. All of results are statistical significant.

CONCLUSIONS

Study of frequency of allergic rhinitis in selected regions of Poland shows that results are similar with analysis on the world. Connection between urban development and occurrence of allergic rhinitis was confirmed. Allergic rhinitis is more frequently in group of people living in cities than people living on countryside. Probably allergic rhinitis is not integrally examined in adults group.

Quantification of atopy and the probability of rhinitis in preschool children: a population-based birth cohort study

BACKGROUND

Atopy quantification using IgE levels/skin test diameter (SPT-MWD) may better predict the expression of rhinitis than using atopy as a dichotomous variable.

OBJECTIVE

To investigate the association between the presence, temporal pattern and severity of rhinitis in preschool children and specific IgE levels/SPT-MWDs.

METHODS

Children were followed prospectively to age 5 years in a whole-population birth cohort study. We administered questionnaires (n = 815), skin prick tested children (n = 717) and measured specific serum IgE (n = 478) to inhalant and food allergens. Main outcomes were current rhinitis (CR) and current rhinoconjunctivitis (CRC).

RESULTS

The prevalence of CR and CRC was 26.1% and 12.1%, respectively. The risk of CR and CRC increased significantly with increasing IgE to grass, mite and cat; CRC was also associated with increasing IgE to dog and peanut. Similarly, increasing SPT-MWDs to inhalant allergens were significantly associated with CR and CRC. This association was also shown for grass within the group of atopic children. Perennial and seasonal rhinitis were associated with increasing IgE/SPT-MWD to mite and grass, respectively. Moderate/severe rhinitis was associated with increasing IgE/SPT-MWD to grass. In a multivariate analysis, increasing levels of IgE/SPT-MWD to grass were the strongest independent predictors of both CR (for IgE: OR 1.42, 95% CI 1.23-1.64, P < 0.001) and CRC (for IgE: 1.51, 1.30-1.76, P < 0.001).

CONCLUSION

The probability of CR/CRC increases with increasing specific IgE levels or SPT-MWD. With respect to allergic rhinitis, the absolute levels of specific IgE antibody or the size of SPT wheal offer more information than just the presence/absence of sensitization.

Asthma cases attributable to atopy: results from the Third National Health and Nutrition Examination Survey

BACKGROUND

The percentage of asthma cases attributable to atopy is the subject of debate.

OBJECTIVES

The objectives were to estimate the percentage of asthma cases in the US population attributable to atopy and to examine associations between allergen-specific skin tests and asthma.

METHODS

Data were obtained from the Third National Health and Nutrition Examination Survey, in which subjects age 6 to 59 years were skin tested with 10 allergens. Atopy was defined as at least 1 positive allergen-specific test. Doctor-diagnosed current asthma was assessed by questionnaire.

RESULTS

In the United States, 56.3% of the asthma cases were attributable to atopy, and that percentage was greater among males than females, among persons in the highest education category than in lower education categories, and among persons living in highly populated metropolitan areas than in all other areas. Each allergen-specific test was strongly associated with asthma before adjustment (odds ratios varied from 2.1 to 4.5); however, after adjustment by all the allergens, only tests to cat, Alternaria, white oak, and perennial rye were independently associated with asthma. Perennial rye was inversely associated with asthma. Of the 10 allergens, a positive response to cat accounted for the highest percentage of asthma cases (29.3%).

CONCLUSION

About half of the current asthma cases in the US population represented by the Third National Health and Nutrition Examination Survey were attributable to atopy. Some allergen-specific skin tests were not independently associated with asthma.

CLINICAL IMPLICATIONS

If atopy could be prevented or reversed, or its effect on asthma blocked, then a large percentage of asthma cases in the US population could be prevented.

High prevalence of skin test positivity in severe or difficult-to-treat asthma

BACKGROUND

Skin tests are considered the gold standard for detecting allergen-specific immunoglobulin E (IgE) in the clinical setting and are an important tool for diagnosing and managing allergic asthma.

OBJECTIVE

To assess the prevalence of skin testing in patients > or = 12 years enrolled in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study.

METHODS

Patients were asked whether they had ever been skin tested and, if so, they were asked to provide the test results. Clinical characteristics were used to compare positive (ST+), negative (ST-), and skin test not done (STND) patients.

RESULTS

Of 2,985 patients eligible, 85.8% recalled being skin tested. Of those tested, 93.5% were positive (allergist 95.7%, pulmonologist 87.3%). A high proportion of Whites (93.5%) and non-Whites (94.0%) were ST+; however, more non-Whites had never been skin tested (21.7% vs. 12.3%, respectively; p < 0.0001). Total serum IgE was 104.6 IU/mL for ST+ patients, 87.1 IU/mL for STND patients, and 32.4 IU/mL for ST- patients. Age at asthma onset, duration of asthma, and the prevalence of atopic disorders and asthma triggers differentiated the ST+ from the ST- group. Disease severity appeared similar between the two groups. In general, values for STND patients were closer to the ST+ group, suggesting that those not tested would have been ST+ if administered a test.

CONCLUSIONS

The prevalence of ST+ patients was high in allergy and pulmonology practices, and in White and non-White patients. These data support the utility of a more complete allergic evaluation in severe asthmatics. Skin testing appears associated with disease pathophysiologies in asthma.

Comparison of patterns of allergen sensitization among inner-city Hispanic and African American children with asthma

BACKGROUND

Among Hispanics, the largest minority ethnic group in the United States, asthma prevalence is increasing, particularly in inner-city neighborhoods. Although allergen sensitization among asthmatic African Americans has been extensively studied, similar details are not available for Hispanic children.

OBJECTIVES

To examine patterns of allergen sensitization, including the association with illness severity, in asthmatic children overall and in Hispanic and African American children living in a socioeconomically disadvantaged area of New York City.

METHODS

A retrospective medical record review of asthmatic children attending a community hospital in the South Bronx area of New York City was performed. Information abstracted included demographics, asthma severity classification, reported exposures to indoor allergens, and results of allergy testing.

RESULTS

Among 384 children in the analysis, 270 (70.3%) were Hispanic and 114 (29.7%) were African American. Sensitization to indoor and outdoor allergens, respectively, did not differ between Hispanic (58.5% and 27.0%) and African American (58.8% and 32.6%) children. Allergen sensitization exhibited a direct, significant association with asthma severity for indoor allergens for the 2 ethnic groups combined and for Hispanics separately but not between asthma severity and outdoor allergens (P < .01). No correlation was found between self-reported allergen exposure and sensitization.

CONCLUSIONS

Patterns of allergen sensitization among inner-city Hispanic asthmatic children resemble those among African American children, a finding that is likely explained by the similarity in levels of environmental exposures. With the increasing prevalence of asthma among inner-city Hispanic children, skin testing should be used frequently for objective evaluation of asthma in this ethnic group.

Exposure to Alternaria alternata in US homes is associated with asthma symptoms

BACKGROUND

Exposure to the fungus Alternaria alternata is a risk factor for asthma. Few studies have examined Alternaria exposures in indoor environments.

OBJECTIVE

We examined whether exposure to A alternata in US homes was associated with asthma-related outcomes.

METHODS

The data for this study were collected as part of the National Survey of Lead and Allergens in Housing. This cross-sectional study surveyed a nationally representative sample of 831 housing units inhabited by 2456 individuals in 75 different locations throughout the United States. An interviewer-administered questionnaire obtained information on demographics, household characteristics, and occupants' health status. Exposure to A alternata was assessed by measuring concentrations of A alternata antigens in vacuumed dust samples using a polyclonal anti-A alternata antibody assay. Dust samples were collected from a bed, a sofa, or a chair, and from bedroom, living room, and kitchen floors.

RESULTS

Lifetime prevalence of doctor-diagnosed asthma was 11.2%, and 6.9% of the study subjects reported active asthma symptoms in the past 12 months. The prevalence of current symptomatic asthma increased with increasing Alternaria concentrations in US homes; higher levels of A alternata antigens increased the odds of having asthma symptoms in the past year (relative to the lowest tertile, adjusted odds ratio was 1.52, 95% CI, 0.90-2.55 for the 2nd tertile; and 1.84, 95% CI, 1.18-2.85 for the 3rd tertile).

CONCLUSION

Exposure to A alternata in US homes is associated with active asthma symptoms.

CLINICAL IMPLICATIONS

Measures that reduce indoor exposure to A alternata may help control asthma exacerbations.

Spectrum of noninfectious health effects from molds

Molds are multicellular fungi that are ubiquitous in outdoor and indoor environments. For humans, they are both beneficial (for the production of antimicrobial agents, chemotherapeutic agents, and vitamins) and detrimental. Exposure to mold can occur through inhalation, ingestion, and touching moldy surfaces. Adverse health effects may occur through allergic, infectious, irritant, or toxic processes. The cause-and-effect relationship between mold exposure and allergic and infectious illnesses is well known. Exposures to toxins via the gastrointestinal tract also are well described. However, the cause-and-effect relationship between inhalational exposure to mold toxins and other untoward health effects (eg, acute idiopathic pulmonary hemorrhage in infants and other illnesses and health complaints) is controversial and requires additional investigation. In this report we examine evidence of fungal-related illnesses and the unique aspects of mold exposure to children. Mold-remediation procedures are also discussed.

Asthma exacerbations. 2: aetiology

The natural history of asthma involves relatively stable periods that are often punctuated by significant exacerbations of symptoms. There are many aetiologies that may lead to an increase in asthma severity including respiratory infection (bacterial/viral), allergens, irritants, and occupational exposures. Each trigger probably acts through different mechanisms, but a final common pathway of multicellular inflammation, enhanced bronchial responsiveness, and airflow obstruction is a likely consequence. This review discusses the most common causes of asthma exacerbations with a focus on their microbiology and immunopathogenesis. Through an understanding of underlying causes of asthma exacerbations, treatments with increased effectiveness may be developed, and it is these future developments that may directly influence the morbidity and mortality of the disease.

Relationship between climate, pollen concentrations of Ambrosia and medical consultations for allergic rhinitis in Montreal, 1994-2002

The aim of this study is to evaluate the influence of meteorological factors on Ambrosia pollen concentrations and its impact on medical consultations for allergic rhinitis of residents from various socio-economic levels in Montréal (Québec, Canada) between 1994 and 2002. The study was conducted to recognize the sensitivity of pollen productivity to daily climate variability in order to estimate the consequences on human health vulnerability in the context of global climate change. Information related to medical consultations for allergic rhinitis due to pollen comes from the Quebec Health Insurance Board (Régie de l'assurance-maladie du Québec). Ambrosia pollen concentration was measured by the Aerobiology Research Laboratories (Nepean, Ontario). Daily temperature (maximum, minimum, and mean) and precipitation data were obtained from the Meteorological Service of Canada. Socio-economic data come from the 1996 and 2001 census data of Statistics Canada. Between 1994 and 2002, during the Ambrosia pollen season, 7667 consultations for allergic rhinitis due to pollen were recorded. We found a significant association between the number of medical consultations and pollen levels. Significant associations were detected for over-consultation the day of exposure, 1, 2, 3 and 5 days after exposure to high levels of pollen. The consultation rate is higher from low-income residents (3.10 consultations per 10,000 inhabitants) than for high-income (1.65 consultations per 10,000 inhabitants). Considering the demonstrated impact of pollen levels on health, it has become critical to ensure adequate monitoring of Ambrosia and its meteorological sensivity in the context of the anticipated climate change and its potential consequences on human health.

Comparison of enzyme immunoassay-based assays for environmental Alternaria alternata

BACKGROUND

Alternaria alternata-derived allergenic materials are causes of human disease. Several immunoassays exist to quantify these materials.

OBJECTIVE

To compare methods for evaluating Alternaria content.

METHODS

Four methods, including 1 monoclonal antibody (MAb)-based assay specific for recombinant Alt a 1, 1 MAb-based assay for chromatographically purified Alt a 1, 1 polyclonal antibody (PAb)-based assay for chromatographically purified Alt a 1, and 1 PAb-based assay for whole Alternaria extract, were evaluated. Environmental samples collected as part of the National Survey of Lead and Allergens in Housing were examined. Alternaria spore counts were determined in dust by observation.

RESULTS

The MAb-based assay for recombinant Alt a 1 detected Alternaria in few samples (25%); the PAb-based assay for whole Alternaria proteins detected antigen in 97% of the samples. The PAb- and MAb-based assays for purified Alt a 1 detected antigen in 100% of the samples. There was a significant positive correlation between the 2 assays directed against purified Alt a 1. There was a positive correlation between the PAb-based assay for whole Alternaria and the PAb-based assay for Alt a 1. Nearly all the dust samples contained Alternaria spores, and there was a strong positive correlation between counts and all assays.

CONCLUSION

Because of the multifaceted nature of Alternaria, the disparities between methods for quantifying Alternaria, the cross-reactivity between fungal allergens, and the documented genetic promiscuity of this fungus, enzyme immunoassays using PAbs against a range of Alternaria proteins will probably produce the most reliable estimation of overall Alternaria exposure in house dust.

Efficacy and safety of allergen immunotherapy in children

OBJECTIVE

To determine the efficacy and safety of immunotherapy in children with allergic rhinitis and allergic asthma.

DATA SOURCES

Current Contents database for 1967 to 2005.

STUDY SELECTION

The expert opinion of the author was used to select studies for inclusion in this review.

RESULTS

Meta-analyses have confirmed the clinical effectiveness of allergen immunotherapy in patients with allergic rhinitis and asthma; however, most studies involved immunotherapy with a single allergen. Special considerations of safety regarding immunotherapy in children are also necessary, since fatalities have been reported. Fatal reactions occur primarily in patients with asthma and particularly those whose asthma is not well controlled. There is probably increased risk during the build-up phase and with the first injection from a new vial. Injections at home or in clinics without adequate supervision also constitute an increased risk of a fatal outcome.

CONCLUSIONS

Specific immunotherapy has been demonstrated to have some protective effect against the development of additional sensitivities in the monosensitized child and to reduce the risk of developing asthma in children with allergic rhinitis. Because of the modification of the underlying immune process, the beneficial effects of immunotherapy persist for a long but not yet fully determined period after the cessation of treatment. This persisting effect makes immunotherapy an attractive supplement to symptomatic treatment of children with allergic asthma and allergic rhinitis. The treatment is not without risk, however, especially in the child with asthma, so it should be administered with caution.

The medical effects of mold exposure

Exposure to molds can cause human disease through several well-defined mechanisms. In addition, many new mold-related illnesses have been hypothesized in recent years that remain largely or completely unproved. Concerns about mold exposure and its effects are so common that all health care providers, particularly allergists and immunologists, are frequently faced with issues regarding these real and asserted mold-related illnesses. The purpose of this position paper is to provide a state-of-the-art review of the role that molds are known to play in human disease, including asthma, allergic rhinitis, allergic bronchopulmonary aspergillosis, sinusitis, and hypersensitivity pneumonitis. In addition, other purported mold-related illnesses and the data that currently exist to support them are carefully reviewed, as are the currently available approaches for the evaluation of both patients and the environment.

Efficacy of fexofenadine in the prophylactic control of cat allergen-induced allergic rhinitis

BACKGROUND

To date, it is unknown whether fexofenadine mitigates the worsening of symptoms induced by the cat allergen Felis domesticus allergen 1.

OBJECTIVE

To determine the effects of a single dose of fexofenadine hydrochloride, 180 mg, in preventing and controlling cat allergen-induced allergic rhinitis symptoms using the cat room challenge model.

METHODS

This single-center, randomized, double-blind, placebo-controlled, 2-way crossover study consisted of a screening visit, 1 or 2 qualifying visits, and 2 treatment periods separated by a mean +/- SD washout period of 14 +/- 3 days. Patients were randomized to treatment sequence 1 (placebo followed by fexofenadine) or sequence 2 (fexofenadine followed by placebo). Baseline end points were obtained before study drug administration, and allergen challenges were initiated 1 1/2 hours after dosing. The primary end point was the change from predose baseline in the total symptom score (sum of rhinorrhea, itchy nose/palate/ throat, sneezing, and itchy/watery/red eyes) after 30 minutes of allergen exposure compared with placebo.

RESULTS

Of 211 patients screened, 66 were randomized and 63 completed the study. Mean change in the total symptom score from predose baseline was significantly less with fexofenadine compared with placebo 30 minutes after initiation of the cat allergen challenge (2 hours after dosing) (P = .03). The overall incidence of treatment-emergent adverse events was low and comparable for both groups.

CONCLUSION

Prophylactic treatment with a single dose of fexofenadine hydrochloride, 180 mg, significantly mitigated the worsening of allergic rhinitis symptoms induced by exposure to cat allergen compared with placebo use.

Allergy and infection: understanding their relationship

Sensitization to indoor allergens has long been recognized as a risk factor for asthma and its associated phenotypes. Immunoglobulin E antibody quantification may be used to confirm that a particular sensitization has a role in the development of respiratory symptoms. However, in order to use quantitative information effectively, it is essential to understand the factors that contribute to the deterioration of symptoms and cause exacerbations. One such risk factor is high allergen exposure. Worsening asthma control is also associated with virus infections, in particular rhinovirus infection. Each of these factors in isolation is unlikely to have a major effect on symptoms. However, the combination of respiratory virus infection, allergen sensitization and concurrent high exposure to allergens markedly increases the risk for hospitalization. Further investigation of this synergism could help to understand the mechanisms of asthma exacerbations and lead to the development of strategies for prevention.

IgE antibody quantification and the probability of wheeze in preschool children

BACKGROUND

IgE-mediated sensitization is usually considered a dichotomous variable (either sensitized or not). Quantitative IgE antibody analysis may better predict the expression of wheeze.

OBJECTIVE

Within the context of a population-based birth cohort, we investigated the association among wheeze, lung function, and specific IgE antibody levels.

METHODS

Children (n = 521) were followed to age 5 years with repeated questionnaires, skin testing, and measurement of lung function (specific airway resistance) and specific serum IgE (ImmunoCAP).

RESULTS

Using specific IgE as a continuous variable, the risk of current wheeze increased significantly with increasing IgE to mite, cat, and dog (P < .0001). When IgE levels to these 3 allergens were summed, the probability of current wheeze increased 1.33-fold (95% CI, 1.21-1.47; P < .0001) per logarithmic unit increase, corresponding to an odds ratio of 3.1 at 10 and 4.25 at 30 kU(A)/L (kilo units of Allergen per liter). Similarly, increasing sum of mite-specific, cat-specific, and dog-specific IgE was associated with reduced lung function (P = .004). Among sensitized children (n = 184), the sum of mite, cat, and dog IgE was the strongest associate of current wheeze (odds ratio, 1.28; 95% CI, 1.13-1.46; P < .001), corresponding to an odds ratio of 2.56 at 10 and 3.32 at 30 kU(A)/L. There was no association between current wheeze and the size of skin test wheal. Furthermore, the sum of IgE to mite, cat, and dog at age 3 years increased the risk of persistent wheeze by age 5 years (2.15-fold/logarithmic unit increase in the specific IgE).

CONCLUSION

IgE-mediated sensitization is not an all or nothing phenomenon. The probability of wheeze and reduced lung function increases with increasing specific IgE antibody levels.

Sensitization to common indoor allergens and its association with allergic diseases in Thai female high-school students

Allergic sensitization is generally agreed to be an important risk factor for allergic diseases. It has been demonstrated in most of the children attending allergy clinics in Thailand but has never been studied in Thai general populations. The objectives were (i) to describe the prevalence of sensitization to common indoor allergens in Thai female-high-school students and (ii) to evaluate the association of allergic sensitization to allergic diseases in these students. cross-sectional analytic study was designed. Seven hundred and six schoolgirls were enrolled during May-June 2002. Written ISAAC questionnaires were completed by the students and skin prick tests were performed in 344 (48.7%) students with a battery of seven common allergens including Dermatophagoides pteronyssinus, Dermatophagoides farinae, American cockroach, Cat, Cladosporium, Penicillium, and Aspergillus. Positive test was defined as a mean wheal diameter of at least 3 mm at the 15 min reading. The adjusted odds ratios (OR) and 95% confidence intervals (CI) were obtained from multiple regression analysis for the independent effect of sensitization to each allergen on allergic diseases. A total of 154 (44.8%) students had evidence of allergic sensitization on skin prick tests. The prevalence rates of sensitization to various groups of allergens were as follows; mites 43.0%, cockroach 12.8%, cat 4.1%, and molds 1.2%. The independent effect of allergic sensitization on allergic diseases was observed only in mite sensitization on nose problem (OR = 1.73, CI = 1.07-2.78 for nose problem ever and OR = 1.85, CI = 1.13-3.02 for nose problem in 12 months). The risk of nose problem was also increased with the number of positive reactions.

CONCLUSION

We found that sensitization to the four common allergen groups were weakly associated with the presence of allergic diseases in Thai schoolgirls. This confirms the observation that the development of allergic diseases is not solely attributable to allergic sensitization.

Seasonal and perennial allergic rhinitis: is this classification adherent to real life?

BACKGROUND

Allergic rhinitis is traditionally subdivided into seasonal (SAR) and perennial (PAR), although the new definitions of persistent and intermittent were recently proposed. We assessed the validity of the traditional classification in a large group of subjects suffering from allergic rhinitis alone.

METHODS

Young males referred to a Navy Military Hospital for routine fitness visit, and reporting symptoms of rhinitis alone were selected. According to the sensitization they were subdivided into (i) sensitized to pollens only (seasonal, SAR), (ii) to perennial allergens only (perennial, PAR) and (iii) to both (mixed, MAR). Spirometry, methacholine challenge, severity and characteristics of symptoms were assessed in all participants.

RESULTS

Of 19 325 subjects, 2347 had allergic rhinitis. Seventy-two percent of the subjects had MAR, 17% SAR and 11% PAR. Ocular involvement and irritative symptoms were more frequent in SAR (P < 0.03), whereas obstruction was predominant in PAR (P < 0.01). Nasal symptoms varied according to the period of the year in SAR (P < 0.01) and PAR (P < 0.03). An overt bronchial obstruction was detected in 12% of PAR patients, in 7.8% of MAR, and in 4.2% of SAR. forced expiratory volume/1 s was significantly lower during season in SAR patients only (P < 0.05). The FEF25-75 was impaired in 22.5% MAR patients, 21% PAR, and 14% SAR, with a seasonal change in SAR (P < 0.05) and PAR (P < 0.001). Bronchial hyperreactivity was present in 82.2% of PAR, 73.6% of MAR, and 53.5% of SAR, with a seasonal change in SAR (P < 0.001) and MAR (P < 0.05).

CONCLUSIONS

This study provides evidence that up to 80% of allergic rhinitics have a mixed form, and SAR and PAR definitions are poorly adherent to real life. Lung involvement is frequent in patients reporting nose symptoms alone.

Variation in total and specific IgE: effects of ethnicity and socioeconomic status

BACKGROUND

Asthma is common in minority and disadvantaged populations, whereas atopic disorders other than asthma appear to be less prevalent. It is unclear whether the same holds true for objective markers of sensitization.

OBJECTIVE

To determine the association of asthma, atopic disorders, and specific sensitization with race and socioeconomic factors.

METHODS

We analyzed total and specific IgE among 882 women (577 white, 169 black, and 136 Hispanic) who delivered a child at a large tertiary hospital in Boston, Mass, and who were screened for participation in a family and birth cohort study. Race/ethnicity and other characteristics were obtained from screening questionnaires. Addresses were geocoded, and 3 census-based geographic area socioeconomic variables were derived from block group information from the 1990 US Census.

RESULTS

Black and Hispanic women were more likely to come from areas with low socioeconomic indicators and were more likely to have asthma than white women. However, these women were less likely to have hay fever and eczema than their white counterparts. Compared with white women, black women had higher mean total IgE levels; had greater proportions of sensitization to indoor, outdoor, and fungal allergens; and were more than twice as likely to be sensitized to > or =3 aeroallergens.

CONCLUSION

The racial/ethnic disparities in atopic disorders may represent either underdiagnosis or underreporting and suggest that allergy testing may be underused in some populations. Differences in total IgE levels and specific allergen sensitization are likely a result of the complex interplay between exposures associated with socioeconomic disadvantage.

Health effects of indoor fungi

OBJECTIVE

To review the nontoxic harmful effects that poor indoor air quality caused by fungi can have on health.

DATA SOURCES

We searched PubMed for publications related to the various topics discussed in this review, and we relied on our knowledge of the field.

STUDY SELECTION

Where more than one publication was relevant, we attempted to identify a consensus of the reports and cited the most relevant articles. Priority was given to randomized controlled trials and expert reports when available, although much of the information herein relates to laboratory research.

RESULTS

Actively growing fungal colonies can release volatile substances that have an unpleasant smell, leading to psychological responses in the occupants such as fatigue and nausea. Symptoms that are likely caused by indoor fungi include respiratory complaints that involve the nose and lungs, eye symptoms, and mucous membrane irritation. These adverse effects can occur by a variety of mechanisms, including IgE-mediated hypersensitivity, fungal infection, irritant reaction to spores or fungal metabolites, and possibly toxic reaction to mycotoxins.

CONCLUSIONS

Reduced fungal exposure can reasonably be expected to improve health. Removal of moisture from the indoors and proper maintenance of air filters can aid in prevention and elimination of fungi from the home environment. Small areas of present contamination can be cleaned with a dilute bleach solution, which kills viable colonies and removes their mycelia. If fungal contamination is not addressed early, substantial damage can occur, requiring professional remediation. Above all, the individual should not panic at the first sight of fungi growing in the home. Regular inspection and cleaning can prevent many fungus-related problems.

Correlation between inhalant allergen-specific IgE and pulmonary function in children with asthma

Sensitization to aeroallergens is associated with diminished lung function in adults. Little has been studied on the relationship between the inhalant allergen-specific IgE and pulmonary function in asthmatic children. This study was focused on four major inhalant allergens found in Korea, including Dermatophagoides pteronyssinus (Der p.), Dermatophagoides farinae (Der f.), and Alternaria- and German cockroach-specific IgEs, with evaluation of pulmonary function in relation to the amount of allergens. The parents or legal guardians of participants enrolled in this study gave informed consent. Fifty-five asthmatic patients and 48 nonasthmatic children were included. The amounts of specific IgE for the four specified inhalant allergens were determined by employing the CAP system FEIA. Forced expiratory volume in 1 sec (FEV(1))/forced vital capacity (FVC), FEV(1), and forced expiratory flow between 25% and 75% of FVC (FEF(25-75)) of subjects were evaluated through pulmonary function tests. In the asthmatic group, FEV(1), FEV(1)/FVC, and FEF(25-75) were significantly reduced (P < 0.05): reduction in FEV(1) (r = -0.44) and FEF(25-75) (r = -0.33) in association with the Der f.-specific allergen, and reduction in FEV(1) (r = -0.37) and FEF(25-75) (r = -0.34) in association with the Der p.-specific allergen, were observed. However, there was no significant correlation with German cockroach and Alternaria allergen. In the control group, no significant correlation was detectable between the allergen-specific IgE titers and the results of pulmonary function tests. In asthmatic patients, Der p.- and Der f.-specific IgEs, and not German cockroach and Alternaria, seem to play a considerable role in reduced pulmonary function among asthmatic children.

Allergic rhinitis in children : diagnosis and management strategies

The incidence of allergic rhinitis has been increasing for the last few decades, in keeping with the rising incidence of atopy worldwide. Allergic rhinitis has a prevalence of up to 40% in children, although it frequently goes unrecognized and untreated. This can have enormous negative consequences, particularly in children, since it is associated with numerous complications and comorbidities that have a significant health impact on quality of life. In fact, allergic rhinitis is considered to be a risk factor for asthma. There are numerous signs of allergic rhinitis, particularly in children, that can alert an observant clinician to its presence. Children with severe allergic rhinitis often have facial manifestations of itching and obstructed breathing, including a gaping mouth, chapped lips, evidence of sleep deprivation, a long face, dental malloclusions, and the allergic shiner, allergic salute, or allergic crease. The medical history is extremely important as it can reveal information regarding a family history of atopy and the progression of atopy in the child. It is also important to identify the specific triggers of allergic rhinitis, because one of the keys to successful management is the avoidance of triggers. A tripartite treatment strategy that embraces environmental control, immunotherapy, and pharmacologic treatment is the most comprehensive approach. Immunotherapy has come to be viewed as potentially prophylactic, capable of altering the course of allergic rhinitis. The most recent guidelines for the management of allergic rhinitis issued by the WHO recommend a tiered approach that integrates diagnosis and treatment, in which allergic rhinitis is subclassified both by frequency, as either intermittent or persistent, and by severity, as either mild or moderate to severe. Oral or topical antihistamines and intranasal corticosteroids are the mainstay of pharmacologic therapy for allergic rhinitis, depending upon its severity, and several agents have been approved for use in children aged 5 years old and younger.

Dynamic changes in sensitization to specific aeroallergens in children raised in a desert environment

BACKGROUND

Allergen skin test reactivity and total serum IgE are objective measures used to characterize and help diagnose allergic diseases. Cross-sectional studies have shown that overall aeroallergen skin test reactivity increases throughout childhood. However, little attention has been paid to whether individual aeroallergen remittance occurs, which could distort or mask relationships to disease.

OBJECTIVE

To access the incidence and remittance of skin test reactions to individual allergens in children aged 6-11 years.

METHODS

Longitudinal sensitization to six aeroallergens and total IgE were assessed in 828 children raised in the semi-arid US southwest at ages 6 and 11 years.

RESULTS

New sensitization (to any allergen) between 6 and 11 years occurred in 30.2% of children compared with 39.7% before age 6 years. The rate of complete remittance from positive to negative between ages 6 and 11 years was 8.2%, and total IgE at age 6 years was not predictive. Remittance rates for individual allergens were high and variable (19-49%). The perennial allergens Bermuda and Alternaria were early sensitizers and had low remittance rates. Early sensitization to the four seasonal allergens was less common and more subject to remittance with the bulk of sensitization occurring between 6 and 11 years.

CONCLUSION

This study shows that sensitization to individual aeroallergens in childhood is dynamic and indicates the limitation of single point assessment of skin test reactivity.

Dog allergen (Can f 1) and cat allergen (Fel d 1) in US homes: results from the National Survey of Lead and Allergens in Housing

BACKGROUND

Exposures to dog and cat allergens are believed to play important roles in the etiology of asthma; however, the levels of these allergens have never been assessed in a representative sample of US homes.

OBJECTIVE

The objective of this study was to estimate and characterize exposures to Can f 1 (dog allergen) and Fel d 1 (cat allergen) in US homes.

METHODS

Data were obtained from the National Survey of Lead and Allergens in Housing, a nationally representative survey of 831 US homes. Vacuumed-collected dust samples from the bed, bedroom floor, living room floor, and living room sofa were analyzed for concentrations of Can f 1 and Fel d 1 (micrograms of allergen per gram of dust).

RESULTS

Although a dog or cat had lived in only 49.1% of homes in the previous 6 months, Can f 1 and Fel d 1 were detected in 100% and 99.9% of homes, respectively. Averaged over the sampled sites, geometric mean concentrations (microg/g) were 4.69 for Can f 1 and 4.73 for Fel d 1. Among homes with an indoor dog and cat, respectively, geometric mean concentrations were 69 for Can f 1 and 200 for Fel d 1. Among homes without the indoor pet, geometric mean concentrations were above 1.0. The independent predictors of elevated concentrations in homes without pets were all demographic variables that were also linked to a higher prevalence of pet ownership.

CONCLUSIONS

Can f 1 and Fel d 1 are universally present in US homes. Levels that have been associated with an increased risk of allergic sensitization were found even in homes without pets. Because of the transportability of these allergens on clothing, elevated levels in homes without pets, particularly among demographic groups in which pet ownership is more prevalent, implicate the community as an important source of these pet allergens.

Lower prevalence of reported asthma in adolescents with symptoms of rhinitis that received neonatal BCG

BACKGROUND

BCG is a vaccine used against tuberculosis and leprosy and is an immunostimulant that primes T(H)1 lymphocytes to produce cytokines that antagonize atopy both in animal models and in man. Considering that atopy is the main risk factor for asthma, one can hypothesize that vaccination inducing T(H)1 responses, such as BCG, can be protective against asthma.

METHODS

OBJECTIVE

To estimate the association between neonatal BCG vaccination and prevalence of asthma among adolescents.

STUDY DESIGN

Cross-sectional study with schoolchildren aged 12-16 years. The presence of a scar compatible with BCG was used as a surrogate of neonatal vaccination. A self administered structured questionnaire was prepared based on that used by the International Study of Asthma and Allergies in Childhood. The prevalence of asthma was categorized according to the report of lifetime wheeze, lifetime asthma, lifetime asthma among those referring allergy and among those referring allergy and sneezing.

RESULTS

Neonatal BCG vaccination was not associated with the overall prevalence of reported wheezing or asthma. However, in the subgroup reporting current allergy and sneezing, neonatal BCG was associated with a 37% reduction of prevalence of lifetime asthma.

CONCLUSIONS

In the population we surveyed, neonatal BCG scar was associated with a reduction in the risk of asthma only in individuals with a past history suggestive of allergic rhinitis.

Knowledge of skin test results among parents of asthmatic children

BACKGROUND

The control of asthma in children depends upon several factors, among which is the ability of parents to minimize the exposure of their children to specific allergens. If parents are ill-informed of the specific allergen sensitivity of their children, they may be unable to take the necessary steps to minimize exposure.

OBJECTIVES

This study seeks to determine the ability of parents to recall accurately the skin test results for their children. Parents were low income, multicultural, urban residents.

METHODS

One hundred eligible children with persistent asthma, between 6 and 14 years old, who were skin test positive to dust mite or cockroach allergen, were recruited from a mobile asthma clinic in Los Angeles. Caretakers were interviewed in English or Spanish. From skin test results, sensitivity and specificity of parental recall of test results were computed. The sensitivity and specificity were further stratified on demographic and exposure characteristics.

RESULTS

The sensitivity was lowest for dogs (65%), but higher for all other allergens: cat 93%, roach 91%, dust mites 88%, and mold 81%. The range of specificity was from 40% to 83%. Thus, parents were more aware of positive than of negative test results. Stratification did not appreciably change the sensitivity or specificity results.

CONCLUSIONS

We conclude that the sensitivity and specificity of parental response concerning skin test results is high regardless of cultural, demographic, or exposure levels of the child.

Association between nasal and bronchial symptoms in subjects with persistent allergic rhinitis

BACKGROUND

The association between nasal and bronchial symptoms, and the course of bronchial responsiveness and airway inflammation in house dust mite sensitive persistent rhinitis over a prolonged time period has not been thoroughly explored.

OBJECTIVE

To determine if nasal symptoms were associated with bronchial symptoms in persistent rhinitic subjects, and to assess their bronchial responsiveness and airway inflammation in comparison to nonrhinitic, nonatopic controls. The additional impact of pollen sensitivity on the lower airways in rhinitic subjects was also addressed.

METHODS

Rhinitics and controls answered telephone symptom questionnaires once every 2 weeks for 1 year. Every 3 months, exhaled nitric oxide (eNO) and bronchial responsiveness to histamine were measured.

RESULTS

Thirty-seven rhinitics and 19 controls completed the study. High nasal symptom scores in rhinitic subjects were associated with bronchial symptoms (OR = 1.7, 95% CI 1.2-2.5). Bronchial hyper-responsiveness was present in 32.4% of rhinitic subjects on at least one clinical visit during the year. Pollen allergy caused seasonal variation in eNO (P = 0.03).

CONCLUSION

In persistent rhinitic subjects, high nasal symptom scores were associated with bronchial symptoms, and many subjects experienced bronchial hyper-responsiveness during the year. Persistent rhinitic subjects were more at risk than healthy adults of bronchial symptoms and airway inflammation, which are likely risk factors for asthma.

Association of recurrent wheezing with sensitivity to cockroach allergen in inner-city children

BACKGROUND

There are numerous data that show a strong relationship between early exposure and sensitization to indoor allergens and the development of asthma and persistent wheezing in children. Most studies, however, have only examined the prevalence of allergy in children who have been identified as having asthma.

OBJECTIVE

To assess the prevalence of positive skin test results to common inhaled allergens and possible association with wheezing in inner-city children being seen in a general pediatric clinic.

METHODS

Skin testing to common aeroallergens was performed by the prick-puncture method. Demographic and clinical data were collected.

RESULTS

Seventy-five children aged 2 months to 10 years were evaluated. A total of 37% of the children had a positive skin test result to at least one allergen; 29% of the children were sensitive to dust mite, 15% to cockroach, 9% to cat, 7% to mold, 4% to grass, 3% to ragweed, and 1% to dog. Seven (64%) of 11 children with positive skin test results to cockroach had a history of wheezing compared with 21 (33%) of 64 with negative skin test results to cockroach (P = .05).

CONCLUSIONS

Our results indicate that in a population of inner-city children not previously identified as atopic, more than a third showed sensitivity to at least one allergen. Although dust mite was the most common allergen to which the children were sensitized, cockroach sensitivity was the only allergen that correlated significantly with previous episodes of wheezing.

Ethnicity and skin test reactivity to aeroallergens among asthmatic children in Connecticut

OBJECTIVES

To examine the relationship between ethnicity and sensitization to allergens among children with asthma living in urban and suburban areas of Connecticut.

STUDY DESIGN

Cross-sectional study.

STUDY POPULATION

A total of 791 children with mild-to-severe asthma who received their medical care in the city of Hartford.

RESULTS

Puerto Rican ethnicity was associated with skin test reactivity (STR) to cockroach (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.7 to 6.4), STR to dust mite (OR, 1.7; 95% CI, 1.2 to 2.4), STR to mixed grass pollen (OR, 1.7; 95% CI, 1.1 to 2.7), and STR to mugwort/sage (OR, 2.4; 95% CI, 1.4 to 4.1). African-American ethnicity was associated with STR to four outdoor allergens (ie, mixed tree pollen [OR, 2.3; 95% CI, 1.3 to 3.9], mixed grass pollen [OR, 2.7; 95% CI, 1.6 to 4.8], mugwort/sage [OR, 3.1; 95% CI, 1.6 to 6.0], and ragweed [OR, 2.1; 95% CI, 1.2 to 3.8]). Among all children, STR to outdoor allergens was strongly associated with the extent of allergen sensitization. As an example, children sensitized to mixed grass pollen had 34.7 times higher odds of having at least four positive skin tests to other allergens than nonsensitized children (95% CI for OR, 15.6 to 77.0).

CONCLUSIONS

Our findings suggest that Puerto Rican ethnicity is associated with an increased risk of sensitization to indoor and outdoor allergens among children with asthma, and that allergy skin testing should be performed more often as part of the management of asthma in African-American children and in Puerto Rican children in the United States.

Animal danders

Animals release proteins into their surroundings through secretions, as excretions, or as dander. The quantity of dander that is dispersed by cats, dogs, or humans is sufficient to supply food for dust mites and to supply easily measurable quantities of proteins in dust. Fel d 1, Can f 1, and human IgA or IgG can be found in microgram quantities in dust samples. Allergens also can accumulate from the urine of wild or pet rodents. For cats and dogs, the accumulation of dander particles is not related to the cleanliness of the animals. All animals, including humans, provide a fully adequate supply of organic material for bacterial growth in a carpet, provided conditions are sufficiently humid. The authors' preliminary results in Virginia do not find a significant difference in endotoxin between homes with or without animals. The likely explanation for the nonallergic IgG and IgG4 response to cat, dog, or rat allergens is high exposure to proteins from these animals. If the highest levels of cat allergen in a home can result in immunologic tolerance, it is unlikely that primary avoidance would be successful at reducing exposure. The data showing that 80% of Swedish children with cat allergies never had lived with a cat imply that the concentrations of cat allergen in schools or in houses without a cat are sufficient to cause sensitization. Primary prevention would be possible only on a community basis, which is unlikely to occur. Sensitization to cat, rat, dog, or mouse allergens consistently is associated with asthma. In symptomatic children with positive skin test results, there is a strong case for allergen avoidance and a clear need for controlled trials. Controlled trials of avoidance should include houses without cats and schools. Controlling exposure to cat allergens with the cat in situ requires aggressive measures, such as removing reservoirs, washing the cat, and air cleaning. Many allergic or symptomatic children who live with a cat do not have positive skin test results or positive IgE antibodies to cats. Avoidance measures related to animals should be recommended only for individuals with positive skin test results. Increasing evidence shows that exposure to cats, dogs, rats, and other animals can induce a form of immunologic tolerance without causing allergic disease, and it is important to understand why this change occurs with dander allergens rather than with all allergens. The most probable explanations are related to the form and quantity of airborne allergens.

Clinical relevance of spore and pollen counts

Many people with allergies monitor daily pollen and spore counts with the belief that they can act on that information to improve their health. Because many factors can affect personal exposure, the value of community-wide counts for an individual is questionable. These factors include the presence of local pollen and spore sources, diurnal variations, weather effects, air pollution, and a particle-free bioaerosol. To take advantage of bioparticulate counts, the public needs to be informed about their meaning and factors that can influence personal exposure.