Number Of Positive Skin Prick Tests Research Articles

Allergies and Exercise-Induced Bronchoconstriction in a Youth Academy and Reserve Professional Soccer Team.

A high prevalence of respiratory allergies and exercise-induced bronchoconstriction (EIB) has been reported among endurance athletes. This study was designed to analyze the frequency of sensitization to respiratory allergens and EIB in young soccer players. Prospective cohort design. Youth academy and reserve professional soccer team during the seasons 2012 to 2013 and 2013 to 2014. Eighty-five soccer players (mean age: 20 ± 4 years) participated. Players underwent skin prick tests (SPTs) during the seasons 2012 to 2013 and 2013 to 2014. Spirometry and a eucapnic voluntary hyperpnea test were performed on soccer players during the first season 2012 to 2013 (n = 51) to detect EIB. Two self-administered questionnaires on respiratory history and allergic symptoms (European Community Respiratory Health Survey and Allergy Questionnaire for Athletes) were also distributed during both seasons (n = 59). The number of positive SPTs, exercise-induced respiratory symptoms, presence of asthma, airway obstruction, and EIB. Forty-nine percent of players were sensitized to at least one respiratory allergen, 33% reported an allergic disease, 1 player presented airway obstruction at rest, and 16% presented EIB. Factors predictive of EIB were self-reported exercise-induced symptoms and sensitization to at least 5 allergens. Questioning players about exercise-induced respiratory symptoms and allergies as well as spirometry at the time of the inclusion medical checkup would improve management of respiratory health of soccer players and would constitute inexpensive preliminary screening to select players requiring indirect bronchial provocation test or SPTs. This study showed that despite low frequencies, EIB and allergies are underdiagnosed and undertreated in young soccer players.

Airway hyper-responsiveness to mannitol provides a good evaluation of atopy in childhood asthma.

The relationship between airway hyper-responsiveness (AHR) and atopy has been previously investigated, but there are still some issues to be clarified. The aim of this study was to assess the link between AHR and mannitol and atopy in asthmatic children. We evaluated 44 children with asthma, aged 6-16 years of age, using skin prick tests (SPTs), serum total and specific immunoglobulin E (IgE) levels and the mannitol challenge test (MCT). We found a good correlation between AHR to mannitol and specific IgE against Dermatophagoides pteronissinus (r = -0.66, p < 0.001) and a weak correlation with specific IgE against dog dander (r = -0.33, p = 0.01) and Aspergillus fumigatus (r = -0.23, p = 0.02). Furthermore, we found a weak correlation between AHR to mannitol and serum total IgE (r = -0.30; p = 0.03), the sum of specific IgE to aeroallergens (r = -0.37, p = 0.01) and the number of positive SPTs (r = -0.31, p = 0.02). Measuring AHR with MCT might provide an accurate evaluation of the degree of atopy in children. The patients with a higher degree of atopy were significantly more reactive to mannitol. In clinical practice, these results indicate that children with asthma who are more atopic may require more intensive treatment strategies to reduce AHR.

Predicting allergic disease at age four using an atopy predisposition score at age two: the application of item response theory

When defining allergic outcomes in epidemiology studies, results of the skin prick test (SPT) panel are often dichotomized as positive/negative or categorized based on the number of positive responses. Item response theory (IRT) models, however, may prove to be a better alternative with the ability to generate scores that account for both type and number of positive SPTs. IRT was applied to SPT responses administered to 537 children at age two to determine predictability of allergic disease at age four. The children received SPTs to 15 aeroallergens and two foods. Atopy predisposition scores were obtained from the IRT model using the posterior distribution of the latent trait, atopy. These scores were used to predict persistent wheeze, rhino-conjunctivitis, and eczema at age four. Results were compared to the dichotomized and categorical (positive to ≥2, positive to one, vs. negative to all allergens) SPT variables. At age two, 39% of children had at least one positive SPT. All three allergic disease outcomes were significantly associated with IRT atopy scores: persistent wheeze odds ratio (OR) = 1.7 (95% confidence interval (CI): 1.2, 2.3); rhino-conjunctivitis OR = 1.7 (95% CI: 1.2, 2.3); eczema OR = 1.6 (95% CI: 1.2, 2.3). In contrast, rhino-conjunctivitis was the only outcome significantly associated with the dichotomized SPT variable with an OR = 1.9 (95% CI: 1.2, 3.0). For the categorical SPT variable, all three allergic symptoms were significantly associated with positive to ≥2 allergens compared to negative to all, but no difference was observed between those with positive to one compared to negative to all. The IRT model proved to be an informative methodology to assess the predictability of early SPT responses and identify the allergens most associated with atopy predisposition.

Bronchial Hyperresponsiveness in Preschool Children with Allergic Rhinitis

Nonasthmatic subjects with allergic rhinitis often have bronchial hyperresponsiveness (BHR), characteristic of asthma. The presence and degree of atopy is suggested to be important for BHR in patients with asthma. We aimed to assess BHR to methacholine (direct stimulus) and to adenosine 5'-monophosphate (AMP; indirect stimulus) in preschool children with allergic rhinitis and to investigate their relationship with the degree of atopy. Methacholine and AMP bronchial challenges were performed in preschool children with allergic rhinitis (n = 96), using a modified auscultation method. The end point concentration, resulting in audible wheezing and/or oxygen desaturation, was determined for each challenge. The degree of atopy was assessed using serum total IgE levels, the number of positive skin-prick tests, and atopic scores (sum of graded wheal size). BHR to methacholine (end point concentration, ≤8 mg/mL) and to AMP (end point concentration, ≤200 mg/mL) was observed in 32 (33.3%) and 26 (27.1%) subjects, respectively. No significant relationship was observed between BHR to methacholine and any atopy parameter. In contrast, the atopic scores were higher in the AMP-BHR(+) group compared with the AMP-BHR(-) group, and a significant association was found between the degree of atopic scores and the frequency of BHR to AMP (score for trend, p = 0.006). Such a relationship was not observed for serum total IgE levels and the number of positive SPTs. BHR to methacholine and BHR to AMP were detected in a significant proportion of preschool children with allergic rhinitis. The degree of atopy in terms of atopic scores seems to be an important factor for BHR to AMP but not for BHR to methacholine.

Associations between asthma and bronchial hyper-responsiveness with allergy and atopy phenotypes in urban black South African teenagers.

To determine asthma and allergy phenotypes in unselected urban black teenagers and to associate bronchial hyper-responsiveness (BHR) with asthma, other atopic diseases and allergen sensitisation. This was a cross-sectional study of 211 urban high-school black children of Xhosa ethnicity. Modified ISAAC questionnaires regarding asthma, eczema and rhinitis were administered. BHR was assessed by methacholine challenge using hand-held nebulisers. Skinprick tests (SPTs) were performed for 8 aeroallergens and 4 food allergens. Asthma was reported in 9%, and 16 % demonstrated BHR. Rhinitis was reported in 48% and eczema in 19%. Asthma was strongly associated with BHR. Asthma was associated with eczema whereas BHR was associated with rhinitis. SPTs were positive in 34% of subjects, aeroallergens in 32%, and food allergens in 5%. The most common sensitivities were to house dust mites (HDM) and German cockroach. BHR was associated with sensitivity to any aeroallergen, cat, HDM, cockroach and bermuda grass. The number of positive SPTs was associated with asthma and BHR. With each level of SPT positivity, there was 40% increased prevalence of asthma and 70% increased prevalence of BHR. The rate of allergen sensitisation in subjects with BHR (72%) was much higher than those without BHR (28%); house dust mite sensitivity was 69% in subjects with BHR and 18% in those without. These are the highest rates of allergen sensitisation in subjects with BHR documented in an African setting and the widest difference in sensitisation rates between subjects with and without BHR.

Methacholine and adenosine 5′‐monophosphate (AMP) responsiveness, and the presence and degree of atopy in children with asthma

The relationship between atopy and bronchial hyperresponsiveness (BHR), both key features of asthma, remains to be clarified. BHR is commonly evaluated by bronchial challenges using direct and indirect stimuli. The aim of this study was to investigate the degree of BHR to methacholine (direct stimulus) and adenosine 5'-monophosphate (AMP) (indirect stimulus) according to the presence and degree of atopy in children with asthma. We performed a retrospective analysis of data from 120 children presenting with a diagnosis of asthma. These children were characterized by skin-prick tests (SPTs), spirometry and bronchial challenges with methacholine and AMP. Atopy was defined by at least one positive reaction to SPTs, and its degree was measured using serum total IgE levels, number of positive SPTs and atopic scores (sum of graded wheal size). A provocative concentration causing a 20% decline in FEV(1) (PC(20) ) was determined for each challenge. Patients with atopy(n=94) had a significantly lower AMP PC(20) than non-atopic patients (n=26), whereas methacholine PC(20) was not different between the two groups. Among the patients with atopy, there was no association between methacholine PC(20) and any atopy parameter. In contrast, a significant association was found between AMP PC(20) and the degree of atopy reflected in serum total IgE, number of positive SPTs and atopic scores (anova trend test, p=0.002, 0.001, 0.003, respectively). AMP responsiveness was associated with the presence and degree of atopy, whereas such a relationship was not observed for methacholine responsiveness. These findings suggest that atopic status may be better reflected by bronchial responsiveness assessed by AMP than by methacholine.

Association between short sleep duration and the risk of sensitization to food and aero allergens in rural Chinese adolescents

Both long and short sleep duration have been associated with obesity, cardiovascular disease, and diabetes. However, there have been no previous studies investigating the potential relationship between altered sleep duration and allergen sensitization. To explore the association between sleep duration and sensitization to food and aeroallergens. This study includes 1534 rural Chinese adolescent twins aged 12-21 years who completed standard sleep questionnaires and skin prick tests (SPTs) to nine food and five aeroallergens. Total sleep time was defined as the interval from bedtime to wake-up time minus sleep latency. Sensitization was defined as having at least one positive SPT. Compared with individuals with the highest (third) tertile of sleep duration, those who slept less were more likely to be sensitized to any food allergen with odds ratios (ORs) of 1.9 [95% confidence interval (CI): 1.3-2.7] and 1.4 (95% CI: 1.0-1.9) for the first and second tertiles (trend test P(trend)=3×10(-4)), respectively. The corresponding ORs for sensitization to any aeroallergen were 1.5 (95% CI: 1.1-2.0) and 1.3 (95% CI: 1.0-1.7) (P(trend)=8×10(-3)). These associations were independent of percent body fat. In addition, we observed a significant dose-response association between the number of positive SPTs and percentage of shortest sleep duration (first tertile) (P(trend)=1×10(-3)). In this sample of relatively lean rural Chinese adolescents, we found that short sleep duration was associated with increasing risk of sensitization to food and aeroallergens, independent of percent body fat. Longitudinal studies are needed to further determine the temporal and causal relationships. If short sleep duration indeed is one of the risk factors for allergic sensitization, the global burden of allergic diseases could be dramatically reduced by providing appropriate guidance on sleep duration for youth.

Bronchial hyperresponsiveness to methacholine and adenosine 5′-monophosphate, and the presence and degree of atopy in young children with asthma

Bronchial hyperresponsiveness (BHR) is a characteristic feature of asthma, and is usually measured by bronchial challenges using direct or indirect stimuli. The relationship between atopy and BHR remains to be clarified, particularly in a population selected for asthma. Furthermore, data for young children are limited, although asthma frequently occurs in early childhood. The aim of this study was to investigate methacholine (direct stimulus) and adenosine 5'-monophosphate (AMP) (indirect stimulus) responsiveness according to the presence and degree of atopy in young children with asthma. A retrospective analysis of data from 122 preschool children (median age [range]: 5.3 years [4.0-6.8]) presenting with the diagnosis of asthma was performed. These children were characterized by skin-prick tests (SPTs) and bronchial challenges with methacholine and AMP, using a modified auscultation method. The end-point concentration, resulting in audible wheezing and/or oxygen desaturation, was determined for each challenge. Atopy was defined by at least one positive reaction to SPTs, and its degree was assessed using serum total IgE levels, number of positive SPTs, and atopic scores (sum of graded weal size). Atopic patients (n=97) had a significantly lower AMP end-point concentration than non-atopic patients (n=25), whereas the methacholine end-point concentration was not different between the two groups. Among the atopic patients, there was no association between the methacholine end-point concentration and any of the atopy parameters. By contrast, a significant association was found between the AMP end-point concentration and the degree of atopy reflected in serum total IgE and atopic scores (χ² test for trend, P=0.001, 0.003, respectively). Young children with atopic asthma had a significantly greater AMP responsiveness than those with non-atopic asthma, whereas methacholine responsiveness was not significantly different between the two groups. The degree of atopy appeared to be an important factor in AMP responsiveness, but not in methacholine responsiveness, and thus might be a marker of airway inflammation in asthma.

Military service-aggravated asthma improves at two-year follow-up

During military service young men (age 19-21 years) are exposed to many predisposing factors for asthma. We aimed to study the short-term prognosis of asthma after the military service. All 216 men with verified asthma in 2004-2005 from the register of the Central Military Hospital were included in the study. A questionnaire was mailed to them in autumn 2007 and the 146 responders (68%) formed the final study population. Asthma severity was evaluated during military service according to the medical records of the subjects and two years later based on the questionnaire using modified GINA guidelines. The results on lung function and allergy tests during military service and asthma history were used as predictors of asthma severity at two-year follow-up. Two groups of asthmatics were identified: those who already had asthma when entering the military service (n=71, 48.6%) and those, who had a new onset of asthma during the service (n=75, 51.4%). Overall asthma was less severe at two-year follow-up than during military service (p=0.036). Both during military service and at two-year follow-up, asthma was milder among the men, who had a new onset of asthma during military service. Atopy (p=0.002), number of positive skin-prick tests (p=0.005) and higher total serum IgE (p=0.001) were significant predictors for persistent asthma at follow-up. Asthma, which had aggravated or started during military service, was significantly less severe two years later. The degree of atopy was a major determinant of the two-year prognosis of asthma after military service.

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Food intolerance and skin prick test in treated and untreated irritable bowel syndrome

To correlate the clinical features of treated and untreated patients with irritable bowel syndrome (IBS) to the results of skin prick test (SPT) for food and inhalant allergens. We recruited 105 subjects to form three different target groups: treated group (n=44) undergoing treatment for IBS, untreated group (n=31) meeting the Rome II criteria without treatment for IBS, control group (n=30) with no IBS symptoms. SPT results were different among the three groups in which SPT was positive in 17 (38.6%) treated patients, in 5 (16.1%) untreated patients and in 1 (3.3%) control (P<0.01). The number of positive SPTs was greater in the IBS group than in the control group (P<0.001). The number of positive food SPTs was higher in the treated IBS group than in the untreated IBS group (P=0.03). Positive food SPT is higher in IBS patients than in controls.

Toll-like receptor 4 polymorphism and severity of atopy in asthmatics.

Endotoxin exposure may have a protective effect against asthma and atopy. An Asp299Gly polymorphism in the Toll-like receptor 4 (TLR4) gene reduces responsiveness to endotoxin. This study determined the effect of TLR4 polymorphism on the risk and severity of asthma and atopy. In all, 336 UK Caucasian families with > or = 2 affected sibs (physician's diagnosis of asthma and current medication use) and 179 Caucasians without asthma or a family history of asthma were genotyped using ARMS-PCR. No association of the TLR4 polymorphism was found with the risk of developing asthma, either in parent-affected sibling trios, or in case-control analyses (P>0.05). In the first affected asthmatic siblings, the atopy severity score (based on size and number of positive skin-prick tests and specific IgE) was higher in those with the Asp/Gly or Gly/Gly genotypes (mean 1.8, s.d. 1.1, n=39) compared to those with the Asp/Asp genotype (mean 1.2, s.d. 1.0, n=279) (P=0.003, t-test). No associations were found with total IgE, FEV(1) % predicted, slope of FEV(1) response to methacholine or asthma severity score (P>0.05). This study confirms the previously observed lack of association of TLR4 polymorphisms with asthma. In contrast, the findings suggest that genetically determined hyporesponsiveness to endotoxin may increase atopy severity.

Fewer allergic respiratory disorders among farmers' children in a closed birth cohort from Sweden

The aim of this study was to investigate the prevalence of respiratory allergy, eczema and atopic sensitization in a closed birth cohort of Swedish schoolchildren, 7-8 yrs of age (n=707), of farmers and nonfarmers on the island of Gotland, in the Baltic Sea. All children were born and raised on the island. The survey comprised a questionnaire on atopic diseases and lifestyle factors. Atopic sensitization was assessed by the skin-prick test (SPT) with 15 standardized allergens. The risk ratio (RR) for ever having asthma and/or allergic rhinoconjunctivitis was significantly lower among children of farmers compared to children of nonfarmers (RR=0.38, confidence interval (CI) 95% 0.19-0.77). SPTs (test rate 92%) showed that 32% of the children had at least one positive test. Although the number of positive SPTs did not differ between the groups, there was a reduced risk among children of farmers for having both respiratory symptoms and sensitization to any International Study on Asthma and Allergy in Childhood allergen (RR=0.28, CI 95% 0.09-0.88). The present indicate that living in a farming population seems to protect against development of respiratory allergic disorders but not against allergic sensitization.

Atopy Influences Exhaled Nitric Oxide Levels in Adult Asthmatics

To examine whether atopy influences exhaled nitric oxide (NO) levels in adults with established asthma. Specialist respiratory unit in a university teaching hospital. Twenty-eight asthmatics (mean FEV(1), 85.7%) receiving short-acting inhaled bronchodilators and a range of inhaled steroids (0 to 4,000 microg/d). Subjects were studied on two occasions, 5 to 7 days apart, between September and March. On the first day, FEV(1), exhaled NO, and histamine challenge were performed. On the second day, exhaled NO, total IgE, and skin-prick testing to six common allergens were conducted. Exhaled NO was measured with the single exhalation method. We found exhaled NO levels to correlate positively with total IgE (r = 0.43, p = 0.02) and number of positive skin-prick tests (p = 0. 002). By contrast, there was no significant correlation between exhaled NO and FEV(1) or the provocative concentration causing a 20% fall in FEV(1). Subanalyses of steroid-treated and steroid-naive patients in this group revealed the same findings. Exhaled NO levels in asthmatics correlate more closely with atopy than with bronchial hyperreactivity and lung function.

Maternal Avoidance of Eggs, Cow's Milk, and Fish During Lactation: Effect on Allergic Manifestations, Skin-Prick Tests, and Specific IgE Antibodies in Children at Age 4 Years

Two matched groups of children with a family history of atopy/allergy were observed from birth. In one group (n = 65) the mothers had a diet free from eggs, cow's milk, and fish during the first 3 months of lactation, whereas the mothers in the other group (n = 50) had a normal diet. Atopic/allergic manifestations, skin-prick tests, and specific IgE antibodies to egg white and cow's milk during the first 18 months of life have been reported previously. At 4 years of age the children underwent a clinical examination, skin-prick tests, and determination of specific IgE antibodies in serum against certain food and inhalant allergens. Both the cumulative incidence and the current prevalence of atopic dermatitis were significantly lower in the group of children whose mothers had adhered to a hypoallergenic diet during lactation, whereas all other atopic manifestations were similar. The number of children with positive skin-prick tests and specific IgE antibodies did not differ significantly, but the number of positive skin-prick tests and specific IgE antibody reactions in serum was significantly lower in the children of mothers adhering to the diet, indicating a milder degree of sensitization in these children.

The Diagnostic Value of Skin-Prick Tests in Dermographic Individuals

Fifty-five patients displaying significant dermographic wheals, who presented with respiratory or food allergy symptoms, were investigated prospectively. Fifty-five additional patients presenting with similar clinical histories as the study group but without dermographism were used as controls. Total serum IgE and skin-prick tests (SPT) to 30 common allergens were performed on all subjects. Specific IgE (RAST) was determined only in those whose history did not correlate with the skin-test results. Allergens that gave a positive reaction were retested with extra care to exert minimal pressure. No statistically significant difference was found in the percentage of positive SPT reactors when comparing dermographic patients and controls (chi 2 test). No significant difference was found when the number of positive SPT (mean values) was compared between dermographic subjects and controls (t-test). However, when the values of mild positive SPT (1+ to 2+) were compared between the two groups, there was a significant difference only on the first performance of SPT in dermographic individuals (P less than 0.05, t-test). Our findings demonstrate that SPT can be reliable even in the presence of dermographism. False positive results are occasionally observed when the reactions are mild, but careful repetition of positive SPT might eliminate this problem.