BACKGROUND: The mean wheal diameter >/= 3 mm is the usual criterion for positive skin prick test (SPT) reaction to dust mites. The study assessed the accuracy of this SPT criterion with respect to specific IgE values of above 0.35 kUA/l (+ sIgE). METHODS: Specific IgE (ImmunoCAP, Pharmacia AB Diagnostics, Uppsala, Sweden) and standard SPT to Dermatophagoides pteronyssinus (DP) and farinae (DF), Lepidoglyphus destructor (LD) and Tyrophagus putrescentiae (TP) (ALK, Hørsholm, Denmark) were performed in a random sample of 457 subjects, of whom 273 men (mean age 35.3 +/- 11.0 years) and 184 women (mean age 37.9 +/- 9.5 years). Statistical analysis was performed using the chi-square test, regression analysis and discriminant analysis. RESULTS: When the mean wheal diameter of >/= 3 mm was considered positive (+ SPT), the correlation between + SPT and + sIgE was 0.47 for DP (P
Positive skin prick test (SPT) reactions to carmine red (E120) have been reported to occur concurrently with reactions to mites. The relationships between positive SPT reactions to carmine, carmine allergy and concurrent mite reactions are unknown. The aim of this study was to analyse the prevalence of carmine sensitization and its clinical importance among patients with suspected allergy to food additives.
The occurrence of positive SPT reactions to mites was studied in 6,464 patients: 3,164 were tested with carmine and 2,837 with shrimp. Carmine ingestion-associated symptoms were registered at the time of testing. Patients with positive SPT to carmine received a follow-up questionnaire on their symptoms 1-5 years later.
Positive SPT reactions to carmine were seen in 94 patients (3.0%) of whom 74% also had positive SPT reactions to mites and 22% to shrimp. Carmine ingestion-associated symptoms were not dependent on concurrent mite reactivity in 39/94 (42%) patients.
Carmine sensitization without sensitization to mites is seen in one fourth of the patients. Allergic reactions to carmine are not dependent on concurrent reactivity to mites.
BACKGROUND: The prevalence of asthma is strikingly different in some Westernized countries: approximately 20% in New Zealand and approximately 8% in northern Sweden. OBJECTIVE: We investigated differences in total IgE and in the prevalence of wheezing related to the observation that high exposure to dust mite allergens induces high titers of IgE antibodies. METHODS: Two age-matched, population-based cohorts-1155 children in New Zealand (224 sera) and 3431 children (797 sera) in the Norrbotten area of Sweden-were studied. Sera were assayed for total IgE and specific IgE antibodies to relevant allergens. RESULTS: The mean total IgE among wheezing children was higher in New Zealand than Sweden (218 IU/mL vs 65.2 IU/mL; P or =50 IU/mL) was greater among the wheezing children in New Zealand compared with Sweden (35.7% vs 13.0%; P or =200 IU/mL; r = 0.47; P
The major allergen in house dust comes from mites. We performed a systematic review of the randomized trials that had assessed the effects of reducing exposure to house dust mite antigens in the homes of people with mite-sensitive asthma, and had compared active interventions with placebo or no treatment. Fifty-four trials (3002 patients) were included. Thirty-six trials assessed physical methods (26 mattress covers), 10 chemical methods and eight a combination of chemical and physical methods. Despite the fact that many trials were of poor quality and would be expected to exaggerate the reported effect, we did not find an effect of the interventions. For the most frequently reported outcome, peak flow in the morning (1565 patients), the standardized mean difference was 0.00 (95% confidence interval (CI) -0.10 to 0.10). There were no statistically significant differences in number of patients improved (relative risk 1.01, 95% CI 0.80-1.27), asthma symptom scores (standardized mean difference -0.04, 95% CI -0.15 to 0.07) or in medication usage (standardized mean difference -0.06, 95% CI -0.18 to 0.07). Chemical and physical methods aimed at reducing exposure to house dust mite allergens cannot be recommended.
BACKGROUND: Low sensitization rates to common allergens have been observed in farm children, which might be due to high exposure to microbial agents. It is not known how microbial agents modify the association between specific allergen exposure and sensitization. OBJECTIVE: To examine the relations between house dust mite allergen exposure and mite sensitization in farm and nonfarm children and to assess the effects of microbial agents levels on this association. METHODS: Major mite allergens of Dermatophagoides pteronyssinus (Der p 1) and Dermatophagoides farinae (Der f 1), endotoxin, beta(1,3)-glucans and fungal extracellular polysaccharides were measured in mattress dust of 402 children participating in a cross-sectional study in five European countries. Mite allergen (Der p 1 + Der f 1) levels were divided into tertiles with cut-offs 1.4 and 10.4 microg/g. Sensitization was assessed by measurement of allergen-specific immunoglobulin E against house dust mite. RESULTS: Prevalence ratios of mite sensitization for medium and high when compared with low mite allergen levels were 3.1 [1.7-5.7] and 1.4 [0.7-2.8] respectively. Highest mite sensitization rates at intermediate exposure levels were consistently observed across country (except for Sweden) and in both farm and nonfarm children. The shape of the dose-response curve was similar for above and below median mattress microbial agent levels, but the 'sensitization peak' appeared to be lower for above median levels. CONCLUSIONS: Our data suggest a bell-shaped dose-response relationship between mite allergen exposure and sensitization to mite allergens. In populations with high microbial agent levels and low sensitization rates, the curve is shifted down.
To investigate the occupational exposure and sensitization to storage mites (SM) in sales staff working in a moisture-damaged and three healthy reference buildings.
The study population consisted of the entire personnel (n=12) in the moisture-damaged grocery store. They all suffered from persistent upper respiratory tract symptoms. Twelve (in results 11) symptom-free controls working in three healthy reference groceries were matched with age, sex and occupation. Dust samples from each building were examined for mites. The clinical study consisted of otorhinolaryngological examination and determination of IgE reactivity. Specific serum IgE antibodies were measured against three SMs and two house dust mites (HDM). Skin prick tests (SPT) were made to the same five mites and to five common aeroallergens. If sensitization to any of the SMs was detected, a nasal provocation test (NPT) was performed.
SMs were found in all buildings. In all, seven cases and four control subjects showed IgE-mediated reactivity. Sensitization to mites was detected in six cases and in three controls and in 2/12 and 3/11 this was the only IgE antibody response observed. In addition, one case and one control subject were sensitized to common aeroallergens. NPT with SMs was positive in four cases and in one control.
In grocery stores, the personnel are exposed to SMs. The risk of sensitization to mites is obvious and an IgE response can occur without any reactivity to common aeroallergens. SM allergy may in some cases explain the chronic rhinitis related to moisture-damaged buildings.
Brown Norway (BN) rats develop a robust response to antigens in the lung, characterized by a large increase in allergen-specific immune function and pulmonary eosinophilia. The objective of this study was to investigate alternative models by determining whether other rat strains could be sensitized to house dust mite (HDM) antigen and whether the allergic disease process could be worsened with repeated allergen exposure. In general, BN rats sensitized by either subcutaneous or intratracheal routes exhibited increased pulmonary allergy compared with Sprague-Dawley (SD) and Lewis (L) rats. Multiple intratracheal allergen exposures incrementally increased HDM-specific immune function in BN rats but progressively decreased eosinophil recruitment and markers of lung injury. SD rats had more moderate responses, whereas L rats were relatively unresponsive. Because BN rats developed stronger clinical hallmarks of allergic asthma under various immunization regimes compared with SD and L rats, we conclude that the BN is the most appropriate strain for studying allergic asthma-like responses in rats. Phenotypic differences in response to HDM were associated with differences in the Th1/Th2 cytokine balance and antioxidant capacity.
The respiratory health of 230 female and 1,734 male farming students (FS) and 407 male rural controls was analyzed. A significantly increased prevalence of cough (6.9%) was reported among the male FS compared to the controls (2.5%). Measured FEV1 and FVC did not differ between the male FS and the controls, as opposed to significantly higher values among the female FS compared to a random sample of urban females stratified for height. Skin prick test (SPT) to house dust and storage mites was significantly more prevalent among the controls (18.7%) compared to the male FS (12.8%) and the female FS (11.9%). The size of the house dust mite weal and the number of positive skin prick reactions were significantly associated with bronchial hyperreactivity. The difference in lung function among the female FS and the lower prevalence of skin reaction among the male FS and female FS probably reflects a healthy workers selection.