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
Epidemiologic data describing the association between allergic sensitization and asthma and allergic rhinitis in adults are scarce.
To determine the prevalence and impact of specific sensitization to airborne allergens on asthma and allergic rhinitis among adults in relation to age.
A random population sample (age 21-86 years) was examined with structured interview and analysis of specific IgE to 9 common airborne allergens. Of those invited, 692 (68%) subjects participated in blood sampling. IgE level of 0.35 U/mL or more to the specific allergen was defined as a positive test result.
Allergic sensitization decreased with increasing age, both in the population sample and among subjects with asthma and allergic rhinitis. In a multivariate model, sensitization to animal was significantly positively associated with asthma (odds ratio [OR], 4.80; 95% CI, 2.68-8.60), whereas sensitization to both animal (OR, 3.90; 95% CI, 2.31-6.58) and pollen (OR, 4.25; 95% CI, 2.55-7.06) was significantly associated with allergic rhinitis. The association between allergic sensitization and rhinitis was consistently strongest among the youngest age group, whereas this pattern was not found for asthma. The prevalence of allergic sensitization among patients with asthma decreased by increasing age of asthma onset, 86% with asthma onset at age 6 y or less, 56% at age 7 to 19 years, and 26% with asthma onset at age 20 years or more.
Sensitization to animal was associated with asthma across all age groups; allergic rhinitis was associated with sensitization to both pollen and animal and consistently stronger among younger than among older adults. Early onset of asthma was associated with allergic sensitization among adults with asthma.
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: Sensitization to Dermatophagoides pteronyssinus (D. pteronyssinus) occurs in 9% of the Reykjavik population, despite the fact that no Der p 1 antigen has been found in the area. A recent study revealed that sensitized persons more often had a childhood history of work or holiday stay in rural areas than controls. As a follow up we studied the risk of exposure to mites in farmland dwellings. METHODS: In a survey of work-related lung disorders among farmers in the south and west of Iceland, 80 samples of house dust, representing 42 farms, were collected from bedroom mattresses and the floors in living rooms and examined for mites. Treatment of samples was identical with the method used earlier in the Reykjavik investigation (ECRHS II). RESULTS: In contrast to the Reykjavik results, dust from farm dwellings showed a large diversity of mites. Seventeen taxons were found, with Acarus siro and D. pteronyssinus in 13 and 8 farms respectively, but the samples did not show signs that any of the taxons actually had lived or reproduced where they were collected. CONCLUSION: The finding of D. pteronyssinus in farmland dwellings provides a possible explanation of why some Reykjavik citizens might have developed sensitization to this mite, even though cross sensitization to other species of mites could give a false positive reaction to D. pteronyssinus in at least some of those cases. Our observations did not support the idea that the mites were living in the dwellings and an explanation for their occurrence must be sought in the outdoor environment.
BACKGROUND: House dust mites (HDM) Dermatophagoides pteronyssinus are a frequent indoor allergen source. Our aim was to determine the frequencies of IgE reactivity to purified HDM allergen molecules in mite allergic patients from different parts of Europe in order to establish an allergen panel for diagnosis of HDM allergy. MATERIALS AND METHODS: Populations of D. pteronyssinus-allergic patients from Austria (n = 56), France (n = 55), Italy (n = 67) and Sweden (n = 65) and storage mite allergic patients from Sweden (n = 31) were analysed for IgE reactivity to eight purified natural (n) and recombinant (r) D. pteronyssinus allergens (nDer p 1, rDer p 2, nDer p 4, rDer p 5, rDer p 7, rDer p 8, rDer p 10 and rDer p 14) in RAST-based dot blot assays. RESULTS: Using a combination of Der p 1 and Der p 2, at least 97% of the D. pteronyssinus-allergic patients could be diagnosed in each of the HDM allergic populations. However, more than 50% of the patients also reacted with other allergens and significant variabilities regarding the frequencies of IgE reactivity to individual allergen molecules were found. Patients with a predominant storage mite allergy showed none or only very weak IgE reactivity to purified D. pteronyssinus allergens. CONCLUSIONS: Purified Der p 1 and Der p 2 are sufficient for the diagnosis of > or = 97% of D. pteronyssinus allergic patients in Europe, but other allergens may also play an important role for the diagnosis and treatment of HDM allergy.