Inhalant allergy in asthmatic children: skin prick test, radioallergosorbent test and chemiluminescent assay compared with allergen levels in their mattress dusts

Mattress dusts from the beds of 51 asthmatic children with positive skin tests to house dust mite were assayed for Der p I, Fel d I and certain viable fungi. The results of skin tests to grass, cat, dog, Alternaria, Aspergillus, Cladosporium and Penicillium, radioallergosorbent tests to cat, mite, dog and grass and the chemiluminescent assay were compared and correlations made with allergen concentrations in the dust. The sensitivity of the three tests appeared comparable (percentage agreement = 54.5-94), however, an increased level of allergen in the mattress dust was not a good indicator of the degree of sensitization of the child (p greater than 0.05).     

Allergenicity of the osmophilic fungus Aspergillus restrictus evaluated by skin prick test and radioallergosorbent test

Recently large amounts of Aspergillus restrictus, a species of osmophilic fungi, have been detected in house dust using culture media with low water activity. But little attention has been paid to this fungus as an allergen. In the present study, the authors examined the allergenic activity of A. restrictus by skin prick tests and radioallergosorbent tests (RAST) on 94 asthmatic patients (mean age 12.0, range 3-18). Aspergillus fumigatus, Alternaria alternata and house dust were used for comparison. In the skin prick tests, A. restrictus, A. fumigatus, A. alternata and house dust elicited positive reactions in 8 (8.5%), 8 (8.5%), 15 (16.0%) and 69 (73.4%) patients, respectively. RAST showed positive reactions in 27 (28.7%) subjects for A. restrictus, 22 (23.4%) for A. fumigatus, 35 (37.2%) for A. alternata, and 75 (79.8%) for house dust. These results indicated that some asthmatic individuals showed immediate-type hypersensitivity to A. restrictus, and the prevalence of hypersensitivity of A. restrictus determined by skin prick tests and RAST was comparable with that of A. fumigatus but lower than that of A. alternata or house dust. This indicates that this fungal species may be of importance as a causative agent in atopic diseases.     

The relationship between latex skin prick test responses and clinical allergic responses

BACKGROUND: Allergic responses to latex have been reported more frequently in the past 5 years. Although commercial skin prick test solutions are available and can be used in the diagnosis of latex allergy in some countries, the characteristics of patients sensitized to latex relative to their skin test responses have not been reported. OBJECTIVE: The purpose of this study is to relate the clinical characteristics of patients with latex sensitivity to the size of their latex skin prick test response. METHODS: A retrospective review of patients who were attending a hospital-based allergy and asthma clinic and who had positive skin test responses to a commercial latex skin test solution was undertaken. RESULTS: Of 47 patients who had skin test responses to latex, 36 had a mean wheal diameter at least 3 mm greater than the negative control (diluent). Sixty-eight percent were health care workers. There was a positive association between the size of skin test response and severity of latex-induced symptoms (p < 0.001). A history of banana sensitivity was also associated with larger skin test responses (p < 0.05). CONCLUSION: The size of the skin prick test response to latex solution that is commercially available in Canada reflects the severity of latex-induced clinical allergic responses. (J Allergy Clin Immunol 1996;97:1202-6.)     

Studies on the osmophilic fungus Wallemia sebi as an allergen evaluated by skin prick test and radioallergosorbent test

Recently, Wallemia sebi, a species of osmophilic fungi, has been abundantly detected in house dust using low water activity media. In this study, allergenic activity of W. sebi was assessed by skin prick test and radioallergosorbent test (RAST) in 74 asthmatic patients ranging from 6 to 32 years of age. Aspergillus fumigatus and house dust were used for comparison. In skin prick test, W. sebi extract, A. fumigatus extract and house dust extract elicited positive reactions in 4 (5.4%), 4 (5.4%) and 51 (68.9%) patients, respectively. RAST showed positive results in 14 subjects (18.9%) for W. sebi extract, in 8 (10.8%) for A. fumigatus extract and in 59 (79.7%) for house dust extract. These results indicated that some asthmatic individuals showed immediate-type hypersensitivity to W. sebi, and which means this fungal species may be of importance to atopic diseases as a causative agent.     

Relationships of total IgE level, skin prick test response, and smoking habits

Epidemiologic observations on 331 men showed that increased serum IgE concentration was associated with a wheal response to skin prick testing, but also to an erythema response in the absence of any wheal, and to heavy smoking. The association between IgE and the various skin prick test responses remained after taking into account smoking and asthma.     

Influence of skin prick test criteria on estimation of prevalence and incidence of allergic sensitization in children

In a prospective cohort study on atopy in childhood, three skin prick tests (SPT) were performed in 1135 primary schoolchildren over a 2–year period. We studied the development of average sizes of allergen wheals in reactive children and of average sizes of histamine wheals in all children, and we investigated the influence of choice of SPT criterion on the prevalence and incidence of sensitization. A year-to-year increase of average allergen wheal sizes as well as of average histamine wheal sizes was observed. These increases seemed to be related to the natural growth of the children. Furthermore, an observer bias effect of the person who did the pricking on average wheal sizes was found. There were considerable differences in estimations of prevalences and incidences depending on the definition of SPT criterion. Estimations using a criterion based solely on the allergen wheal size were affected by variation of allergen wheal sizes caused by growth and observer effects. The ratio criterion was not influenced by observer effects, nor did it seem to be affected by aging effects. In conclusion, our data suggest that the ratio criterion, which relates the size of the allergen wheal to the size of the histamine wheal, is the most appropriate SPT criterion because it is not affected by growth of allergen wheals in childhood and it appears to compensate for possible observer bias.     

A comparison of different allergometric tests,skin prick test,Pharmacia UniCAP and ADVIA Centaur,for diagnosis of allergic diseases in children

BACKGROUND: The diagnosis of allergic disease is performed by skin prick tests (SPT) or through the demonstration of specific IgE in a blood sample via an in vitro test. The measurement of IgE concentration against allergens provides critical information in clinical allergy. Standardized and reproducible methods contribute to the quality of diagnosis and treatment of allergic disease. METHODS: In this study we evaluated the performance of a new specific IgE method, developed by ALK-Abellò for Bayer Diagnostics to run on their ADVIA Centaur immunoassay system. One hundred and fifty-one children with allergic diseases (both food and inhalant allergies) were tested for specific IgE (sIgE) via SPT and in vitro tests (UniCAP system, Pharmacia, and ADVIA Centaur immunoassay system, Bayer Diagnostics) and the test results were correlated with the clinical data. RESULTS: Statistical analysis revealed no significant difference between the two in vitro tests compared with clinical history. The sensitivities and specificities are similar, but the UniCAP system method has higher sensitivity. In the children with cow's milk allergy, the UniCAP system has sensitivity of 91% and specificity of 70%; the ADVIA Centaur immunoassay has sensitivity of 82% and specificity of 74%. In hen's egg allergy, UniCAP system has 94% sensitivity and 64% specificity, and the ADVIA Centaur system has 88% sensitivity and 52% specificity. In inhalant allergies, the two methods show statistically similar performances for both grass pollen allergies (UniCAP sensitivity 100%, specificity 73%; ADVIA Centaur sensitivity 95%, specificity 79%) and in the dust mites allergies (UniCAP sensitivity 91%, specificity 62%; ADVIA Centaur sensitivity 86%, specificity 64%). In cat allergies, the systems showed equivalent results (UniCAP sensitivity 100%, specificity 71%; ADVIA Centaur sensitivity 100%, specificity 70%). Using the UniCAP system, the geometric mean of sIgE values in children with clinical allergy is significantly higher than in sensitized ones. The ADVIA Centaur system shows a similar trend with the exclusion of cow's milk and Dermatophagoides farinae allergens. With this last method the mean value of sIgE is higher in sensitized than in symptomatic children. CONCLUSION: The new ADVIA Centaur method compares favorably with the results obtained on the UniCAP system. If other studies continue to confirm this data, then the advantages are numerous: the use of only a small quantity of serum (25 micro l per allergen), rapid turnaround time, minimal hands-on time, and no interference from IgG.     

Dose response relationship of allergen, histamine, and histamine releasers in skin prick test and precision of the skin prick test method

The aim of the present investigation was to study the dose response relationship of allergen, histamine and histamine releasers in skin prick test (SPT) and the precision of the SPT method. In one experiment timothy allergen, histamine HCl, rabbit anti-human-IgE and compound 48/80 were studied in seven patients. In a second experiment timothy allergen and histamine and dog allergen and histamine were investigated in two groups of 10 patients. Histamine HCl 1 and 10 mg/ml induced weals about 15 and 25 mm2 (4.5 and 5.5 mm in diameter), respectively. The precision as expressed by the coefficient of variation was about 25% for histamine and 40% for allergen for weal areas greater than 10 mm2. Calculations of the regression lines to test the dose response relationships were based on the method of least squares. The best fit was to a log/log model. The slopes of allergen, histamine and histamine releasers were essentially parallel within patients. The median slope of allergen was estimated to about 0.4 based on weal areas and 0.2 based on mean weal diameters. Furthermore, no significant differences were found between the lower and upper parts of the dose response curves of allergen and histamine, although there was a tendency towards steeper slopes at lower concentrations. These results show that histamine concentrations greater than or equal to 1 mg/ml should be used as positive control in SPT and that histamine releasers do not offer advantages over histamine as reference substances in SPT. A common slope for the dose response relationship of allergen and histamine can be used for the estimation of skin sensitivity.     

Reproducibility of the skin prick test

Reproducibility of the skin prick method of testing for allergy was studied in 20 subjects examined by four nurses. Hypodermic needles were used for pricking and the test panel included a histamine control, a diluent control, and nine allergens. The reproducibility of the method was best when the size of the weal reaction caused by an allergen was expressed as the geometric area of the weal. When the weal reaction was expressed as the ratio of the weal reaction caused by an allergen to that caused by histamine, the reproducibility of the method was decreased considerably. When the ratios were further classified into three class ratings, reproducibility was very low. The reduction in reproducibility was due to the low reproducibility of histamine reactions. According to these results, at least in epidemiological studies the weal reactions should be expressed as geometric areas. In clinical practice it might also be preferable to express prick test results as the diameters of the weals without adjusting them by histamine reactions.     

High incidence of adverse reactions to egg challenge on first known exposure in young atopic dermatitis children: predictive value of skin prick test and radioallergosorbent test to egg proteins

BACKGROUND: Egg skin prick test (SPT) and/or radioallergosorbent test (RAST) positivity has been described in infants and children with a food allergy, or in infants at high risk of atopy who have never eaten eggs. Clinical reactions are also observed when some of these children or infants eat eggs for the first time. OBJECTIVE AND METHOD: A prospective study was made of 107 atopic dermatitis (AD) children (66 boys, 41 girls) aged 1-19 months (median 5 months) who had never ingested egg, to compare the outcome of a first oral egg challenge and the results of albumen and yolk SPTs and RASTs. RESULTS: The egg challenge (conducted at age 12-24 months: mean 16 months, median 15 months) was positive in 72/107 children (67.3%). The reactions were immediate or early (first 6 h) in 56/72 (77.8%). The most severe (all within the first 6 h) were one case of anaphylactic shock (1.4%), three cases of laryngeal oedema (4.1%) and one serious attack of asthma (1.4%). The skin weal diameter at and above which reactions always occurred was 5 mm for both albumen and yolk. They were, however, also observed in the complete absence of a weal. The outcome of the challenge was always positive when the specific IgEs (sIgE) for albumen and yolk were > 99 KU/L and > or = 17.5 KU/L, respectively. Here, too, reactions were noted even when sIgE levels were < 0.35 KU/L. CONCLUSION: AD children who have never eaten eggs may be sensitized and display reactions at the first ingestion. The percentage of reactions in this series was by no means negligible. These findings were observed in children with mild as well as moderate-severe AD when first examined. SPT for albumen and yolk diameter > or = 5 mm, and sIgE for albumen > 99 KU/L and for yolk > or = 17.5 KU/L were 100% specific in predicting the outcome of the challenge. It may thus be concluded that children with AD whose SPT and/or RAST for albumen and/or yolk are equal to or higher than these cut-off values should not be subjected to the oral challenge when consideration is given to the introduction of egg in their diet. Even when these cut-offs are not reached, however, clinical reactions to the challenge cannot be ruled out a priori, and it should be preferably performed in a protected environment, such as a hospital.     

Comparison between two different assays for measurements of allergen-specific IgE and skin prick test in the diagnosis of insect venom allergy

Forty-one patients stung by wasp and 29 by bee were evaluated by comparing the correlation between skin prick test (SPT), Phadebas radioallergosorbent test (P-RAST) and Magic Lite SQ Specific IgE assay (LIA). All patients had had a systemic reaction to insect sting. In the patients stung by bee we found agreement between SPT and P-RAST, and SPT and LIA. Similarly, there were no significant differences in sensitivity between P-RAST and LIA (p > 0.05). In patients stung by wasp, SPT was found to be more sensitive than P-RAST. There were no differences between SPT and LIA or between P-RAST and LIA.     

Correlation of MAST chemiluminescent assay (CLA) with RAST and skin prick tests for diagnosis of inhalant allergic disease

The purpose of this study was to compare the new multiple allergosorbent chemiluminescent assay (MAST CLA) system with the RAST and skin prick tests as an adjunct to the diagnosis of inhalant allergies. In this report, MAST CLA and RAST have given similar results, but no technique is as sensitive as skin tests for allergen-specific diagnosis of inhalant allergic disease.     

Association between alcohol consumption and skin prick test reactivity to aeroallergens.

BACKGROUND: A few studies have indicated a positive association between consumption of alcohol and allergic sensitization in age and socioeconomically heterogeneous populations. OBJECTIVE: To investigate the association between consumption of alcohol and allergic sensitization in a young homogenous population of high social class (a group with a suspected high prevalence of sensitization). METHODS: A total of 1,668 students aged 18 to 35 years recruited from universities in Copenhagen, Denmark, underwent skin prick testing (SPT) in October or November 2002 and completed a questionnaire about respiratory disease and lifestyle habits, including alcohol consumption. SPT positivity was defined as a positive reaction (> or =3 mm) against at least 1 of 10 common inhalant allergens. RESULTS: Before and after adjustment for sex, age, smoking, atopic predisposition, and pet keeping, no significant association was found between alcohol consumption (including type of beverage) and SPT positivity. Increasing alcohol consumption was significantly negatively associated with asthma symptoms and hay fever symptoms. CONCLUSIONS: Alcohol consumption does not favor SPT positivity, but cumulated effects were not addressed in the present study. Individuals with asthma or hay fever symptoms seem to reduce alcohol intake (a healthy drinkers' effect).     

Comparison of in vitro assay for specific IgE and skin prick test with intradermal test in patients with allergic rhinitis

Among many diagnostic tests for allergic rhinitis, the intradermal (ID) test is practical and reliable. However, there are several factors affecting compliance, practicability and interpretation, and also problems on hypersensitivity of the ID. For these reasons, we evaluated other tests which have been thought to have high reliability as diagnostic and/or screening assays, namely, skin prick test and specific IgE detection in seventy-four perennial rhinitis patients (51 males and 23 females whose ages were between 15-60 years). In this study, Dermatophagoides pteronyssinus and D. farinae extracts, known to be the most common aeroallergens in Thailand, were used as the allergens/antigens. Compared to the standard ID test, sensitivities to D. pteronyssinus and D. farinae of the studied patients tested by skin prick test were 90.4% and 86.4%, and specificities were 99.5% and 93.1%, respectively. Sensitivities to D. pteronyssinus and D. farinae using specific IgE assay were 96.3% and 88.9%, and specificities were 96.2% and 88.9%, respectively. It was concluded that the skin prick test can be used as a screening method for patients with allergic rhinitis, while the specific IgE detection can be used as an alternative for diagnosis of patients who are susceptible to the ID test or for those who are severely susceptible to allergic rhinitis such that medication can not be withdrawn for the ID test.     

Longitudinal variability of skin prick test results

The skin prick test (SPT) is a commonly used procedure for assessing a specific sensitization. The longitudinal variability of test results is of interest for clinical as well as epidemiological investigations. The sensitization to four common aeroallergens (grass pollen, birch pollen, Dermatophagoides pteronyssinus, cat dander) is investigated within the framework of three consecutive SPTs at 11-month intervals for a population of 587 schoolchildren. The prevalence of sensitization based on a weal diameter of at least 2 mm was between 12.9% (cat dander) and 23.9% (grass pollen) in the initial testing. The positive predictive values of the initial SPT were between 75.3% (birch pollen) and 88.2% (cat dander) for the two subsequent SPTs. In the case of initially negative tests with positive second and third SPTs the incidence ranged between 3.2% (cat dander) and 4.3% (birch pollen) per year. A clear increase in the intensity of reaction in subsequent tests was observed in a number of probands testing positively in the initial SPT. In conclusion, our data indicate a high long-term stability of a specific sensitization to aeroallergens in SPT.     

Total serum IgE, allergy skin testing, and the radioallergosorbent test for the diagnosis of allergy in asthmatic children

Correlations of total serum IgE, skin test reactivity, and specific IgE antibodies to selected antigens were evaluated in asthmatic children. There was a significant difference in mean IgE level of each positive RAST score group compared with that of the RAST-negative score for dog epithelium, Candida, ragweed, and Bermuda grass allergen. The correlation coefficient between the total IgE and the RAST to D. farinae was 0.39 (P less than .05). There was no significant correlation between the total IgE and the RAST to D. pteronyssinus, Candida, dog epithelium, ragweed, Eucalyptus pollen, and Bermuda grass (P greater than .05). This indicates a low total serum IgE concentration does not exclude the possibility of significant elevation of specific IgE to a common allergen. Concordance for results of intradermal skin testing and RAST was high for most allergens. Lower efficiency for dog allergen and Candida suggests greater sensitivity of allergy skin testing for these allergens.     

Relationships between allergic inflammation and nasal airflow in children with seasonal allergic rhinitis.

BACKGROUND: Allergic rhinitis is characterized by a T(H)2-dependent inflammation. Nasal obstruction is a typical symptom of allergic rhinitis. OBJECTIVE: To evaluate the possible relationships among nasal symptoms, allergic inflammation, including inflammatory cells and cytokine pattern, and nasal airflow in children with seasonal allergic rhinitis. METHODS: Children with seasonal allergic rhinitis and moderate-severe nasal obstruction were evaluated during the pollen season. Total symptom score, rhinomanometry, nasal lavage, and nasal scraping were evaluated in all patients. Inflammatory cells were counted by conventional staining; interleukin 5 (IL-5) and IL-8 levels were measured by immunoassay on fluids recovered from nasal lavage. RESULTS: Twenty children (11 boys and 9 girls; mean +/- SD age, 12.9 +/- 1.7 years) participated in this study. Eosinophil levels were significantly associated with total symptom score (r = 90.6%, P < .001), IL-5 (r = 94.9%, P < .001), and nasal flow (r = -93.6%, P < .001). No association was elicited with IL-8 (r = 9.4%, P = .69). In a multivariate analysis that included eosinophils, neutrophils, and IL-5, eosinophil levels were shown to be the only independent predictor of nasal flow. CONCLUSIONS: This study demonstrates the close connection between T(H)2 cytokines and eosinophil infiltration. In addition, there is clear evidence concerning the relationship among nasal symptoms, eosinophil infiltration, and nasal airflow. These findings constitute evidence of the relationship between nasal airflow impairment and eosinophilic inflammation in children with seasonal allergic rhinitis.