Histamine sensitivity influences reactivity to allergens

Is Body Mass Index Related to Skin Reactivity to Histamine but not to Specific Allergens? A 2-Year Follow-up Study on Korean Children

BACKGROUND

Skin prick tests are widely used to diagnose allergic sensitization. The influence of obesity on the skin prick test result has not been clearly established, even though the association between allergic disease and obesity is relatively well known.

OBJECTIVE

To determine whether a change in body mass index (BMI) contributes to skin reactivity to histamine and allergens in a skin prick test, we performed a 2-year follow-up study on Korean children.

METHODS

Skin prick tests for common aeroallergens were performed on elementary school students from Jeju Island, Korea. BMI was calculated using weight and height after measuring both, and demographic characteristics were surveyed. The same tests were repeated after 2 years.

RESULTS

The sensitization rate increased during the 2 years between tests and the children's mean BMI also increased, along with their age. The wheal sizes induced by Dermatophagoides pteronyssinus, Dermatophagoides farinae, Japanese cedar, and histamine were significantly increased during 2 years; however, only the histamine reaction associated with increased BMI had statistical significance. Furthermore, other variables-including the number of sensitized allergens-were not related to histamine skin reactivity.

CONCLUSION

Histamine skin reactivity increased in children over time and some allergens showed increased specific reactions; however, BMI gain is a specific predictor of histamine reactivity. Further studies are needed to elucidate the clinical significance of these changes.

Histamine skin reactivity increases with body mass index in Korean children

OBJECTIVE

Histamine skin prick testing is most commonly used to diagnose immunoglobulin E (IgE)-mediated allergic diseases, and histamine reactivity is used as a standardized positive control in the interpretation of a skin prick test. However, reactivity to histamine differs among individuals for reasons that are poorly understood. The present study aimed to evaluate the potential association between body mass index (BMI) and histamine skin reactivity in children.

METHODS

A total of 451 children (246 boys, 205 girls) aged 7-8 years were enrolled in this study. The skin prick test was performed with 26 aeroallergens commonly found in Korea. Other information was collected, including sex, age, BMI, parental allergy history, and parental smoking status. Multivariate analysis was used to confirm the association between histamine skin reactivity and BMI.

RESULTS

The histamine wheal size was revealed to be associated with BMI (Spearman's Rho 0.161, p<0.001). This association was confirmed by multivariate analysis, after adjusting for sex, age, parental allergy history, parental smoking status, and allergic sensitization (coefficient B 0.071, 95% confidence interval 0.030-0.112).

CONCLUSIONS

Skin responses to histamine were primarily correlated with increased BMI. Further studies are needed to understand the clinical implication of BMI when interpreting the results of skin prick test.

Histamine and allergen skin reactivity in the elderly population: results from the Korean Longitudinal Study on Health and Aging

BACKGROUND

The allergen skin prick test is the most representative diagnostic test for atopy, but its use has been limited because of the belief that skin reactivity decreases with aging.

OBJECTIVE

To investigate skin reactivity and influencing factors in the elderly population.

METHODS

This cross-sectional analysis included 854 subjects (aged ≥65 years) who participated in the Korean Longitudinal Study on Health and Aging cohort (September 2005 to August 2006) and underwent allergen skin prick tests. Skin prick tests were performed with 1 mg/mL of histamine and a panel of 12 aeroallergens that are common in Korea. The wheal diameters were measured and compared to identify the factors associated with skin reactivity.

RESULTS

Older age and female sex were associated with reduced histamine skin reactivity in elderly subjects. This age-related decrease was apparent only among women, the reasons for which were not identified. In contrast to histamine, wheal response size induced by 2 major allergens, Dermatophagoides pteronyssinus and Dermatophagoides farinae, did not show sex differences and did not decrease with age among the subjects showing allergen-induced wheal size greater than 0 mm.

CONCLUSIONS

This analysis demonstrates that age and sex can independently influence histamine skin reactivity among the elderly population. The allergen-induced wheal sizes did not decrease with age. The discrepancy between histamine and allergen skin reactivity may warrant further evaluation to redefine the cutoff value for the determination of a positive skin test result in elderly subjects.

Skin prick tests and allergy diagnosis

Skin testing remains an essential diagnostic tool in modern allergy practice. A significant variability has been reported regarding technical procedures, interpretation of results and documentation. This review has the aim of consolidating methodological recommendations through a critical analysis on past and recent data. This will allow a better understanding on skin prick test (SPT) history; technique; (contra-) indications; interpretation of results; diagnostic pitfalls; adverse reactions; and variability factors.

The influence of atopic status and potential risk factors for sensitization on histamine skin reactivity in unselected Belgian children

The histamine skin response is widely used as a standardized positive control in the performance of skin prick testing. As a part of the Aalst Allergy Study, we investigated whether histamine skin reactivity, using histamine 10 mg/mL, was influenced by age, gender, ethnic origin, environmental exposure, specific sensitization patterns, or other factors. The parents of 2021 nonselected children aged 3.4-14.8 years completed a baseline questionnaire and gave written informed consent for skin prick testing with seven common aeroallergens on their child. Sensitized children had significantly larger histamine wheal sizes than nonsensitized children (mean 4.3 vs 4.0 mm, p < 0.05). A significant difference was found in histamine wheal size between nonsensitized versus multiply sensitized children (p < 0.001), but not between mono-sensitized versus multiply sensitized children (p = 0.105). The only other factors associated with significantly larger histamine wheal sizes were a history of eczema and a history suggestive for asthma on the Brief Pediatric Asthma Screen Plus. The histamine wheal was absent in 8.9% of children. In conclusion, sensitization and some other clinical indicators of atopy were associated with a larger histamine skin wheal. Other conditions including gender and environmental exposure did not have an influence on histamine skin reactivity, which strengthens the use of histamine as a reference in skin prick testing in this age group.

Skin sensitization in school children in northern and southern Norway

It has been suggested that environmental exposures and living conditions can explain some of the worldwide variation in atopic disorders. Norway has large environmental contrasts within the country. We compared skin prick sensitization rates among school children living in the southern subarctic and in the northern arctic part of Norway. Approximately one quarter of the children were sensitized, mostly against pollen and animal dander, while mite and mould sensitization seemed to be a minor problem. Sensitization rates and profiles were similar in the north and south despite differences in living conditions and environmental exposures.

Allergen skin weal/radioallergosorbent test relationship in childhood populations that differ in histamine skin reactivity: a multi-national survey

BACKGROUND

Histamine skin reactivity (HSR, the dimension of the skin weal elicited by histamine 10 mg/mL) is a variable that differs in children from different European countries and increases over time in the same place (Italy).

OBJECTIVE

In this epidemiologic study, we investigated to what extent differences in HSR influence the relationship between positive allergen skin prick tests (ASPTs) and serum-specific IgE concentrations.

METHODS

Between October 2001 and February 2002, 591 unselected 9-10-year-old schoolchildren drawn from five small towns in central Poland (Starachowice), central Italy (Ronciglione, Guardea) and Libya (Al-Azyzia, near the Mediterranean sea and Samno, 900 km south of the coast) were analysed for histamine, common ASPT and for serum total and specific IgE.

RESULTS

HSR differed markedly in children from the three countries (Libya>Italy>Poland) whereas serum total IgE concentrations remained the same. The prevalence of children with measurable serum specific IgE (> or = 0.35 kU) or with a positive ASPT for five common allergens was high in Italy, lower in Poland and far lower in Libya. A 3-mm ASPT weal corresponded to a serum-specific IgE concentration that was two to threefold higher in children with low HSR compared with children with high HSR (P = 0.008).

CONCLUSION

These findings suggest that HSR--a variable that differs in schoolchildren populations from the three countries studied--independently influences the results of ASPT and its influence should be considered when ASPT are assessed in international studies. The HSR differences found in the populations reported here probably reflect a complex, dynamic, environmental interaction that should be monitored in the different parts of the world.

Bimodal skin reactivity to histamine in atopic children in Singapore: influence of specific sensitizations

Histamine skin prick test (SPT) is used as the 'golden standard' for positive control in in vivo immediate type hypersensitivity testing. The skin reactivity to histamine can, however, be modulated by a bevy of extraneous factors. We aimed to define whether histamine skin reactivity in atopic children in Singapore is influenced by age, ethnic origin, gender, environmental exposure or specific sensitization patterns. A retrospective analysis of children, with specific aeroallergen sensitization (as measured by at least one allergen-specific SPT with a wheal size > 3 mm compared with the negative control) from the outpatient speciality clinic of the KK Children's Hospital, during 06/2002-06/2003. A total of 315 patients were included, 235 (75%) were males, 252 (80%) were Chinese, age mean was 7.7 yr (range: 2-15). Patients were referred to the SPT with a diagnosis of one or more of: allergic rhinitis 287 (91%), asthma 112 (36%) or atopic dermatitis 60 (19%). The mean histamine response showed a bimodal distribution, independent of age, ethnic origin, gender or phenotypical expression of allergic disease. Histamine skin reactivity was higher in atopic patients with polysensitization (mean 5.0 mm vs. 2.9 mm in monosensitized patients, p < 0.001), and in patients with mould sensitization (mean 5.1 mm vs. 3.3 mm in patient not sensitized to moulds, p < 0.001). The presence of passive smoking increased the likelihood of a diminished histamine skin response. Histamine skin response data strongly suggested the presence of two heterogeneous subpopulations. Children with polysensitization and mould sensitization were more likely to show a large significant histamine response, whereas children with passive smoke exposure, showed a diminished skin reactivity to histamine.

Immediate skin reactivity to histamine and to allergens in cohorts of 9-year-old schoolchildren studied 16 years apart

BACKGROUND

Differing or increasing prevalence of positive allergen skin-prick tests observed in Europe could at least in part be explained by population changes in histamine skin reactivity. These changes would also alter the relationship between positive allergen skin-prick tests and serum IgE.

OBJECTIVE

To assess changes in histamine reactivity, allergen skin-prick tests and serum IgE in our geographical setting.

METHODS

We compared the outcome of two epidemiological surveys conducted 16 years apart in unselected 9-year-old schoolchildren (170 in 1983 and 176 in 1999) from a semi-rural region in central Italy. Outcome measures were skin-prick tests with two histamine concentrations (10 and 1 mg/mL) and 11 locally relevant allergens; serum total and specific IgE for positive allergens.

RESULTS

The two histamine concentrations induced significantly larger mean weal diameters in 1999 than in 1983 (10 mg/mL: 5.28+/-0.82 mm vs. 3.25+/-0.97 mm; P<0.001). Whereas the prevalence of subjects with at least one positive allergen-induced weal reaction (>or=3 mm) increased over the 16 years (from 15.3% in 1983 to 25.6% in 1999), the prevalence of positive skin-prick tests, expressed as the allergen/ histamine weal ratio, remained almost unchanged. A given allergen weal diameter yielded less total (P<0.05 by Student's t-test for cumulative weals <8 mm) and specific (P<0.01 by Student's t-test for weals <3 mm, P<0.05 by Kruskal-Wallis test) serum IgE in 1999 than in 1983.

CONCLUSIONS

Although the causes and mechanisms remain unclear, the increased histamine skin reactivity over time is associated with an increase in positive allergen skin-prick tests. In the presence of increased tissue and organ susceptibility to histamine, minute amounts of specific IgE could have important biological consequences.

Clinical value and measurement of specific IgE

The diagnosis of human allergic diseases involves the combined use of a careful clinical history, physical examination, and in vitro and in vivo assay methods for the detection of IgE antibodies of defined allergen specificities. In vivo (skin testing) and in vitro (measurement of specific IgE in serum) techniques cannot be considered interchangeable, the former reflecting not only the presence of IgE but also mast cell integrity, vascular and neural responsiveness. Both techniques have similarities and differences, advantages and disadvantages. Recently introduced "second generation" immunoassays have continued to improve the analytical sensitivity and reproducibility thanks to automation and improved reagent quality. Quantitative assays may allow the use of specific clinical thresholds able to differentiate symptomatic from asymptomatic patients. False-negative and false-positive results should derive from lability of some major extracts, and from possible cross-reactivities, respectively. Characterization of allergens at a molecular and submolecular level and, where necessary, the use of recombinant allergens can reduce cross-reactions and further improve the quality of immunoassays.

Skin reactivity to histamine and to allergens in unselected 9-year-old children living in Poland and Italy

Several studies have shown a higher prevalence of positive skin-prick tests to airborne allergens in Western than in Eastern European countries. We have recently reported that skin histamine reactivity significantly increased in Italy over the past 15 years. Population differences in skin histamine reactivity could, at least in part, explain the reported differences in positive allergen skin tests. To test this hypothesis we compared histamine skin reactivity and the prevalence of allergen positive skin-prick tests in a sample of Italian and Polish schoolchildren. A total of 336 unselected 9-year-old-schoolchildren (198 in Italy and 138 in Poland) underwent skin-prick tests with three different histamine concentrations (10, 1 and 0.2 mg/ml) and with a panel of common airborne allergens according to the ISAAC protocol, phase two. Mean wheals elicited by skin-prick tests with the three serial concentrations of histamine were significantly larger (p < 0.001) and shifted more toward higher values (p < 0.001) in Italian than in Polish children. The differences were greater for the intermediate histamine concentration tested (1 mg/ml) than for the highest concentration (10 mg/ml). Skin-prick tests for airborne allergens were more frequently positive in Italian children: wheals >or= 3 mm induced by any allergen [odds ratio (OR) 1.69; confidence interval (CI) 0.98-2.92] by Dermatophagoides pteronyssinus (OR 1.92; CI 0.97-3.80) and by D. farinae (OR 3.15; CI 1.16-8.63). Labeling as positive allergen wheal reactions half the size of the 10 mg/ml histamine wheal or larger reduced but did not abolish the Italian-Polish differences. The significantly higher skin histamine reactivity observed in Italian children could help to explain why allergen skin-test reactions differ in the East and West European populations. Moreover, differences in nonallergen-specific factors among populations should be considered in the interpretation of skin test results (e.g. cut-off points). To obtain meaningful results, epidemiological studies of allergies should include serial histamine dilutions.

Preliminary criteria for the definition of allergic rhinitis: a systematic evaluation of clinical parameters in a disease cohort (I)

BACKGROUND

The aim of this study is to formulate criteria for the definition of allergic rhinitis. Other studies have sought to develop scoring systems to categorize the severity of allergic rhinitis symptoms but it was never used for the formulation of diagnostic criteria. These other scoring systems were arbitrarily chosen and were not derived by any statistical analysis. To date, a study of this kind has not been performed.

OBJECTIVE

The hypothesis of this study is that it is possible to formulate criteria for the definition of allergic rhinitis. This is the first study to systematically examine and evaluate the relative importance of symptoms, signs and investigative tests in allergic rhinitis. We sought to statistically rank, from the most to the least important, the multiplicity of symptoms, signs and test results.

METHODS

Forty-seven allergic rhinitis and 23 normal subjects were evaluated with a detailed questionnaire and history, physical examination, serum total immunoglobulin E, skin prick tests and serum enzyme allergosorbent tests (EAST).

RESULTS

Statistical ranking of variables indicated rhinitis symptoms (nasal, ocular and oronasal) were the most commonly occurring, followed by a history of allergen provocation, then serum total IgE, positive skin prick tests and positive EAST's to house dust mite, perennial rye and bermuda/couch grass. Throat symptoms ranked even lower whilst EAST's to cat epithelia, plantain and cockroach were the least important. Not all symptoms, signs and tests evaluated proved to be statistically significant when compared to a control group; this included symtoms and signs which had been considered historically to be traditionally associated with allergic rhinitis, e.g. sore throat and bleeding nose.

CONCLUSION

In performing statistical analyses, we were able to rank from most to least important, the multiplicity of symptoms signs and test results. The most important symptoms and signs were identified for the first time, even though some of these were not included in our original selection criteria for defining the disease cohort i.e. sniffing, postnasal drip, oedematous nasal mucosa, impaired sense of smell, mouth breathing, itchy nose and many of the specific provocation factors.

Quantitative IgE antibody assays in allergic diseases

During the past several years, immunoassays for specific IgE antibodies have been refined to permit reporting results in mass units. Thus quantitative immunoassays for IgE antibodies may be an adjunct to skin tests. In cases of food allergy among children with atopic dermatitis, cutoff values for IgE antibody concentrations to egg, milk, peanut, and fish have been derived to provide 95% positive and 90% negative predictive values. Food-specific IgE antibody determinations can also be used to predict which food allergies are resolving spontaneously. Elevated egg-specific IgE antibody levels in infancy are associated with significantly increased risk for development of inhalant allergies later in childhood. In cases of inhalant allergy, specific IgE antibody levels correlate closely with results of inhalation challenge studies in cat-sensitive persons. Also, mite-specific IgE antibody levels correlate significantly with the mite allergen contents of reservoir dust in the homes of mite-sensitive persons. Immunoassays for quantitation of specific IgE antibodies may be used to document allergen sensitization over time and to evaluate the risk of reaction on allergen exposure. However, immunoassays and skin tests are not entirely interchangeable, and neither will replace the other in appropriate circumstances.

Atopic sensitization and respiratory symptoms among Polish and Swedish school children

Allergic sensitization and symptoms from the airways in relation to air pollution were compared in 10-12-year-old school children (n = 1113) from urban Konin in central Poland and both urban and rural parts of Sundsvall in northern Sweden. The measurements included parental questionnaires, skin-prick tests and serial peak flow measurements during 2 weeks with simultaneous monitoring of outdoor air pollutants. The skin-prick test technique was validated by IgE antibody determinations. The levels of common industrial pollutants, SO2 and smoke particles were much higher in Konin than in urban Sundsvall and the levels of NO2 were similar. Various respiratory symptoms were more often reported among school children in Konin (except for wheezing and diagnosed asthma). Multiple logistic regression analyses yielded the following increased odds ratios for children in Konin as compared with the reference group (rural Sundsvall): chest tightness and breathlessness 3.48 (95% confidence interval 2.08-5.82), exercise-induced coughing attacks 3.69 (95% confidence interval 1.68-8.10), recurrent episodes of common cold 2.79 (95% confidence interval 1.53-5.09) and prolonged cough 4.89 (95% confidence interval 2.59-9.23). In contrast, as compared with rural Sundsvall, the adjusted odds ratio for a positive skin-prick test was decreased in Konin, but increased in urban Sundsvall, 0.58 (95% confidence interval 0.37-0.91) and 1.67 (95% confidence interval 1.15-2.42) respectively. The study confirms that living in urban, as compared with rural areas, is associated with an increased prevalence of respiratory symptoms and sensitization to allergens. These differences could be explained by air pollution. Respiratory symptoms were more common in a similar urban group of Polish children who were exposed to even higher levels of air pollution. These children, however, had a much lower prevalence of sensitization to allergens, as compared with the Swedish children. This indicates that differences in lifestyle and standard of living between western Europe and a former socialist country influences the prevalence of atopy.

Effects of immunotherapy with a purified standardized allergen preparation of Dermatophagoides farinae in adults with perennial allergic rhinoconjunctivitis

Immunotherapy (IT) was performed for 12 months with a purified and standardized preparation of Dermatophagoides farinae. Twenty adults with rhinoconjunctivitis sensitive to house-dust mite were given IT, and a similar group of 11 patients served as open controls. A total of 512 injections were given. Twenty-eight episodes of allergic side-effects occurred, 13 general and 15 local, most of them during the initial incremental dose period. No severe reactions started later than 30 min after the injection. One patient suffered anaphylactic shock. In this patient, specific antibodies fell immediately, followed by an increase within 1 week. The therapy group improved significantly in relation to the open controls in patients' subjective evaluation of symptoms (P < 0.028) and skin (P < 0.0001) and conjunctival (P < 0.001) sensitivity. Specific IgE increased in controls (P < 0.0001) but not in IT-treated patients during the "mite season"; that is, there was a significant difference in change during the observation period (P < 0.0001). There was also a difference in change of specific IgG between the groups during the first 4-5 months and the whole year (P < 0.0001), but not from 4-5 months to 12 months. In contrast to changes in antibody titers (IgG, P = 0.04), changes in conjunctival (P < 0.01) and especially skin sensitivity (P < 0.005) correlated well with subjective improvement. This implies that the skin prick test and the conjunctival test can be recommended for follow-up of IT.(ABSTRACT TRUNCATED AT 250 WORDS)

Strain difference and mode of inheritance of the susceptibility to passive cutaneous anaphylaxis mediated by allogeneic IgE antibody in the mouse

The strain difference and mode of inheritance of the susceptibility to PCA (passive cutaneous anaphylaxis) were studied in mice. No marked strain differences were found in the susceptibility to PCA mediated by allogeneic IgG1 monoclonal and xenogeneic IgG antibodies, although BALB/c Crj mice were somewhat less susceptible than the other strains. On the other hand, the susceptibility to PCA mediated by allogeneic IgE monoclonal antibodies differed greatly according to the strain; SJL/J, A.SW/J and DS/Shi mice being highly susceptible and C57BL/6JShi, BALB/cCrj, DBA/2Crj, C3H/HeShi and CBA/JNCrj mice insusceptible. Based on the marked difference between DS/Shi and C3H/HeShi strains, the mode of inheritance of the susceptibility to IgE PCA was studied using their F1, F2 and F1 x parent backcross offspring. All the F1 hybrids by reciprocal crosses between these two strains and F1 x DS backcross mice were highly susceptible like DS/Shi mice. Backcross mice between F1 and C3H/HeShi showed approximately 1:1 segregation into the susceptible and insusceptible. Segregation was also observed in the F2 generation; 32% being insusceptible. These results suggest that the high susceptibility is a dominant phenotype controlled mainly by a single gene on an autosomal chromosome; this was statistically supported by tests of the segregation ratios obtained. However, in the PCA-positive recipients of F1 x C3H backcross and F2 generations, dye leakage into the skin was tended to be diffuse and less compact than in DS/Shi, F1 and F1 x DS backcross mice. This suggests the presence of some additional genes which modify the expression of the main gene.

Prospective study on immunologic changes induced by two different Dermatophagoides pteronyssinus extracts prepared from whole mite culture and mite bodies

Twenty-four children with bronchial asthma and hypersensitivity to Dermatophagoides pteronyssinus by skin titration, specific serum IgE, leukocyte histamine release, and bronchial challenge test were selected for immunotherapy with two partially purified mite extracts. On the basis of age and allergen-specific IgE responses, patients were randomly divided for treatment with either an extract prepared from whole mite culture (WMC) or from purified mite bodies (MB). The content of major allergens was quantified for both extracts. The allergen dose administered during immunotherapy was increased up to the highest tolerated dose. The mean cumulative dose of Der p I was 98.9 micrograms for the WMC-treatment group and 76.7 micrograms for the MB-treatment group. Small, but statistically significant, decreases in RAST and crossed radioimmunoelectrophoresis responses to major allergens were recorded after 2 years of treatment. A small increase in specific IgG1 and a large persistent increase in specific IgG4 was recorded in both groups. There was a significant decrease in allergen-specific bronchial sensitivity, skin reactivity, and leukocyte sensitivity in both treatment groups. Between both groups, changes in the different parameters were not significantly different. Our data indicate that immunotherapy with both partially purified house dust mite extracts, WMC, and MB leads to a decrease in allergen-specific IgE responses and induce a response in specific IgG4. Both extracts are comparable in modulating leukocyte and skin sensitivity, as well as bronchial reactivity to mite allergens.

Quantitative skin prick testing. Dose-response of histamine- and allergen-induced wheal reactions

Dose-response curves of histamine- and allergen-induced wheal areas were evaluated in seven normals (defined as negative skin prick test (SPT) to inhalant allergens and no clinical signs of allergy), seven latent allergics (positive SPT without allergic symptoms), and 20 manifest allergics (positive SPT and allergic symptoms). Three concentrations of histamine HCl (1, 10 and 100 mg/ml) and three 10-fold concentrations of nine inhalant allergens (birch, timothy, mugwort, horse, dog, cat, house dust mite, Cladosporium and Alternaria) in concentrations 1,000 10,000 and 100,000 BU/ml were used and linear regression was performed on the skin reactions. Only tests with an SD% less than 40%, a log slope greater than 0.1, and a correlation coefficient greater than 0.95 were accepted. In normals a significantly higher concentration of histamine was needed to elicit a wheal reaction of 2 mm2 (end-point) compared with allergics. Likewise, normals had a significantly higher slope i.e. steeper dose-response curve of histamine than manifest allergics. The slope of the allergen-induced wheal area was significantly higher than the histamine slope. No relation between corresponding slope of histamine and allergens was found (Rho = 0.15). The skin sensitivity equivalent to histamine calculated as the allergen concentration eliciting a wheal equal to histamine showed a median increase of 5-6 fold in allergen concentration by a 10-fold increase of histamine concentration. The highest correlation between the wheal area of a single allergen concentration and the skin sensitivity was found for allergen concentration 100,000 BU.(ABSTRACT TRUNCATED AT 250 WORDS)