Allergic People Research Articles

The Irritation of House Dust: DEHP Heightens Inflammatory Response in Allergy Sufferers

Past research has suggested that di(2-ethylhexyl) phthalate (DEHP), a commonly used plasticizer, contributes to asthma symptoms in children [EHP 116:98–103 (2008)] and to dermatitis caused by dust mite allergens in mice [EHP 114:1266–1268 (2006)]. Both the prevalence of allergic diseases and environmental exposure to phthalates have increased dramatically in the past several decades, but few studies have examined how people’s mucosal airways respond to inhaled DEHP. A new study reveals that exposure to DEHP in house dust altered the response of nasal mucosa in allergic people but not in nonallergic people [EHP 116:1487–1493; Deutschle et al.]. DEHP is found in polyvinyl chloride pipes, flooring, food containers, and other household products. Oral intake is the main route of exposure, but inhalation offers an alternative route. DEHP vaporizes from consumer products directly into the home and attaches to inhalable airborne dust particles. The subjects included 16 controls and 16 people who were allergic to house dust mites. The researchers exposed the subjects to one of two house dust samples—vacuumed samples containing 0.41 mg/g (DEHPlow) or augmented samples containing 2.09 mg/g (DEHPhigh)—for 3 hours. Nasal fluid was collected after exposure to measure biomarkers of allergic inflammation, including interleukin (IL)-2, -4, -5, -6, and -8, granulocyte colony–stimulating factor (G-CSF), and eosinophilic cationic protein (ECP). The expression of 1,232 genes was analyzed by microarrays in biopsies obtained from one nostril. Following either DEHP dose, the nonallergic group experienced no changes in nasal mucosa, and biomarker levels did not change significantly. However, DEHP exposure was associated with biomarker changes in the allergic group: half the allergic subjects challenged with DEHPlow showed significantly elevated levels of G-CSF, ECP, IL-5, and IL-6, whereas other allergic subjects exposed to DEHPhigh showed significantly diminished levels of G-CSF and IL-6, suggesting a reduced immune response. DEHP is a known modulator of gene expression, as illustrated by the current study results. Among healthy subjects, between the two exposure groups, 6 genes were upregulated and 4 were down-regulated. Among allergic subjects, between the two exposure groups, 8 genes were upregulated and 8 were downregulated. One of the genes elevated by DEHP was anti-Mullerian hormone, which is associated with proper gonad development in males. DEHP dampened the expression of lactate dehydrogenase A and fibroblast growth factor 9, regulators of testis formation. Although the gene expression data shed little light on allergic reactions, they support earlier evidence for phthalates’ action as endocrine disruptors that can impair reproductive tract development.

Allergy After Inhalation and Ingestion of Cereals Involve Different Allergens in Allergic and Celiac Disease

Cereals are among the major foods in type I food hypersensitivity reactions. Hypoallergenic cereals and recombinant immunotherapy have been recently patented. In celiac disease, limited information is available regarding cereal allergens responsible for allergic reactions. The allergenic reactivity of ingested and inhaled cereal allergens in allergic and celiac people are discussed in the manuscript. Allergic sensitisation IgE mediated to cereals may be observed in celiac children. Inhalation and ingestion routes causing cereal allergy seem to involve similar allergens, but, in celiac disease specific response to CM3 may be important.

Honeybees and caterpillars: epidemiology of accidents involving these animals in the Criciúma region, southern Santa Catarina State, Brazil

The present study aimed to acquire knowledge regarding some aspects of the epidemiology and injuries provoked by honeybees and caterpillars in southern Santa Catarina State, Brazil. Epidemiological information concerning accidents with both animals was prospectively collected from the System of Injury Notification Information (SINAN) files of the Municipal Health Secretary of the Criciuma region, Brazil. Between 1994 and 2006, 203 cases of accidents were registered, 149 provoked by honeybees (73.39%) and 54 by caterpillars (26.61%). The majority of the victims (200 cases) presented full recovery, two cases presented sequelae after recovery, and only one death was recorded in a case involving honeybee injury. The high frequency of victim recovery suggests that the public health system is efficient and the low frequency of sequelae after recovery also suggests that this system is fast and well developed. However, the low number of allergic people in this population should be considered as well as the severity level of the recorded accidents.

Synchronized inter‐annual fluctuation of flowering intensity affects the exposure to allergenic tree pollen in North Europe

Many anemophilous, early‐flowering tree genera include allergy plants of world‐wide significance. We studied the synchronisation of high and low pollen years in the genera Betula, Alnus, Corylus, Salix and Populus and the cumulative effects that an increasing number of taxa has on the number of days of exposure to different levels of allergenic pollen in North Europe. The proximal causes of the inter‐annual variations of airborne pollen loads were analysed with a multiple regression analysis. The annual fluctuations of airborne pollen sums were compared between genera and found to be positively correlated among all combinations of genera at the three study sites. Most correlations were statistically significant (p<0.05). The comparison between Betula and Alnus is discussed first. Betula pollen was clearly the most abundant airborne pollen type. The presence of Alnus pollen, however, significantly increased the predisposal to allergenic pollen. At all sites, the number of days per year when the Betula and Alnus pollen counts together exceeded 10 and 100 grains m−3 of air, was found to be greater than the number of days when the Betula pollen counts alone exceeded 10 and 100 m−3 of air. The difference was statistically significant. In Kuopio, the difference was found to be statistically significant even for grains per 1 000 m−3 of air of Betula and Alnus together compared with the same count of Betula pollen alone. Betula, Alnus and Corylus belong to the order Fagales and have cross‐reacting main allergens. The flowering of Alder and Corylus culminate at the same time, two to four weeks earlier than that of Betula. Due to synchronization of high and low years and the mostly non‐overlapping flowering seasons, the time of exposure to pollen may be very long during the high years. Furthermore, Alnus and Corylus pollen may prime allergic people before the onset of the Betula season.

Detection of Horse Allergen around a Stable

Background: Integrating horse stables with built-up areas may lead to conflicts. Dispersion of horse allergen may become a health risk for allergic people. The aim was to measure the dispersion of horse allergen around a stable, considering wind speed and direction and vegetation. The disturbance of staff at a workplace nearby a stable was investigated. Methods: Air sampling was performed around a stable (32 horses) at distances of 50–500 m in all directions. Sampling was done with a pump and an IOM sampler. Samples were collected at 50 points during all seasons. Horse allergen levels were determined using ELISA. Disturbance by horses was studied with a questionnaire handed to the employees in an office near the stable. Results: The median horse allergen level at the stable entrance was 316 U/m³, in the horse fields 40 U/m³ and in the whole source area 16 U/m³, which declined to <2 U/m³ at about 50 m from the source area. Downwind of the prevailing winds low levels of horse allergen (2–4 U/m³) could sometimes be detected at up to 500 m. The staff, including those allergic to horses, managed to tolerate horses close to the workplace. Conclusions: At low winds horse allergen spread in ambient air about 50 m from the stable and horse fields. At higher winds low allergen levels were sometimes found in open areas up to 500 m from the source area. These levels were similar to those found in the office after moving away from the stable area. The employees did not report more symptoms of allergy or asthma while working close to the stable compared to after the move.

Date Palm Pollen Allergoid: Characterization of Its Chemical-Physical and Immunological Properties

Background: Date palm (DP) pollen can cause allergic symptoms in people living in different countries. Specific immunotherapy with allergenic extracts by subcutaneous route is effective to cure allergic people. However, the risk of side effects has led to explore safer therapeutic modalities. The aim of our work was to evaluate IgE cross-reactivity between DP and autochthonous palm (European fan palm, EFP) pollen extracts, to chemically modify DP extract with potassium cyanate in order to obtain an allergoid, and to characterize it. Methods: By radioallergosorbent test inhibition, immunoblotting (IB) and skin prick test, in vitro and in vivo allergenic activities of native and modified DP extracts were compared. By SDS-PAGE and IB, we compared the protein profile and IgE-binding capacity of both native and modified DP, as well as of EFP extracts. By IB inhibition, IgE cross-reactivity of native DP and EFP extracts was evaluated. By ELISA, the capacity of modified DP-induced IgG to react with native DP extract was determined. Results: Radioallergosorbent test inhibition, IB and skin prick test results demonstrated that modified DP was significantly less allergenic than native DP extract. The SDS-PAGE profile showed that potassium cyanate treatment of DP extract did not alter the molecular weight of its components. In addition, no difference was observed between native DP and EFP extracts. Subsequent IB inhibition data evidenced the existence of a strong IgE cross-reactivity between native DP and EFP extracts. ELISA results indicated that the administration of modified DP in mice was able to induce specific IgG also recognizing native DP extract. Conclusions: Modified DP extract (allergoid) seems to be a good candidate for immunotherapy of patients affected by specific allergy.

Bad news for cats: Cat allergen hits all allergic people

Bad news for cats: Cat allergen hits all allergic people

T and B cell responses to HDM allergens and antigens

House dust mites provide well-characterized proteins to study human responses to inhaled antigens. Even in the absence of allergy they induce a high frequency of T cell precursors. The healthy response manifests by T cell proliferation and Th1 cytokines with little antibody. Responses of allergic people include Th1 and Th2 cytokines and IgE, IgG1, and IgG4 antibodies. Regulatory cells limit effector responses in healthy people. About half the IgE and IgG antibodies bind the group 1 and 2 allergens and 30% bind the group 4, 5, and 7 allergens. Although HLA independent, the recognition of the group 1 allergen shows an immunodominant region and a T cell receptor bias. The major allergens are not produced in higher amounts than many of the poorly non-allergenic proteins. The non-allergenic mite ferritin antigen shows high T cell proliferative responses with mixed cytokine production.

Antigen-Driven HIV Expansion in Allergen-Specific T Cells

In industrialized countries there is a high prevalence of allergy toward nickel ions. The exposure of affected individuals to nickel leads to a delayed-type hypersensitivity reaction, which is induced by antigen-specific CD4 and CD8 T cells. Beside this antigenic potential, immunomodulatory properties of nickel ions were described. To dissect the role of both mechanisms for HIV replication, we studied HIV expansion in PBMC of nickel-allergic and nonallergic donors. Nickel ions promote HIV replication in PBMC as efficiently as protein antigens. The nickel-mediated virus expansion strictly required the presence of nickel-specific T cells. Data obtained with nickel-specific CD4 T cell clones showed that antigen-mediated proliferation is an absolute prerequisite for HIV expansion. However, the previously suggested immunomodulatory properties of nickel ions do not seem to contribute to HIV expansion. As a widely distributed antigen with increasing numbers of allergic people, nickel may be an important and underestimated factor of HIV expansion in vivo.

Consumers with Allergic Reaction to Food

This article examines perceptions of and response to food risk by consumers who are allergic to or intolerant of certain food types. Food risk in general and risk related to genetically modified (GM) food are discussed, as well as issues of responsibility and judgment regarding food labeling. Eight hundred individuals were recruited for a postal questionnaire study. The response rate was 63% for allergic people and 59% for nonallergic. The results suggest that the experience of personal harm from food in the form of allergic or intolerant reactions can influence how people evaluate food risk. For example, the ranking of food risks demonstrated a difference of perception with respect to naturally occurring food allergens. The allergic group was more disposed to buy genetically modified products that had been engineered not to contain allergens. Allergic consumers also were inclined to take more individual responsibility for risk avoidance than consumers without allergies.

Changes in the pollen seasons of the early flowering trees Alnus spp. and Corylus spp. in Worcester, United Kingdom, 1996–2005

Previous work on Betula spp. (birch) in the UK and at five sites in Europe has shown that pollen seasons for this taxon have tended to become earlier by about 5-10 days per decade in most regions investigated over the last 30 years. This pattern has been linked to the trend to warmer winters and springs in recent years. However, little work has been done to investigate the changes in the pollen seasons for the early flowering trees. Several of these, such as Alnus spp. and Corylus spp., have allergens, which cross-react with those of Betula spp., and so have a priming effect on allergic people. This paper investigates pollen seasons for Alnus spp. and Corylus spp. for the years 1996-2005 at Worcester, in the West Midlands, United Kingdom. Pollen data for daily average counts were collected using a Burkard volumetric trap sited on the exposed roof of a three-story building. The climate is western maritime. Meteorological data for daily temperatures (maximum and minimum) and rainfall were obtained from the local monitoring sites. The local area up to approximately 10 km surrounding the site is mostly level terrain with some undulating hills and valleys. The local vegetation is mixed farmland and deciduous woodland. The pollen seasons for the two taxa investigated are typically late December or early January to late March. Various ways of defining the start and end of the pollen seasons were considered for these taxa, but the most useful was the 1% method whereby the season is deemed to have started when 1% of the total catch is achieved and to have ended when 99% is reached. The cumulative catches (in grains/m(3)) for Alnus spp. varied from 698 (2001) to 3,467 (2004). For Corylus spp., they varied from 65 (2001) to 4,933 (2004). The start dates for Alnus spp. showed 39 days difference in the 10 years (earliest 2000 day 21, latest 1996 day 60). The end dates differed by 26 days and the length of season differed by 15 days. The last 4 years in the set had notably higher cumulative counts than the first 2, but there was no trend towards earlier starts. For Corylus spp. start days also differed by 39 days (earliest 1999 day 5, latest 1996 day 44). The end date differed by 35 days and length of season by 26 days. Cumulative counts and lengths of season showed a distinct pattern of alternative high (long) and low (short) years. There is some evidence of a synchronous pattern for Alnus spp.. These patterns show some significant correlations with temperature and rainfall through the autumn, winter and early spring, and some relationships with growth degree 4s and chill units, but the series is too short to discern trends. The analysis has provided insight to the variation in the seasons for these early flowering trees and will form a basis for future work on building predictive models for these taxa.

Ocorrência e coleta de colônias e de enxames de abelhas africanizadas na zona urbana de Maringá, Estado do Paraná, Brasil

During the last years, a great number of swarms of Africanized honey bees migrated to the urban zone of Maringá, Paraná State, Brazil, causing a great concern, mainly in those who live at home with children, elderly and allergic people. This study aimed to record and remove the colonies and swarms reported to the Animal Science Department at Universidade Estadual de Maringá from 1997 to 1999, in order to avoid possible problems caused by honey bees (Apis mellifera) to the community and use them for research and teaching purposes. 283 reports were recorded, being 226 (79.9%) colonies and 57 (20.1%) swarms. 191 (67.5%) of the total reports were collected, being 169 (88.5%) colonies and 22 (11.5%) swarms. The honeybees were generally located in roofs (123; 43.5%), boxes (64; 22.6%), floors (59; 20.8%) and trees (37; 13.1%)

Aerobiological studies and low allerginicity of Date-Palm pollen in the UAE

Date-Palm trees (Phoenix dactylifera L.) are the most abundant crop in the United Arab Emirates (UAE). The aim of this work was to conduct aerobiological studies on Date-Palm pollens and correlate that to allergenicity. An aerobiological survey was performed at three Date-Palm farms. Radioallergosorbent test (RAST) and total IgE were performed on 477 airborne allergic patients. Small mass bioactive constituents were fractionated and isolated by HPLC. Aerobiological studies demonstrate the short distance traveled by the Date-Palm pollens. Pollen counts were about 800 counts/m3 within the Date-Palm farms and decreased by about 80% just 100 meters away from the farm area and almost diminished beyond 200 meters. Scanning electron micrograph of the pollen grain showed a uniform smooth texture with an oval shape. Out of 477 airborne allergic patients having high total IgE counts, only 2.3% gave positive RAST for Date-Palm pollen. HPLC chromatogram separated the non-protein content of Date-Palm pollen into four distinct peak fractions. The present study revealed that Date-Palm pollens have a low allergic effect on airborne allergic people. The short distance traveled by the pollen, the smooth texture, the short pollination period and low molecular weight biomolecule content may be the main factors behind the low allergenicity.

Comparação entre a composição química determinada e a declarada na embalagem de diferentes marcas de pão de queijo

O pão de queijo, fabricado com fécula fermentada de mandioca (polvilho azedo), queijo e ovos, é um alimento nutritivo e fonte alternativa de carboidratos para pessoas alérgicas ao glúten do trigo. É um produto tradicionalmente caseiro, de fácil e rápido preparo; porém, hoje já é bastante industrializado, congelado e exportado. Há, porém, falta de controle de qualidade, tornando-se necessário otimizar a produção e caracterizar a matéria-prima, ingredientes e produto. O presente trabalho foi desenvolvido no Departamento de Ciência dos Alimentos da Universidade Federal de Lavras com o objetivo de comparar a composição centesimal do pão de queijo com a composição declarada na embalagem. A composição centesimal, pH e acidez titulável foram determinados na massa e no pão de queijo assado. Foram notadas diferenças na composição química entre as massas e entre os pães de queijo assados. Na comparação com os dados das embalagens, observou-se que os teores de proteínas foram inferiores aos valores calculados. Em duas marcas, os teores de lipídios também apresentaram valores menores e quanto à energia, uma marca subestimou o valor calórico do produto.

Masting by Betula-species; applying the resource budget model to north European data sets.

Masting, the intermittent production of large crops of flowers by a plant population, is a common feature among trees in boreal and temperate forests. The pollen of many broadleaved trees causes allergic diseases, which are major causes of increasing health-care costs in industrialised countries. As the prevalence and severity of allergic diseases are connected with the concentrations of airborne pollen, an universal model predicting the intensity of the coming flowering would be a valuable tool for pollen information services, and ultimately for allergic people and allergologists. We investigated whether a resource budget model created in Japan explains the fluctuations in the annual pollen sums of Betula-species in north European data sets (10-12 years at 4 sites, 20 years at 10 sites). Using the shorter data sets, the model explained 76-92% of the annual fluctuations at five study sites. Using the 20-year data set, the percentage for southern Finland was much lower, only 48%, compared with the 85% of the 12-year data set. The annual pollen sums have been higher during the 1990s than in the 1980s, which may explain the ineffectiveness of the model, while applied to the 20-year data set. Our results support the resource budget model: the masting of birch species is regulated by weather factors together with the system of resource allocation among years. The model can serve pollen information service. However, only the 10 most recent years should be used to avoid interference from trends in changing vegetation and/or climate.

Expression and epitope analysis of the major allergenic protein Fag e 1 from buckwheat

Seeds of common buckwheat ( Fagopyrum esculentum) contain valuable nutritive substances but also allergenic proteins that cause hypersensitive reactions. Thus, the development of hypoallergenic buckwheat would make this important pseudo-cereal available to allergic people. A major allergenic protein of buckwheat is Fag e 1. We isolated the respective cDNA, coding for a 22 kDa protein, from a recently developed autogamous strain of common buckwheat and confirmed its immunoglobulin E (IgE)-binding activity using recombinant Fag e 1 and sera of allergic patients. The derived amino acid sequence from Fag e 1 cDNA was used to synthesize an overlapping peptide library on nitrocellulose membranes for the determination of the Fag e 1 epitopes. We identified eight epitopes and the critical amino acids for IgE-binding within the epitopes. This epitope analysis of a major allergenic protein of buckwheat should help therapeutic efforts and aid in the development of hypoallergenic buckwheat.

Hev b 9, the latex enolase, a necessary reagent of a mold allergy diagnostic panel?

Rationale Enolases are important mold allergens. We investigated mold allergic patients' sensitization to the allergenic latex enolase Hev b 9 and its cross-reactivity with the allergenic mold enolase Alt a 5. Methods Sera of 167 subjects with allergy to molds, 57 subjects with allergy to latex, and 19 patients with allergy to molds and latex—characterized by positive clinical history and positive CAP—were evaluated in ELISA experiments on recombinant (r)Hev b 9 or rAlt a 5, the enolase from Alternaria alternata. Results In the group of mold allergic subjects 45/167 displayed IgE to rAlt a 5, 35/167 to rHev b 9, and 16/167 to both allergens. Sera of 4/57 latex allergic patients contained IgE specific for rAlt a 5, 3/57 for rHev b 9, and 2/57 for both allergens. Sera of 2/19 of the mold and latex allergic patients displayed IgE to rAlt a 5 or rHev b 9, one recognizing both allergens. In inhibition studies with the 19 sera displaying IgE to rHev b 9 and rAlt a 5, IgE binding to both allergens with the homologous protein could be weakly inhibited for only one patient. Conclusions Alt a 5 and Hev b 9 showed only very weak cross-reactivity. Nevertheless, the high number of mold allergic people sensitized to Hev b 9 indicates that cross-reactivity is induced by various enolases of other mold sources. Therefore, Hev b 9 should be part of an allergen panel for diagnosis of mold allergy.

The changes in the T helper 1 (Th1) and T helper 2 (Th2) cytokine balance during HIV-1 infection are indicative of an allergic response to viral proteins that may be reversed by Th2 cytokine inhibitors and immune response modifiers--a review and hypothesis.

The HIV-1 infection in humans induces an early cellular immune response to react to the viral proteins with a cytotoxic T cell (CTL) response that fails to inhibit virus replication and the spread of the virus. It became evident that the progression of the disease causes chronic changes to the immune system of which a gradual increase in IgE antibodies is one of its features. When the HIV-1 epidemic began, the relation between the gradual increase in IgE content and AIDS was not understood, but later it became a marker for disease prognosis. The advances in the knowledge on T helper 1 (Th1) and T helper 2 (Th2) cells revealed that Th1 cells produce cytokines that stimulate the proliferation of CTLs. Th2 cells produce cytokines that are responsible for the activation of the humoral immune response in healthy people. Studies on both Th1 and Th2 cytokine synthesis revealed an aberration in HIV-1 infected people. Clerici and Shearer presented a hypothesis (1993) whereby Th1 cell activity declines and Th2 activity increases (the Th1 --> Th2 switch hypothesis) in HIV-1 infected people. In fact, experiments concerning this hypothesis ultimately supported the premise that the switch involves a critical change in the cytokine balance, which leads to the contraction of AIDS. However, the research community must still discern why such a Th1 --> Th2 switch takes place in infected people and how it can be reversed. The present review points to the fact that a similar Th1 --> Th2 switch constitutes the response of allergic people to environmental allergens. HIV-1 patients and allergic people that are exposed to allergens respond with an increased synthesis of Th2 cytokines and IgE, together with a decrease in Th1 cytokines. The studies on allergen-induced Th2 cells revealed that the Th2 cytokine IL-4 induces B cells to synthesize IgE, and cytokine IL-5 is the inducer of eosinophilia, just as in HIV-1 infection. The difference between the HIV-1 infection and allergies is the ability of IL-4 to induce the synthesis in T cells of the HIV-1 coreceptor CXCR4 that selects from the replicating virus a syncytium-inducing (SI) virus, a variant virus that replicates rapidly. The present hypothesis implicates the viral proteins in the induction of Th2 cytokine synthesis. This suggests that in viral proteins, allergen-like domains may be responsible for the activation of Th2 cytokine synthesis. Based on the analogy of the responses of humans to allergens and HIV-1, the following hypotheses is suggested: (a) Removal of allergen-like domains from viral genes by genetic engineering may provide viral proteins for vaccine development. (b) Attempts to treat allergic patients with IL-4 receptor inhibitors suggests that the "Th2 --> Th1 Reversion" constitutes a possible approach to inhibiting the Th2 cytokines and inducing a revival of the anti-viral Th1 response.

Two statistical approaches to forecasting the start and duration of the pollen season of Ambrosia in the area of Lyon (France)

The aim of the present study was to forecast the start and duration of the pollen season of Ambrosia from meteorological data, in order to provide early information to allergists and allergic people. We used the airborne pollen data from Lyon (France), sampled using a Hirst trap from 1987 to 1999, and the meteorological data for the same period: air temperature (minimal, maximal, and average), rainfall, relative humidity, sunshine duration and soil temperature. Two forecasting models were used, one summing the temperatures and the other making use of a multiple regression on 10-day or monthly meteorological parameters. The start of the pollen season was predicted with both methods, results being more accurate with the regression (the errors between the predicted and the observed SDP ranging from 0 to 3 days). The duration of the pollen season was predicted by a regression model, errors ranging from 0 to 7 days. The models were later tested with satisfactory results from 2 additional years (2000 and 2001). Such forecasting models are helpful for allergic people, who have to begin their anti-allergic treatment before the start of the pollen season and not when the symptoms have appeared, since a preventive treatment is more efficient than a curative one. The regression allows predictions to be made 3-5 weeks in advance and so it is of particular interest. The forecasts will be broadcast on the Internet.

Prevalence, severity, and natural history of jack jumper ant venom allergy in Tasmania

Background: The jack jumper ant (Myrmecia pilosula) is responsible for greater than 90% of Australian ant venom allergy. However, deaths have only been recorded in the island of Tasmania. Objectives: We sought to determine the prevalence, clinical features, natural history, and predictors of severity of M pilosula sting allergy in Tasmania. Methods: We performed a random telephone survey supported by serum venom-specific IgE analysis, review of emergency department presentations, and follow-up of allergic volunteers. Results: M pilosula , honeybee (Apis mellifera) , and yellow jacket wasp (Vespula germanica) sting allergy prevalences were 2.7%, 1.4%, and 0.6% compared with annual sting exposure rates of 12%, 7%, and 2%, respectively. Similarly, emergency department presentations with anaphylaxis to M pilosula were double those for honeybee. M pilosula allergy prevalence increased with age of 35 years or greater (odds ratio [OR], 2.4) and bee sting allergy (OR, 16.9). Patients 35 years of age or older had a greater risk of hypotensive reactions (OR, 2.9). Mueller reaction grades correlated well with adrenaline use. During follow-up, 79 (70%) of 113 jack jumper stings caused anaphylaxis. Prior worst reaction severity predicted the likelihood and severity of follow-up reactions; only 3 subjects had more severe reactions. Venom-specific IgE levels and other clinical features, including comorbidities, were not predictive of severity. Conclusions: Sting allergy prevalence is determined by age and exposure rate. M pilosula sting exposure in Tasmania is excessive compared with that found in mainland Australia, and there is a high systemic reaction risk in allergic people on re-sting. Prior worst reaction severity (Mueller grade) and age predict reaction severity and might be used to guide management. (J Allergy Clin Immunol 2003;111:187-92.)