Food allergy is being increasingly recognised with the highest prevalence being in preschool children. Pathogenesis varies so diagnosis rests on careful history and clinical examination, appropriate use of skin prick and serum-specific IgE testing, food challenge, and supervised elimination diets. A double blind placebo controlled food challenge is the gold standard diagnostic test. Avoidance of the allergenic food is the key towards successful management. IgE mediated food allergy may present as a potentially fatal anaphylactic reaction, and management consists of the appropriate use of adrenaline (epinephrine) and supportive measures. Sensitisation remains a key target for intervention. Disease modifying agents are currently under trial for managing difficult allergies. Management requires a multidisciplinary approach and follow up.
Food allergy can present as immediate hypersensitivity [manifestations mediated by immunoglobulin (Ig)E], delayed-type hypersensitivity (reactions associated with specific T lymphocytes), and inflammatory reactions caused by immune complexes. For reasons of ethics and efficacy, investigations in humans to determine sensitization and allergic responses of IgE production to innocuous food proteins are not feasible. Therefore, animal models are used a) to bypass the innate tendency to develop tolerance to food proteins and induce specific IgE antibody of sufficient avidity/affinity to cause sensitization and upon reexposure to induce an allergic response, b) to predict allergenicity of novel proteins using characteristics of known food allergens, and c) to treat food allergy by using immunotherapeutic strategies to alleviate life-threatening reactions. The predominant hypothesis for IgE-mediated food allergy is that there is an adverse reaction to exogenous food proteins or food protein fragments, which escape lumen hydrolysis, and in a polarized helper T cell subset 2 (Th2) environment, immunoglobulin class switching to allergen-specific IgE is generated in the immune system of the gastrointestinal-associated lymphoid tissues. Traditionally, the immunologic characterization and toxicologic studies of small laboratory animals have provided the basis for development of animal models of food allergy; however, the natural allergic response in large animals, which closely mimic allergic diseases in humans, can also be useful as models for investigations involving food allergy.
A diagnosis of food allergies should be made based on the observation of allergic symptoms following the intake of suspected foods and the presence of allergen-specific IgE antibodies. The oral food challenge (OFC) test is the most reliable clinical procedure for diagnosing food allergies. Specific IgE testing of allergen components as well as classical crude allergen extracts helps to make a more specific diagnosis of food allergies. The Japanese Society of Pediatric Allergy and Clinical Immunology issued the 'Japanese Pediatric Guideline for Food Allergy 2012' to provide information regarding the standardized diagnosis and management of food allergies. This review summarizes recent progress in the diagnosis of food allergies, focusing on the use of specific IgE tests and the OFC procedure in accordance with the Japanese guidelines.
Food hypersensitivity; Immunoglobulin E; Oral food challenge
Food allergy is an important public health problem affecting 5% of infants and children in Korea. Food allergy is defined as an immune response triggered by food proteins. Food allergy is highly associated with atopic dermatitis and is one of the most common triggers of potentially fatal anaphylaxis in the community. Sensitization to food allergens can occur in the gastrointestinal tract (class 1 food allergy) or as a consequence of cross reactivity to structurally homologous inhalant allergens (class 2 food allergy). Allergenicity of food is largely determined by structural aspects, including cross-reactivity and reduced or enhanced allergenicity with cooking that convey allergenic characteristics to food. Management of food allergy currently focuses on dietary avoidance of the offending foods, prompt recognition and treatment of allergic reactions, and nutritional support. This review includes definitions and examines the prevalence and management of food allergies and the characteristics of food allergens.
Food allergy; Allergens; Cross reactions; Disease management
Food allergy is defined as an adverse immunologic response to a dietary protein. Food-related reactions are associated with a broad array of signs and symptoms that may involve many bodily systems including the skin, gastrointestinal and respiratory tracts, and cardiovascular system. Food allergy is a leading cause of anaphylaxis and, therefore, referral to an allergist for appropriate and timely diagnosis and treatment is imperative. Diagnosis involves a careful history and diagnostic tests, such as skin prick testing, serum-specific immunoglobulin E (IgE) testing and, if indicated, oral food challenges. Once the diagnosis of food allergy is confirmed, strict elimination of the offending food allergen from the diet is generally necessary. For patients with significant systemic symptoms, the treatment of choice is epinephrine administered by intramuscular injection into the lateral thigh. Although most children “outgrow” allergies to milk, egg, soy and wheat, allergies to peanut, tree nuts, fish and shellfish are often lifelong. This article provides an overview of the epidemiology, pathophysiology, diagnosis, management and prognosis of patients with food allergy.
Food allergies affect 6% of children and 3% to 4% of adults in the United States. Although several studies have examined the prevalence of food allergy, little information is available regarding the prevalence of multiple food allergies. Estimates of prevalence of people allergic to multiple foods is difficult to ascertain because those with allergy to one food may avoid additional foods for concerns related to cross-reactivity, positive tests, or prior reactions, or they may be reluctant to introduce foods known to be common allergens. Diagnosis relies on an accurate history and selective IgE testing. It is important to understand the limitations of the available tests and the role of cross-reactivity between allergens. Allergen avoidance and readily accessible emergency medications are the cornerstones of management. In addition, a multidisciplinary approach to management of individuals with multiple food allergies may be needed, as avoidance of several food groups can have nutritional, developmental, and psychosocial consequences.
Multiple food allergy; IgE; Sensitization; Cross-reactivity; Diagnosis; Allergy management
Food-induced allergic reactions are responsible for a variety of symptoms and disorders involving the skin, gastrointestinal and respiratory tracts and can be attributed to IgE-mediated and non–IgE-mediated (cellular) mechanisms.
Food allergy frequency varies according to age, local diet, and many other factors. The diagnosis of food allergy is based on clinical history, skin prick test (SPT), food specific IgE and more recently atopy patch tests (APT). If needed the use of an oral food challenge to confirm allergy or tolerance.
Describes the case of a patient with multiple manifestations of food allergy after eating habit change.
Man 20 years with a history of food allergy to egg in childhood (at date in remission) asthma and rhinitis and urticaria in contact to cats. He presents an atopic dermatitis, recurrent abdominal pain and diarrhea 18 months after change in eating habits (he became vegetarian). He also presents oral syndrome with cow's milk. The patient had 4 episodes of anaphylaxis post prandial grade 3. In 3 of them the patient ate goat cheese and the other cow cheese. Also 2 of the episodes were associated with exercise. Skin prick tests with goat`s cheese: 13 mm, cow´s milk: 8 mm wheat: 3 mm, corn 3 mm, chicken 3.5 mm, egg yolk: 3.5 mm, avocado and rice 3 mm. Atopy patch test: (+ +) goat`s milk (+) peanuts and coffee. Total IgE 686 IU/mL.
Foods with positive results were excluded from the diet and a complete remission of atopic dermatitis, abdominal pain, diarrhea and anaphylaxis was observed. All foods were reintroduced successfully except milk of goats and cows milk. The patient is currently asymptomatic.
The literature describes different kinds of manifestations of food allergy: immediate hypersensitivity (IgE mediated), delayed hypersensitivity (T lymphocytes mediated) and mixed. Highlights in this case an adult patient with a history of atopy who makes changes in eating habits, developping a food allergy to goat´s and cow s milk, with immediate (anaphylaxis, oral syndrome) and delayed manifestations (atopic dermatitis and chronic diarrhea).
BACKGROUND: The clinical relevance of gastrointestinal food allergy in adults is largely unknown because the mechanisms are poorly understood and the diagnosis is difficult to confirm. AIMS: To improve the diagnostic means for confirming intestinal food allergy on an objective basis, a new colonoscopic allergen provocation (COLAP) test was developed. PATIENTS: The COLAP test was performed in 70 adult patients with abdominal symptoms suspected to be related to food allergy, and in five healthy volunteers. METHODS: During the COLAP test, the caecal mucosa was challenged endoscopically with three food antigen extracts, a buffer control, and a positive control (histamine). The mucosal weal and flare reaction was registered semiquantitatively 20 minutes after challenge, and tissue biopsy specimens were examined for mast cell and eosinophil activation. RESULTS: No severe systemic anaphylactic reactions were found in response to intestinal challenge. The COLAP test was positive to at least one food antigen in 54 of 70 patients (77%), whereas no reaction in response to antigen was found in healthy volunteers. Antigen induced weal and flare reactions were correlated with intestinal mast cell and eosinophil activation, as well as with patients' history of adverse reactions to food, but not with serum concentrations of total or specific IgE or skin test results. CONCLUSION: The COLAP test may be a useful diagnostic measure in patients with suspected intestinal food allergy and may provide a new tool for the study of underlying mechanisms.
Data relating to allergic diseases in general and food allergies in particular in the Central African region is scant. Despite observations by the ISAAC studies that airborne allergen sources were common, little has been reported about food allergens. We reviewed data from our laboratory and outpatient records of patients consulted to estimate the magnitude of the disease in our population.
Patients attending the only specialist allergy diagnostic facility in the country (Asthma, Allergy and Immune Dysfunction Clinic) were offered semi-quantitative allergen specific IgE antibody determination as part of their diagnostic work-up. Alongside skin-prick testing, the Euroimmun immunoblots were used to establish IgE reactivity to a variety of allergen sources.
Six hundred thirty five patients were enrolled between January 2009 and April 2011. These were born between 1931 and 2010. IgE reactivity to egg, codfish, cows milk, wheat flour, rice, soya bean, peanut, hazelnut, carrot, potato and apple was investigated using the immunoblot technique. Results were scored negative or positive. The grades of positive were weak (±), low (+), moderate (++) and high (+++). Overall, 47% of the patients reacted to one or multiple allergen sources. Across the age spectrum, allergen specific IgE reactivity was most frequent against potato (16%) and peanut (15%) and lowest against milk (2.7%) and codfish (2.7%), others were intermediate. Egg white reactivity was highest in those below the age of 5 years (7%). IgE reactivity in patients born before 1959 was less than 1%. This increased to 3.4%, 4.8% and 64% respectively in those born before 1969, 1979 and 1989. Nineteen (19%) of patients born in 1990 to 1999 were reactive to a variety of food allergen sources. Likewise, 12% of those born between 2000 and 2011 were reactive. Food allergen reactivity paralleled inhalant allergen source sensitisation in all age groups.
In this sample of symptomatic patients we have shown that allergen specific IgE reactivity to dietary sources was high. An exponential increase in IgE reactivity in patients born between 1990 and 2011 was a surprising observation. Possible explanations include urbanisation, life-style and dietary changes in this predominantly urban population. The results call for a systematic investigation of the predisposing factors.
Peanut allergy is relatively common, typically permanent, and often severe. Double-blind, placebo-controlled food challenge is considered the gold standard for the diagnosis of food allergy–related disorders. However, the complexity and potential of double-blind, placebo-controlled food challenge to cause life-threatening allergic reactions affects its clinical application. A laboratory test that could accurately diagnose symptomatic peanut allergy would greatly facilitate clinical practice.
We sought to develop an allergy diagnostic method that could correctly predict symptomatic peanut allergy by using peptide microarray immunoassays and bioinformatic methods.
Microarray immunoassays were performed by using the sera from 62 patients (31 with symptomatic peanut allergy and 31 who had outgrown their peanut allergy or were sensitized but were clinically tolerant to peanut). Specific IgE and IgG4 binding to 419 overlapping peptides (15 mers, 3 offset) covering the amino acid sequences of Ara h 1, Ara h 2, and Ara h 3 were measured by using a peptide microarray immunoassay. Bioinformatic methods were applied for data analysis.
Individuals with peanut allergy showed significantly greater IgE binding and broader epitope diversity than did peanut-tolerant individuals. No significant difference in IgG4 binding was found between groups. By using machine learning methods, 4 peptide biomarkers were identified and prediction models that can predict the outcome of double-blind, placebo-controlled food challenges with high accuracy were developed by using a combination of the biomarkers.
In this study, we developed a novel diagnostic approach that can predict peanut allergy with high accuracy by combining the results of a peptide microarray immunoassay and bioinformatic methods. Further studies are needed to validate the efficacy of this assay in clinical practice.
Epitope mapping; peptide microarray; peanut allergy; bioinformatics; machine learning; allergy diagnosis; epitope biomarker
A randomly sampled, cross-sectional serology test-based survey was conducted in Lebanon to describe the pattern of food allergy among Lebanese population. The prevalence of specific Immunoglobulin E (IgE) to food allergens was investigated in 20 laboratories in different regions of Lebanon by an immunoblot assay over a 1 year period. Clinical correlation was determined in two university hospitals. There were 1842 patients with suspected IgE-mediated food allergic reactions tested for specific IgE upon their physician's request. Clinical correlation was done in 93 patients. We identified 386 out of 1842 (20.95%) patients with positive specific IgE to food allergens. The clinical presentations were cutaneous, digestive, and anaphylaxis. The major cause of allergy was cow's milk in infants and young children, hazelnut and wheat flour in adults. Although specific IgE to peanut in infants, children, and adults were higher than for sesame, peanut-induced allergic reactions were mild, in contrary to sesame where anaphylaxis was the only clinical manifestation. Recently, sesame has been recognized as an increasingly frequent and potentially severe allergen. Further studies with double-blind, placebo-controlled food challenge are needed to establish the real prevalence of food allergy in Lebanon, and to determine the most common allergens taking in consideration the nutritional habits of our population.
food allergy; sesame; peanut
Among birch pollen allergic patients up to 70% develop allergic reactions to Bet v 1-homologue food allergens such as Api g 1 (celery) or Dau c 1 (carrot), termed as birch pollen-related food allergy. In most cases, specific immunotherapy with birch pollen extracts does not reduce allergic symptoms to the homologue food allergens. We therefore genetically engineered a multi-allergen chimer and tested if mucosal treatment with this construct could represent a novel approach for prevention of birch pollen-related food allergy.
BALB/c mice were poly-sensitized with a mixture of Bet v 1, Api g 1 and Dau c 1 followed by a sublingual challenge with carrot, celery and birch pollen extracts. For prevention of allergy sensitization an allergen chimer composed of immunodominant T cell epitopes of Api g 1 and Dau c 1 linked to the whole Bet v 1 allergen, was intranasally applied prior to sensitization.
Intranasal pretreatment with the allergen chimer led to significantly decreased antigen-specific IgE-dependent β-hexosaminidase release, but enhanced allergen-specific IgG2a and IgA antibodies. Accordingly, IL-4 levels in spleen cell cultures and IL-5 levels in restimulated spleen and cervical lymph node cell cultures were markedly reduced, while IFN-γ levels were increased. Immunomodulation was associated with increased IL-10, TGF-β and Foxp3 mRNA levels in NALT and Foxp3 in oral mucosal tissues. Treatment with anti-TGF-β, anti-IL10R or anti-CD25 antibodies abrogated the suppression of allergic responses induced by the chimer.
Our results indicate that mucosal application of the allergen chimer led to decreased Th2 immune responses against Bet v 1 and its homologue food allergens Api g 1 and Dau c 1 by regulatory and Th1-biased immune responses. These data suggest that mucosal treatment with a multi-allergen vaccine could be a promising treatment strategy to prevent birch pollen-related food allergy.
Data from many studies have suggested a rise in the prevalence of food allergies during the past 10 to 20 years. Currently, no curative treatments for food allergy exist, and there are no effective means of preventing the disease. Management of food allergy involves strict avoidance of the allergen in the patient's diet and treatment of symptoms as they arise. Because diagnosis and management of the disease can vary between clinical practice settings, the National Institute of Allergy and Infectious Diseases (NIAID) sponsored development of clinical guidelines for the diagnosis and management of food allergy. The guidelines establish consensus and consistency in definitions, diagnostic criteria, and management practices. They also provide concise recommendations on how to diagnose and manage food allergy and treat acute food allergy reactions. The original guidelines encompass practices relevant to patients of all ages, but food allergy presents unique and specific concerns for infants, children, and teenagers. To focus on those concerns, we describe here the guidelines most pertinent to the pediatric population.
food allergy; food hypersensitivity; infants; children; guidelines; anaphylaxis
Food labelling is an important tool that assists people with peanut and tree nut allergies to avoid allergens. Nonetheless, other strategies are also developed and used in food choice decision making. In this paper, we examined the strategies that nut allergic individuals deploy to make safe food choices in addition to a reliance on food labelling.
Three qualitative methods: an accompanied shop, in-depth semi-structured interviews, and the product choice reasoning task – were used with 32 patients that had a clinical history of reactions to peanuts and/or tree nuts consistent with IgE-mediated food allergy. Thematic analysis was applied to the transcribed data.
Three main strategies were identified that informed the risk assessments and food choice practices of nut allergic individuals. These pertained to: (1) qualities of product such as the product category or the country of origin, (2) past experience of consuming a food product, and (3) sensory appreciation of risk. Risk reasoning and risk management behaviours were often contingent on the context and other physiological and socio-psychological needs which often competed with risk considerations.
Understanding and taking into account the complexity of strategies and the influences of contextual factors will allow healthcare practitioners, allergy nutritionists, and caregivers to advise and educate patients more effectively in choosing foods safely. Governmental bodies and policy makers could also benefit from an understanding of these food choice strategies when risk management policies are designed and developed.
The relationships between a history of egg or cows' milk allergy, positive skin tests to these allergens, and atopic illness were examined in a sample of 126 children. Positive skin tests were found more often in children with a history of egg or cows' milk allergy than in children with no such history. 40 children suspected of being allergic to egg or milk, by history or by positive skin tests, were tested by double-blind food challenge. 54 challenges were given to these children, and 26 (49%) were positive. Children suspected of being allergic to egg had a greater incidence of positive challenges than children suspected of having milk allergy. Children with both a present history of food allergy and a positive skin test for that allergen were more likely to have positive challenges than children having only one of these indicators. Most children with positive challenges failed to satisfy Goldman's criterion of a minimum of three positive challenges because of the severity of their reactions. Less stringent criteria are needed for the diagnosis of food allergy in children who are particularly sensitive to food allergens.
Patients with a clinical history of migraine were evaluated psychiatrically, and by electroencephalography. They were challenged with food antigens by skin-prick test, and abdominal symptoms were evaluated following oral ingestion of food allergens. A significant correlation was found between challenge with specific food allergens and the development of migraine headaches, the appearance of abdominal symptoms and the occurrence of positive skin reactions. Psychiatric abnormalities and EEG alterations were associated with the occurrence of headaches and allergic clinical features. It is suggested that the clinical features of migraine can be explained as a result of release of chemical mediators following antigen-antibody reactions in the brain and other tissues where specific antibodies are localized. The continuous ingestion of the responsible food allergens would account for the raised tissue concentrations of noradrenaline, histamine and other mediators to which the clinical features of migraine are attributed.
Eosinophilic Esophagitis (EoE) is an inflammatory disease that reduces the ability of the esophagus to pass food, often leading to dysphagia. A relationship between EoE and food allergies has been determined. However, there have been several documented cases in which patients had negative prick skin testing (PST) results for food allergens and positive results for airborne environmental allergens, and still have a confirmed diagnosis of EoE. Recently, airborne allergens have been implicated in the onset of this condition. Studies have shown that patients sensitive to airborne allergens such as pollen have a seasonal biannual component in which the severity of EoE symptoms increase, coinciding with high pollen seasons.
We followed a 65-year-old man with a history of allergies complaining of an increase in his symptoms of allergic rhinitis and asthma. He also noted dysphagia and occasional vomiting. We noted the disease and medication course over 5 years of treatment.
The patient underwent an esophagogastroduodenoscopy with biopsy, in which midesophageal rings as well as an 8 mm sessile polyp were found, suggesting EoE. Histological analysis confirmed EoE, having found >20 intraepithelial eosinophils/HPF. The patient was treated with a short term prednisone regimen, as well as maintenance medications consisting of inhaled corticosteroids and antihistamines. The patient returned 6 months after the initial consultation and still presented symptoms of EoE, at which point the patient was prescribed proton pump inhibitors. In addition, allergen specific immunotherapy was initiated for confirmed airborne allergens. The patient was examined after 5 years of immunotherapy treatment. Not only did he report that his allergic rhinitis and asthma symptoms were controlled, but his EoE symptoms had resolved.
Results suggest that immunotherapy for airborne allergens could be a successful treatment for EoE. A larger study is needed to determine if allergen specific immunotherapy is a viable treatment option for EoE in similar cases. Such a study could include patients with EoE and confirmed airborne allergies treated with immunotherapy while monitoring a number of eosinophilic and lymphocytic markers.
The popularity of shellfish has been increasing worldwide, with a consequent increase in adverse reactions that can be allergic or toxic. The approximate prevalence of shellfish allergy is estimated at 0.5-2.5% of the general population, depending on degree of consumption by age and geographic regions. The manifestations of shellfish allergy vary widely, but it tends to be more severe than most other food allergens.
Tropomyosin is the major allergen and is responsible for cross-reactivity between members of the shellfish family, particularly among the crustacea. Newly described allergens and subtle differences in the structures of tropomyosin between different species of shellfish could account for the discrepancy between in vitro cross-antigenicity and clinical cross-allergenicity. The diagnosis requires a thorough medical history supported by skin testing or measurement of specific IgE level, and confirmed by appropriate oral challenge testing unless the reaction was life-threatening.
Management of shellfish allergy is basically strict elimination, which in highly allergic subjects may include avoidance of touching or smelling and the availability of self-administered epinephrine. Specific immunotherapy is not currently available and requires the development of safe and effective protocols.
The prevalence of IgE mediated food allergies has increased over the last two decades. Food allergy has been reported to be fatal in highly sensitive individuals. Legumes are important food allergens but their prevalence may vary among different populations. The present study identifies sensitization to common legumes among Indian population, characterizes allergens of kidney bean and establishes its cross reactivity with other legumes.
Patients (n = 355) with history of legume allergy were skin prick tested (SPT) with 10 legumes. Specific IgE (sIgE) and total IgE were estimated in sera by enzyme-linked immunosorbent assay. Characterization of kidney bean allergens and their cross reactivity was investigated by immunobiochemical methods. Identification of major allergens of kidney bean was carried out by mass spectrometry.
Kidney bean exhibited sensitization in 78 (22.0%) patients followed by chickpea 65 (18.0%) and peanut 53 (15%). SPT positive patients depicted significantly elevated sIgE levels against different legumes (r = 0.85, p<0.0001). Sera from 30 kidney bean sensitive individuals exhibited basophil histamine release (16–54%) which significantly correlated with their SPT (r = 0.83, p<0.0001) and sIgE (r = 0.99, p<0.0001). Kidney bean showed eight major allergens of 58, 50, 45, 42, 40, 37, 34 and 18 kDa on immunoblot and required 67.3±2.51 ng of homologous protein for 50% IgE inhibition. Inhibition assays revealed extensive cross reactivity among kidney bean, peanut, black gram and pigeon pea. nLC-MS/MS analysis identified four allergens of kidney bean showing significant matches with known proteins namely lectin (phytohemagglutinin), phaseolin, alpha-amylase inhibitor precursor and group 3 late embryogenesis abundant protein.
Among legumes, kidney bean followed by chick pea and peanut are the major allergic triggers in asthma and rhinitis patients in India. Kidney bean showed eight major allergens and cross reacted with other legumes. A combination of SPT, sIgE and histamine release assay is helpful in allergy diagnosis.
European legislators and wine producers still debate on the requirement for labeling of wines fined with potentially allergenic food proteins (casein, egg white or fish-derived isinglass). We investigated whether wines fined with known concentrations of these proteins have the potential to provoke clinical allergic reactions in relevant patients.
In-house wines were produced for the study, fined with different concentrations of casein (n = 7), egg albumin (n = 1) and isinglass (n = 3). ELISA and PCR kits specific for the respective proteins were used to identify the fining agents. Skin prick tests and basophil activation tests were performed in patients with confirmed IgE-mediated relevant food allergies (n = 24). A wine consumption questionnaire and detailed history on possible reactions to wine was obtained in a multinational cohort of milk, egg or fish allergic patients (n = 53) and patients allergic to irrelevant foods as controls (n = 13).
Fining agents were not detectable in wines with the available laboratory methods. Nevertheless, positive skin prick test reactions and basophil activation to the relevant wines were observed in the majority of patients with allergy to milk, egg or fish, correlating with the concentration of the fining agent. Among patients consuming wine, reported reactions were few and mild and similar with the ones reported from the control group.
Casein, isinglass or egg, remaining in traces in wine after fining, present a very low risk for the respective food allergic consumers. Physician and patient awareness campaigns may be more suitable than generalized labeling to address this issue, as the latter may have negative impact on both non-allergic and allergic consumers.
basophil activation; casein; fining agent; fish allergy; isinglass; milk allergy; questionnaire; skin prick test; wine
Over the past 20 years, food allergy has become an increasingly prevalent international health problem primarily in developed countries. An explanation for this increased prevalence is currently under investigation as it is not well understood. Allergic reactions can result in life threatening anaphylaxis over a short period of time, so the current standard of care dictates strict avoidance of suspected trigger foods and accessibility to injectable epinephrine. Intervention at the time of exposure is considered a rescue therapy rather than a disease modifying treatment. In recent years, investigators have been studying allergen immunotherapy as a way to promote induction of oral tolerance. These efforts have shown some promise towards a viable disease modifying therapy for food allergies. This review will examine the mechanisms of oral tolerance and the breakdown that leads to food allergy, as well as the history and current state of oral and sublingual immunotherapy development.
food allergy; oral tolerance; oral immunotherapy; sublingual immunotherapy
Drug desensitization is the induction, within hours to days, of a temporary state of tolerance to a drug which the patient has developed a hypersensitivity reaction to. It may be used for IgE and non-IgE mediated allergic reactions, and certain non-allergic reactions. The indication for desensitization is where no alternative medications are available for the treatment of that condition, and where the benefits of desensitization outweigh the risks. Desensitization is a therapeutic modality for drug allergy (similar to allergen specific immunotherapy for allergic rhinitis and insect venom anaphylaxis). In contrast, the drug provocation test is a diagnostic modality used to confirm or refute the diagnosis of drug allergy. This review discusses the clinical applications of desensitization for the treatment of common infectious, metabolic and cardiovascular diseases, and oncological conditions in the Asia-Pacific region.
Anaphylaxis; Desensitization; Drug hypersensitivity; Stevens Johnson syndrome; Toxic epidermal necrolysis
Children with food allergies often have concurrent asthma.
The authors aimed to determine the prevalence of asthma in children with food allergies and the association of specific food allergies with asthma.
Parental questionnaire data regarding food allergy, corroborated by allergic sensitization were completed for a cohort of 799 children with food allergies. Multivariate regression analysis tested the association between food allergy and reported asthma.
In this cohort, the prevalence of asthma was 45.6%. After adjusting for each food allergy, environmental allergies, and family history of asthma, children with egg allergy (odds ratio [OR] = 2.0; 95% confidence interval [CI] = 1.3–3.2; P < .01) or tree nut allergy (OR = 2.0; 95% CI = 1.1–3.6; P = .02) had significantly greater odds of report of asthma.
There is a high prevalence of asthma in the food-allergic pediatric population. Egg and tree nut allergy are significantly associated with asthma, independent of other risk factors.
asthma; food allergy; food hypersensitivity; nut allergy; nut hypersensitivity; egg allergy; egg hypersensitivity; pediatrics; allergy; asthma epidemiology
The food labeling system for food allergens was introduced from April 2002 in Japan. To confirm the effectiveness of the system, we regularly conduct a nationwide food allergy survey every 3 years.
The survey was conducted in cooperation with over 1000 volunteer doctors in Japan at 2001+2002, 2005 and 2008. We have sent questionnaires to contributing doctors every 3 months based on the previous survey system, and contributing doctors were asked to report immediate type food allergy cases seen by those doctors. In this survey, immediate type food allergy was defined as the patients who had developed symptoms due to food allergic reaction within 60 minutes after intake of causative foods. The details of questionnaire consisted of age, sex, cause of food allergy, symptoms, antigen-specific IgE, and type of onset.
A total of 8581 immediate type food allergy cases were reported by the doctors in these surveys. The most common causative foods were hen's egg (39.0%), milk products (18.0%), wheat products (9.4%), fruits (5.3%), crustacean (4.6%), peanuts (3.7%), fish egg, buckwheat and fish (3.6%). The most common clinical symptom was observed on skin (89.7%) followed by respiratory system (29.6%). Interestingly, the causes of food allergy were completely different from infancy (egg, milk, and wheat) to adulthood (wheat, crustacean and fruits). Anaphylactic shock was observed in 10.9% of the total reported cases. The cases of anaphylactic shock were due to hen's egg (27.1%), milk products (21.4%) and wheat (18.1%). Eleven percentages of patients had been hospitalized.
We could clarify the detail of the immediate type food allergy cases seen in Japan for a recent decade. Based on these data, countermeasures against food allergy have been conducted in collaboration with the Ministry of Health, Labour, and Welfare in Japan in order to improve quality of life of patients with food allergy.
Peanut-allergic children might be at risk for reactions to other legumes. However, it is not always possible to perform multiple oral food challenges in children. On the basis of patient case history, in vitro diagnostic tests, and eventually food challenges, we aimed at developing an algorithm for risk assessment of possible clinical reactions to other legumes (soybean, lupine, fresh, and blanched green pea). Seventy-five consecutive patients with a positive oral food challenge to peanut were included in the study. All tests were run as part of the routine allergy examination. A high proportion of patients and/or caretakers refused the administered legume oral food challenges. Obtained diagnoses from histamine release did not correlate significantly to the outcome of the algorithm. Interestingly, threshold from peanut challenges did not correlate with the risk assessment.
The algorithm presented in this study can be used when advising peanut-allergic children and their caretakers about what other legumes to avoid in the diet.
cross-reactivity; histamine release; lupine; oral food challenge; pea; peanut allergy; skin prick test; soy; specific IgE