Food-specific IgE Antibodies Research Articles

Skin Manifestations of Food Allergy

The pediatrician is faced with evaluating a panoply of skin rashes, a subset of which may be induced by food allergy. Acute urticaria is a common manifestation of an allergic skin response to food, but food is rarely a cause of chronic urticaria. Approximately one third of infants/children with moderate to severe atopic dermatitis have food allergy. Although diagnosis of acute urticaria provoked by a food may be evident from a straightforward history and confirmed by diagnostic tests to detect food-specific IgE antibody, determination of the role of food allergy in patients with atopic dermatitis is more difficult and may require additional diagnostic maneuvers, including elimination diets and oral food challenges. The immunopathologic basis of food-allergic disorders that affect the skin and a rational approach to diagnosis and treatment are discussed. Additional disorders that are caused by or mimic ones caused by food allergy are reviewed.

THE PREVALENCE AND DIAGNOSTIC VALUE OF SPECIFIC IgE ANTIBODIES TO INHALANT, ANIMAL AND PLANT FOOD, AND FICUS ALLERGENS IN PATIENTS WITH NATURAL RUBBER LATEX ALLERGY.

Background: It is well recognised that natural rubber latex allergy can be associated with serological crossreactivity to plant allergens, especially tropical fruits and Ficus. In contrast, data on the frequency and clinical value of specific IgE antibodies against these allergens remain rare. In addition, little is known about the prevalence and diagnostic value of specific IgE antibodies to classical inhalant and animal allergens in NRL allergic patients.Objective: The purpose of this study was to investigate the prevalence, the sensitivity, and the specificity of these different specific IgE antibodies in patients suffering from NRL allergy.Methods: Serum samples of 42 NRL allergic adults were investigated. All had a history of NRL allergy confirmed by a positive skin test for latex and a positive latex-specific IgE. Samples were analysed for IgE antibodies against 9 plant food allergens (avocado, banana, chestnut, fig, kiwi, papaya, peanut, pineapple and tomato) and Ficus benjamina. A specific IgE quantification for 3 animal food allergens (codfish, cow’s milk, egg’s white) and 8 common inhalant allergens (Dermatophagoïdes pteronyssinus, birch pollen, timothy grass pollen, mugwort pollen, cat and dog epithelium, Aspergillus fumigatus and Cladosporium herbarum) was also performed. Because double blind placebo-controlled challenges could not be considered, for ethical reasons, patient’s food allergy or immediate hypersensitivity for Ficus and inhalant allergens was documented by a standardised questionnaire. Diagnosis of atopy was based on a relevant history and the presence of a specific IgE antibody to at least one classical inhalant allergen. For some IgE determinations presence or absence of cross-reactivity was investigated by CAPinhibition tests.Results: A specific IgE antibody to at least one of the investigated inhalant and animal food allergens was found in respectively 76% and 12% of the serum samples. A plant food-specific IgE antibody was observed in 88% of the serum samples, most frequently to papaya (71%) and least frequently to kiwi (17%). Twentynine percent of the serum samples contained Ficus-IgE. According to the questionnaire and the threshold of 0.35 kUa/L, sensitivity of the plant food IgE antibodies varied between 0% for papaya and 73% for avocado. Specificity varied between 28% for papaya and 91% for kiwi. For Ficus-IgE sensitivity was 20% and specificity 70%. Conclusions: For inhalant and animal food allergens sensitivity and specificity of the IgE quantification correlated generally well with the values obtained in non- NRL allergic adults. Determination of specific IgE to the investigated plant foods and Ficus was not always a sensitive neither a specific test to establish the clinical diagnosis of this allergy.

The impact of oral food challenges on food-specific IgE antibody concentrations

The impact of oral food challenges on food-specific IgE antibody concentrations

An ELISA-based method for measurement of food-specific IgE antibody in mouse serum: an alternative to the passive cutaneous anaphylaxis assay

Passive cutaneous anaphylaxis (PCA) assay has been a gold standard method to measure allergen-specific IgE antibody (ASIgE Ab) levels in allergy mouse models. Many factors including stringent guidelines for laboratory animal use make PCA a difficult choice. Therefore, alternative methods are needed that can be readily applied for measurement of specific IgE antibody levels in mouse serum. Herein we describe a novel ELISA-based method that is more sensitive in comparison to PCA, IgE isotype-specific (because it has little cross-reactivity with IgG1 or IgG2a isotype) and highly reproducible (<10% inter- or intra-assay variation). Furthermore, we demonstrate the utility of this assay to measure specific IgE Ab against a variety of food extracts including chicken egg, peanut, almond, filbert/hazelnut and sweet potato. These findings are of particular interest to those who are seeking (i) to measure food-extract-specific IgE antibody in animal models and (ii) an alternative to the animal-based PCA method to measure mouse IgE antibodies.

Sensitization to Common Food Allergens Is a Risk Factor for Asthma in Young Chinese Children in Hong Kong

Sensitization to aeroallergens is a major risk factor for asthma. Although patients frequently consider food ingestion as an asthma trigger, the relationship between serum food-specific IgE antibodies and childhood asthma in China remains unclear. We therefore conducted a case–control study on asthmatic children attending a university hospital-based outpatient clinic to investigate their pattern of food sensitization. Asthmatic patients underwent spirometric assessment, and peripheral blood was collected for serum-specific IgE antibodies to common food and inhalant allergens. Two hundred and thirty-one asthmatics (aged 9.3±4.3 years) and 79 age- and sex-matched controls were enrolled. The serum logarithmic total IgE concentrations in patients and controls were 2.49 and 1.92, respectively (p<0.0001). Subjects with increased serum total IgE level were significantly more likely to have food sensitization than those with normal values (33% vs. 16%; p = 0.001). Twenty-nine (52%) of 56 asthmatics younger than 6 years old and seven (27%) of 26 age-matched controls had food-specific IgE in their sera (p = 0.035). Asthmatics with food-specific IgE also used more doses of as-needed bronchodilator weekly (p = 0.005). Nonetheless, no association was found between asthma diagnosis and sensitization to individual food allergens. Significant food sensitization, with food-specific IgE level above 95% predictive values for clinical food allergy as proposed by Sampson, was only found in two patients for peanut and three subjects for egg white. In conclusion, a significant association was found between asthma and the presence of food-specific IgE antibodies in young Chinese children. Significant sensitization to common foods is rare in this cohort.

Duodenal IgE-positive cells and elimination diet responsiveness in children with atopic dermatitis

Parameters for identifying eczematous children who could respond to an elimination diet are needed. In children with food allergy, duodenal IgE-containing cells are enhanced. To determine the presence of duodenal mucosal IgE-positive cells in atopic dermatitis and to determine whether duodenal IgE-positive cells may identify eczematous children who will benefit from an elimination diet. Thirty-one children with severe eczema underwent gastrointestinal endoscopy because of gastrointestinal symptoms and were treated with an elimination diet. A clinical score to skin lesions was given before and after diet. All subjects were skin-prick tested with food antigens and aeroallergens. Serum IgE levels were measured. Duodenal IgE-positive cells were investigated in 18 control subjects and in all eczematous children before diet. The number of duodenal IgE-positive cells in children with atopic dermatitis was significantly increased compared with that of control group (P < 0.001). Nineteen (61%) eczematous children improved on a few food diet. Diet-responsive children had significantly higher IgE-positive cells compared with both nondiet-responsive and controls. Positive predictive accuracy of duodenal IgE-positive cells was poor, whereas negative predictive accuracy was high at the cutoff level of 50 IgE-positive cells/10 visual fields. Diagnostic accuracy both of SPT reactions with foods and of food-specific serum IgE antibodies was poor. An intestinal IgE-mediated reaction occurred in children with severe atopic dermatitis who underwent intestinal endoscopy because of gastrointestinal symptoms. In these eczematous children, the number of IgE-positive cells in the duodenal mucosa might be helpful for excluding a positive response to the elimination diet.

Utility of food-specific IgE concentrations in predicting symptomatic food allergy

Background: The double-blind, placebo-controlled food challenge is considered the gold standard for diagnosing food allergy. However, in a retrospective analysis of children and adolescents with atopic dermatitis and food allergy, discrete food-specific IgE concentrations were established that could predict clinical reactivity to egg, milk, peanut, and fish with greater than 95% certainty. Objective: The purpose of this investigation was to determine the utility of these 95% predictive decision points in a prospective evaluation of food allergy. Methods: Sera from 100 consecutive children and adolescents referred for evaluation of food allergy were analyzed for specific IgE antibodies to egg, milk, peanut, soy, wheat, and fish by using the Pharmacia CAP System FEIA. Food-specific IgE values were compared with history and the results of skin prick tests and food challenges to determine the efficacy of previously established 95% predictive decision points in identifying patients with increased probability of reacting during a specific food challenge. Results: One hundred children (62% male; median age, 3.8 years; range, 0.4-14.3 years) were evaluated for food allergy. The diagnosis of food allergy was established by means of history or oral food challenge. On the basis of the previously established 95% predictive decision points for egg, milk, peanut, and fish allergy, greater than 95% of food allergies diagnosed in this prospective study were correctly identified by quantifying serum food-specific IgE concentrations. Conclusion: In a prospective study of children and adolescents referred for evaluation of food allergy, previously established 95% predictive decision points of food-specific IgE antibody concentrations for 4 major food allergens were effective in predicting clinical reactivity. Quantification of food-specific IgE is a useful test for diagnosing symptomatic allergy to egg, milk, peanut, and fish in the pediatric population and could eliminate the need to perform double-blind, placebo-controlled food challenges in a significant number of children. (J Allergy Clin Immunol 2001;107:891-6.)

Markers for early sensitization and inflammation in relation to clinical manifestations of atopic disease up to 2 years of age in 133 high-risk children.

The combination of genetic susceptibility and environmental factors induce allergic sensitization and subsequently local inflammation, resulting in atopic manifestations. To examine whether immunological features reflecting sensitization (total and specific IgE levels, allergen-induced proliferative responses and skin tests) and markers of inflammation (plasma sE-selectin and blood eosinophils) are related to the clinical expression of atopy and whether they precede atopic disease in children up to 2 years of age. The development of these markers during the first 2 years of life was studied prospectively in 133 newborns at high risk to develop atopic disease. The prevalence of atopic disease increased from 25% at 12 months to 32% at 24 months of age. The children with food allergy at 12 months, who all had atopic dermatitis (AD), turned out to have asthma-like disease in 40% and AD in 100% at the age of 24 months. Total IgE levels increased with time and from 12 months onward levels started to differ markedly between atopics and nonatopics. Food-specific IgE antibodies were significantly associated with AD (relative risk [RR] = 2.39), food (RR = 1.32) and upper-airway allergy (RR = 1.20), and house dust mite-specific IgE antibodies with upper-airway allergy (RR = 5.00). A positive skin test was significantly associated with AD (RR = 2.90) and food allergy (RR = 1.36). The inflammation markers investigated, were not related to the clinical expression or preceded atopic disease at 2 years of age in high-risk children. Positive skin tests and specific IgE to food or inhalant allergens were related to the clinical expression of different atopic diseases. The combination of AD and food allergy at 12 months reflected the strongest risk factor in this high risk cohort for the development of asthma-like disease at 24 months of age.

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. (J Allergy Clin Immunol 2000;105:1077-84.)

Dose-response in double-blind, placebo-controlled oral food challenges in children with atopic dermatitis

Background: Double-blind, placebo-controlled oral food challenges (DBPCFCs) are considered the “gold standard” for diagnosing food hypersensitivity, but the dose that elicits positive challenges, or determinants that may predict dose-response relationships, have not been reported. Objective: Our purpose was to determine the quantity of food that elicits reactions during DBPCFCs and to evaluate parameters that may predict the provocative dose and severity of reaction. Methods: We reviewed challenge data for all positive challenges to 6 common allergenic foods in children with atopic dermatitis evaluated for food allergy over a 13-year period. Challenge food was generally administered in 6 doses at 10- to 15-minute intervals beginning with 400 to 500 mg and completing with a total of 8 to 10 g of food. An open feeding of a larger portion followed negative challenges. At the physician’s discretion, a lower starting dose was occasionally used (100 mg, 250 mg). Food-specific IgE antibody concentrations (radioallergosorbent test [RAST]) were determined on stored sera of 20% of the challenges selected randomly and 99.6% had prick skin tests (PSTs) performed to the challenged food. Results: A total of 196 children (45% male; median age 5 y 9 mo; atopic dermatitis 98%, asthma 62%) had 513 positive challenges distributed as follows: egg 267, milk 117, soy 53, wheat 40, peanut 24, fish 12. The percentage of children reacting at the first dose (500 mg or less) was as follows: egg 49%, milk 55%, soy 28%, wheat 25%, peanut 26%, and fish 17%. Twenty-six milk challenges and 22 egg challenges were positive at a first dose of 250 mg; 3 milk challenges and 7 egg challenges were positive at a first dose of 100 mg. Eleven percent of the reactions that occurred on the first dose were severe. The percentage reacting after the final dose of the DBPCFC (or during open challenge) were egg 11%, milk 12%, soy 19%, wheat 12.5%, peanut 8.7%, and fish 25%. There was not a strong correlation between PST absolute wheal size or score (adjusted for histamine controls) and dose at reaction or severity of reaction (Rs range –0.22 to 0.39 for particular foods). Serum concentration of food-specific IgE did not correlate well with the dose causing a reaction or with severity (Rs range –0.40 to 0.55 for particular foods). Conclusions: This food-allergic population may react to as little as 100 mg of food, possibly less, and the dose causing a reaction and the severity of reaction is not predicted by PST or RAST. Lower doses (100 mg or less) should be investigated for their appropriateness in initiating DBPCFCs. (J Allergy Clin Immunol 2000;105:582-6.)

DIAGNOSIS AND MANAGEMENT OF FOOD HYPERSENSITIVITY

Physicians and other healthcare professionals are regularly confronted by patients with numerous signs and symptoms related to the upper and lower respiratory tract, skin, and gastrointestinal tract. After frustration with multiple medication courses or with the patient's or parent's initiative, the question may arise as to whether food allergies are contributing to the problems. Confusion over what constitutes food allergy exists in the medical community as well as in the public. This article clarifies terminology and discusses common presentations, diagnosis, and practical management of food allergy. The term food allergy is often used loosely and incorrectly by physicians, the public, and the media. An accurate general term to describe any abnormal reaction to a food or food additive is adverse food reaction . 14 Adverse food reactions can be the result of food intolerance or food hypersensitivity. 2 Food intolerance accounts for a majority of adverse food reactions and is not immune-mediated. Examples include toxic food poisoning (vomiting and diarrhea from ingestion of staphylococcal or salmonella toxins), pharmacologic effects (jitteriness from caffeine in a cola beverage), and metabolic disorders (bloating and flatus from lactase deficiency). The terms food allergy or food hypersensitivity should be reserved to define an immunologically mediated adverse food reaction. The classic food hypersensitivity reaction is mediated via food-specific IgE-antibodies and, in the most dramatic case, can lead to food-induced anaphylaxis. The other group of food hypersensitivity reactions are non-IgE mediated but involve other immunologic reactions and primarily manifest gastrointestinally. Examples include food-induced enteropathies, such as celiac disease with its characteristic elevated IgA anti-gliadin antibodies. 19

Relationship between food-specific IgE concentrations and the risk of positive food challenges in children and adolescents

Background: The double-blind, placebo-controlled food challenge (DBPCFC) is the “gold standard” for diagnosis of food hypersensitivity. Skin prick tests and RASTs are sensitive indicators of food-specific IgE antibodies but poor predictors of clinical reactivity. Previous studies suggested that high concentrations of food-specific IgE antibody were predictive of food-induced clinical symptoms. Because the CAP System FEIA (Pharmacia Diagnostics, Uppsala, Sweden) provides a quantitative assessment of allergen-specific IgE antibody, this study was undertaken to determine the potential utility of the CAP System FEIA in diagnosis of IgE-mediated food hypersensitivity. Methods: Sera from 196 patients with food allergy were analyzed for specific IgE antibodies to egg, milk, peanut, soy, wheat, and fish by CAP System FEIA. Sera were randomly selected from 300 stored samples of children and adolescents who had been evaluated by history, skin prick tests, and DBPCFCs. The study population was highly atopic; all patients had atopic dermatitis, and approximately 50% had asthma and allergic rhinitis at the time of initial evaluation. The performance characteristics of the CAP System FEIA were compared with those of skin prick tests and the outcome of DBPCFCs or “convincing” histories of anaphylactic reactions. Results: The prevalence of specific food allergies in the study population varied from 22% for wheat to 73% for egg. Allergy to egg, milk, peanut, and soy accounted for 87% of confirmed reactions. The performance characteristics of skin prick tests and CAP System FEIA (egg, milk, peanut, fish) were comparable, with excellent sensitivity and negative predictive accuracy but poor specificity and positive predictive accuracy. The performance characteristics of the CAP System FEIA for soy and wheat were poor. For egg, milk, peanut, and fish allergy, diagnostic levels of IgE, which could predict clinical reactivity in this population with greater than 95% certainty, were identified: egg, 6 kilounits of allergen-specific IgE per liter (kU A/L); milk, 32 kU A/L; peanut, 15 kU A/L; and fish, 20 kU A/L. Conclusions: When compared with the outcome of DBPCFCs, results of CAP System FEIA are generally comparable to those of skin prick tests in predicting symptomatic food hypersensitivity. Furthermore, by measuring the concentrations of food-specific IgE antibodies with the CAP System FEIA, it is possible to identify a subset of patients who are highly likely (>95%) to experience clinical reactions to egg, milk, peanut, or fish. This could eliminate the need to perform DBPCFCs in a significant number of patients suspected of having IgE-mediated food allergy. (J Allergy Clin Immunol 1997;100:444-51.)

Identification of food specific IgE-antibodies in patients with chronic diarrhea by intestinal lavage

Identification of food specific IgE-antibodies in patients with chronic diarrhea by intestinal lavage

Effect of elimination diets on food-specific IgE antibodies and lymphocyte proliferative responses to food antigens in atopic dermatitis patients exhibiting sensitivity to food allergens

Peripheral blood mononuclear cells (PBMCs) from patients with atopic dermatitis (AD) selected as being sensitive to hen's egg or cow's milk responded to food antigens, ovalbumin, or bovine serum albumin, with significantly enhanced DNA synthesis compared with the DNA synthesis in PBMCs from nonatopic control subjects and food-sensitive patients with immediate symptoms. Patients were treated with elimination diets. Symptoms of AD had been in remission during elimination diets. The levels of specific IgE antibodies to hen's egg or cow's milk decreased during elimination diets in patients with positive radioallergosorbent test (RAST). In patients with negative RAST, specific IgE antibodies remained negative during elimination diets. The proliferative responses of PBMCs to food antigens also decreased during elimination diets in patients with proliferative responses before elimination diets. Taken together, specific IgE antibodies to food antigens are useful indexes of the effect of elimination diets in food-sensitive patients with AD and positive BAST, and proliferative responses of PBMCs to food antigens are useful indexes of the effect of elimination diets in food-sensitive patients with AD and proliferative responses of PBMCs. (J ALLERGY CLIN IMMUNOL 1993;91:668-79.)

Evaluation of a multiple food specific IgE antibody test

Clinical & Experimental AllergyVolume 22, Issue 8 p. 804-804 Evaluation of a multiple food specific IgE antibody test B. R. Adler, B. R. Adler Department of Paediatrics, St Mary's Hospital, London W2 IN7, U.K.Search for more papers by this authorJ. O. Warner, J. O. Warner Department of Child Health, Southampton University, Southampton General Hospital, Tremona Road, Southampton S09 4XY, U.K.Search for more papers by this author B. R. Adler, B. R. Adler Department of Paediatrics, St Mary's Hospital, London W2 IN7, U.K.Search for more papers by this authorJ. O. Warner, J. O. Warner Department of Child Health, Southampton University, Southampton General Hospital, Tremona Road, Southampton S09 4XY, U.K.Search for more papers by this author First published: August 1992 https://doi.org/10.1111/j.1365-2222.1992.tb02822.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume22, Issue8August 1992Pages 804-804 RelatedInformation

Evaluation of a multiple food specific IgE antibody test compared to parental perception, allergy skin tests and RAST

This study was set up to evaluate the food panel of a multiple specific IgE antibody assay in 67 atopic asthmatic children by comparing it to the conventional radioallergosorbent test (RAST) and skin-prick tests (SPT) and then comparing the results of these investigations with the parents' perceptions of food related problems. Fifteen food specific IgE antibodies were measured using the multiple chemiluminescence assay (MAST-CLA). IgE antibodies to five of these food allergens were also measured by conventional RAST and SPTs were performed in 43 using 11 standardized food extracts matched to the multiple allergosorbent chemiluminescent assay (MAST-CLA) profile. SPT and MAST-CLA results showed good agreement with one another, range 68.8-96.7% (average 87%), with significant correlation for most allergens tested. MAST-CLA was discrepant with RAST and/or SPTs in 58/210 (27.6%). A questionnaire was sent to the parents to determine their perception of food related symptoms. Sixty-two (92%) questionnaire replies were received, of which 56% reported symptoms with food. The most frequent symptom perceived to be due to food intolerance was behavioural disturbance. The commonest foods implicated were additives (39%), egg (27%), milk (26%), chocolate (23%) and orange (15%). History, SPT, MAST-CLA and RAST were compared for five allergens in 42 patients (210 values). In 14/210 (6.7%), all the tests were negative despite reported symptoms. Conversely in 49/210 (23.3%) at least one test was positive without symptoms. This study did not support a benefit of multipole testing instead of individually selected RASTs or SPTs.(ABSTRACT TRUNCATED AT 250 WORDS)

Food-Induced Anaphylaxis

Food-induced anaphylaxis is most frequently caused by proteins in peanut, fish, tree nuts, crustaceans, milk, egg, or soy; in many instances, the individual allergens have been isolated and characterized. Although persons sensitized to one food are often advised not to eat other foods from the same food family, recent studies using DBPCFC feedings suggest that clinically significant cross-allergenicity among legumes and among fish may be less common than formerly suspected. Cow’s milk allergy in infants may disappear spontaneously with time, but sensitivity to peanut, fish, or nuts is usually long-lasting. Newer hypoallergenic formulas prepared from casein or whey hydrolysates are not completely allergen-free and may pose risks to infants highly sensitive to cow’s milk. The diagnosis of food-induced anaphylaxis is made from the clinical history and can be confirmed by puncture skin testing or by in vitro demonstration of food-specific IgE antibodies. Immunoassays have been developed for "hidden" or contaminating allergens that are not listed on food product labels. The drug of choice for treatment of food-induced anaphylaxis is subcutaneous epinephrine, and sensitive persons should carry epinephrine and be familiar with its use. Most cases of fatal food-induced anaphylaxis occur away from home, and food-sensitive persons need to develop an anticipatory action plan to deal with reactions that occur at work, at school, or in distant communities. The number of anaphylaxis fatalities could be reduced by better patient education, better food labeling, and a greater awareness of food allergy by restaurant service personnel and paramedical rescue teams.

SYSTEMIC AND OTHER SYSTEM DISORDERS

Purpose of Study The purpose of this paper was to report clinical and laboratory findings from seven cases of fatal anaphylaxis due to foods. Study Population The report was based on the findings from seven patients ranging from 11 to 43 years of age: two female and five male patients. The cases were evaluated over a 16-month period. Methods Serum samples were obtained from six of the seven cases during resuscitation attempts or at autopsy. Food-specific IgE antibodies were measured by solid-phase radioimmunoassay. Findings Elevated levels of IgE antibodies to the incriminated foods were present in the six cases where the serum was available for study. Three were due to peanut and one each were due to pecan, crab, and cod. The seventh case (without serum) was due to peanut. The patients had some features in common: Most were highly atopic; most reactions occurred away from home; all had previously had generalized immediate reactions to the food; and none were on β-adrenergic blocking agents. Several recommendations are made by the authors. Patients and physicians must be made aware of the potential consequences of severe systemic reactions to foods. Patients and physicians must know that the immediate treatment is injectable, aqueous adrenalin not oral antihistamines, nor epinephrine by metered-dose aerosol or in suspension. The patients should have the adrenalin available to them at all times and know how to administer it. Patients receiving concomitant steroid therapy should be assumed to have adrenal suppression and treated appropriately during resuscitation. Ingredients of prepared foods must be made available and patients (and/or their families) must use this information to try to avoid catastrophic results.