Sicherer, S.H., T.J. Furlong, A. Muñoz-Furlong, A.W. Burks, H.A. Sampson, 2001. A voluntary registry for peanut and tree nut allergy: Characteristics of the first 5149 registrants. J Allergy Clin Immunol. 108:128-132.
Background: A voluntary registry of individuals with peanut and/or tree nut allergy was established in 1997 to learn more about these food allergies. Objective: The purpose of this study was to elucidate a variety of features of peanut and tree nut allergy among the first 5149 registry participants. Methods: The registry was established through use of a structured questionnaire distributed to all members of the Food Allergy and Anaphylaxis Network and to patients by allergists. Parental surrogates completed the forms for children under the age of 18 years. Results: Registrants were primarily children (89% of registrants were younger than 18 years of age; the median age was 5 years), reflecting the membership of the Network. Isolated peanut allergy was reported by 3482 registrants (68%), isolated tree nut allergy by 464 (9%), and allergy to both foods by 1203 (23%). Registrants were more likely to have been born in October, November, or December (odds ratio, 1.2; 95% CI, 1.18-1.23; P < .0001). The median age of reaction to peanut was 14 months, and the median age of reaction to tree nuts was 36 months; these represented the first known exposure for 74% and 68% of registrants, respectively. One half of the reactions involved more than 1 organ system, and more than 75% required treatment, frequently from medical personnel. Registrants with asthma were more likely than those without asthma to have severe reactions (33% vs 21%; P < .0001). In comparison with initial reactions, subsequent reactions due to accidental ingestion were more severe, more common outside the home, and more likely to be treated with epinephrine. Conclusions: Allergic reactions to peanut and tree nut are frequently severe, often occur on the first known exposure, and can become more severe over time.
S.H. Sicherer, 2001. Clinical implications of cross-reactive food allergens. J Allergy Clin Immunol. 108:881-890.
As a consequence of the general increase in allergic sensitization, the prevalence of hypersensitivity reactions to multiple foods that share homologous proteins has become a significant clinical problem. A variety of these allergens conserved among plants (eg, profilin and lipid transfer proteins) and animals (eg, tropomyosin and caseins) have been characterized. Although studies with molecular biologic techniques have elucidated the nature of these ubiquitous allergens, clinical studies have lagged behind. The physician is called on to determine the risk of reaction to related foods among legumes, tree nuts, fish, shellfish, cereal grains, mammalian and avian food products, and a variety of other plant-derived foods that may share proteins with pollens, latex, and each other. Clinical evaluations require a careful history, laboratory evaluation, and in some cases oral food challenges. The pitfalls in the evaluation of food allergy–unreliable histories and limitations in laboratory assessment primarily caused by false-positive skin prick test responses/RAST results are magnified when dealing with cross-reactive proteins. This review focuses on the clinical data regarding cross-reacting food allergens with the goal of providing a background for improved risk assessment and a framework on which to approach these difficult clinical questions.
Kanny, G., D.-A. Moneret-Vautrin, J. Flabbee, E. Beaudouin, M. Morisset, F. Thevenin, 2001. Population study of food allergy in France. J Allergy Clin Immunol. 108:133-140.
Background: Food allergy (FA) is an important health problem for which epidemiologic studies are needed. Objective: We performed an epidemiologic survey in France to determine the prevalence, clinical pictures, allergens, and risk factors of FA. Methods: This study was conducted on 33,110 persons who answered a questionnaire addressed to a representative sample of the French population on a scale of 1:1000 (44,000 subjects aged ≤60 years). One thousand one hundred twenty-nine persons with FA selected during phase 1 received a second questionnaire. Results: The reported prevalence of FA is 3.52%: 3.24% evolutionary FA; 0.12% asymptomatic cases thanks to eviction diets; and 0.17% cured FA. The subjects were characterized by overrepresentation of city dwellers (80% vs 76%), women (63% vs 50%), and health care personnel (11% vs 4%). Fifty seven percent (vs 17%) presented with atopic diseases (P < .01). FA was often persistent, lasting more than 7 years in 91% of the adults. The most frequent allergens were 14% Rosaceae, 9% vegetables, 8% milk, 8% crustaceans, 5% fruit cross-reacting with latex, 4% egg, 3% tree nuts, and 1% peanut. Sensitization to pollen was significantly correlated with angioedema, asthma, rhinitis, and fruit allergy (P < .01). FA was 4 times more frequent in patients with latex allergy. The main manifestations of FA were atopic dermatitis for subjects under 6 years of age, asthma for subjects between 4 and 6 years of age, and anaphylactic shock in adults over 30 years of age (P < .007). Shocks were correlated with alcohol or nonsteroidal anti-inflammatory drug intake (P < .01 and P < .04, respectively). Conclusion: The prevalence of FA is estimated at 3.24% (range, 3.04% to 3.44%) in France. This study emphasizes the increasing risk of FA in well-developed countries and draws attention to certain FA risk factors, such as the intake of drugs (nonsteroidal anti-inflammatory drugs, β-blockers, and angiotensin-converting enzyme inhibitors) or alcohol, intolerance of latex gloves, and socioprofessional status.
Furlong, T.J., J. DeSimone, S.H. Sicherer, 2001. Peanut and tree nut allergic reactions in restaurants and other food establishments. J Allergy Clin Immunol. 108:867-870.
Background: The clinical features of food-allergic reactions in restaurants and other food establishments have not been studied. Of the registrants in the United States Peanut and Tree Nut Allergy Registry (PAR), 13.7% have reported reactions associated with such establishments. Objective: The purpose of this study was to determine the features of allergic reactions to peanut and tree nut in restaurant foods and foods purchased at other private establishments (eg, ice cream shops and bakeries). Methods: Telephone interviews were conducted through use of a structured questionnaire. Subjects/parental surrogates were randomly selected from among the 706 PAR registrants who reported a reaction in a restaurant or other food establishment. Results: Details were obtained for 156 episodes (29 first-time reactions) from 129 subjects/parental surrogates. Most reactions were caused by peanut (67%) or tree nut (24%); for some reactions (9%), the cause was a combination of peanut and another nut or was unknown. Symptoms began at a median of 5 minutes after exposure and were severe in 27% of reactions. Overall, 86% of reactions were treated (antihistamines, 86%; epinephrine, 40%). Establishments commonly cited were Asian food restaurants (19%), ice cream shops (14%), and bakeries/doughnut shops (13%). Among meal courses, desserts were a common cause (43%). Of 106 registrants with previously diagnosed allergy who ordered food specifically for ingestion by the allergic individual, only 45% gave prior notification about the allergy to the establishment. For 83 (78%) of these 106 reactions, someone in the establishment knew that the food contained peanut or tree nut as an ingredient; in 50% of these incidents, the food item was “hidden” (in sauces, dressings, egg rolls, etc), visual identification being prevented. In 23 (22%) of the 106 cases, exposures were reported from contamination caused primarily by shared cooking/serving supplies. In the remaining 21 subjects with previously diagnosed allergy, reactions resulted from ingestion of food not intended for them, ingestion of food selected from buffet/food bars, or skin contact/inhalation (residual food on tables, 2; peanut shells covering floors, 2; being within 2 feet of the cooking of the food, 1). Conclusions: Restaurants and other food establishments pose a number of dangers for peanut- and tree nut–allergic individuals, particularly with respect to cross-contamination and unexpected ingredients in desserts and Asian food. Failure to establish a clear line of communication between patron and establishment is a frequent cause of errors.
Beyer, K., E. Morrow, X.M. Li, L. Bardina, G.A. Bannon, A.W. Burks, H.A. Sampson, 2001. Effects of cooking methods on peanut allergenicity. J Allergy Clin Immunol. 107:1077-1081.
Background: Allergy to peanut is a significant health problem. Interestingly, the prevalence of peanut allergy in China is much lower than that in the United States, despite a high rate of peanut consumption in China. In China, peanuts are commonly fried or boiled, whereas in the United States peanuts are typically dry roasted. Objective: The aim of this study was to examine whether the method of preparing peanuts could be a factor in the disparity of allergy prevalence between the 2 countries. Methods: Two varieties of peanuts grown in the United States were roasted, boiled, or fried. Proteins were analyzed by using SDS-PAGE and immunoblotting. Allergenicity was compared by using immunolabeling with sera from 8 patients with peanut allergy. Results: The protein fractions of both varieties of peanuts were altered to a similar degree by frying or boiling. Compared with roasted peanuts, the relative amount of Ara h 1 was reduced in the fried and boiled preparations, resulting in a significant reduction of IgE-binding intensity. In addition, there was significantly less IgE binding to Ara h 2 and Ara h 3 in fried and boiled peanuts compared with that in roasted peanuts, even though the protein amounts were similar in all 3 preparations. Conclusion: The methods of frying or boiling peanuts, as practiced in China, appear to reduce the allergenicity of peanuts compared with the method of dry roasting practiced widely in the United States. Roasting uses higher temperatures that apparently increase the allergenic property of peanut proteins and may help explain the difference in prevalence of peanut allergy observed in the 2 countries.
Scheibe, B., W. Weissa, F. Ruëff, B. Przybilla, A. Gőrg, 2001. Detection of trace amounts of hidden allergens: hazelnut and almond proteins in chocolate. J Chromatogr B, 756:229–237.
Many patients with immediate type allergy to tree pollen also suffer from intolerance to hazelnuts and almonds. Since rather low levels of hazelnut and almond proteins can provoke an allergic reaction in sensitized individuals, an immunoblot technique has been developed for the detection of potentially allergenic hazelnut and almond proteins in chocolate. Initially, IgE binding hazelnut and almond proteins were detected by immunoprobing with allergic patients’ sera. For routine analysis, patients’ sera were substituted with polyclonal rabbit antisera, and sensitivity was enhanced by the use of a chemiluminescent detection method. This technique allowed the detection of less than 0.5 mg of hazelnut or almond proteins per 100 g of chocolate (=5 ppm). It was applied for routine screening purposes in product quality control as well as for optimization of cleaning steps of filling facilities to minimize cross contamination during production.
Roux, K.H., S.S. Teuber, J.M. Robotham, S.K. Sathe, 2001. Detection and stability of the major almond allergen in foods. J Agric Food Chem. 49:2131-6.
Almond major protein (AMP or amandin), the primary storage protein in almonds, is the major allergen recognized by almond-allergic patients. A rabbit antibody-based inhibition ELISA assay for detecting and quantifying AMP in commercial foods has been developed, and this assay, in conjunction with Western blotting analyses, has been applied to the investigation of the antigenic stability of AMP to harsh food-processing conditions. The ELISA assay detects purified AMP at levels as low as 87 +/-16 ng/mL and can detect almond at between 5 and 37 ppm in the tested foods. The assay was used to quantify AMP in aqueous extracts of various foods that were defatted and spiked with known amounts of purified AMP or almond flour. In addition, AMP was quantified in commercially prepared and processed almond-containing foods. Neither blanching, roasting, nor autoclaving of almonds markedly decreased the detectability of AMP in subsequent aqueous extracts of almonds. Western blots using both rabbit antisera and sera from human almond-allergic patients confirm a general stability of the various peptides that comprise this complex molecule and show that the rabbit antibody-based assay recognizes substantially the same set of peptides as does the IgE in sera from almond-allergic patients.
Rodriguez, J., J.F. Crespo, A. Lopez-Rubio, J. de la Cruz-Bertolo, P. Ferrando-Vivas, R. Vives, P. Daroca, 2000. Clinical cross-reactivity among foods of the Rosaceae family. J Allergy Clin Immunol. 106:183-189.
Background: Foods from the Rosaceae botanical family have been increasingly reported as causes of allergic reaction. Patients frequently have positive skin tests or radioallergosorbent test results for multiple members of this botanical family. Objective: Our purpose was to investigate the clinical cross-reactivity assessed by double-blind, placebo-controlled food challenge (DBPCFC) of Rosaceae foods (apricot, almond, plum, strawberry, apple, peach, and pear). Methods: Thirty-four consecutive adult patients complaining of adverse reactions to Rosaceae were included in the study. Skin prick tests and CAP System (FEIA) were performed with Rosaceae foods in all patients. Clinical reactivity to Rosaceae was systematically evaluated by open food challenges (OFCs), unless there was a convincing history of a recent severe anaphylaxis. Positive reactions on OFCs were subsequently evaluated by DBPCFCs. Results: Twenty-six and 24 patients had positive skin prick tests and CAP FEIA with Rosaceae, respectively; from these 88% and 100% had positive tests with ≥2. No evidence of clinical reactivity was found in 66% percent of positive skin prick tests and 63% of positive specific IgE determinations to fruits. A total of 226 food challenges (including OFC and DBPCFC) were performed in the 28 patients with positive skin prick tests or CAP System FEIA. Of 182 initial OFCs carried out, 26 (14%) reactions were confirmed by DBPCFCs. Overall, 40 reactions were considered positive in 22 patients with positive skin tests or CAP FEIA. Thirty-eight reactions had been previously reported, the remaining two were detected by systematic challenges. Most reactions were caused by peach (22 patients), apple (6), and apricot (5). Ten patients (46%) were clinically allergic to peach and other Rosaceae. Conclusion: Positive skin test and CAP System FEIA should not be taken as the only guide for multi-species dietary restrictions. Nevertheless, the potential clinical allergy to other Rosaceae should not be neglected. If the reported reaction is confirmed, current tolerance to other Rosaceae should be precisely established unless there has been ingestion without symptoms after the reaction.
Sicherer, S.H., H.A. Sampson, 2000. Peanut and tree nut allergy. Curr Opin Pediatr. 12:567–573.
Among foods causing allergic reactions in children, peanut (a legume) and tree nuts (ie, walnut, hazel nut, Brazil nut, pecan) have attracted considerable attention for several reasons. Allergies to these foods are common, frequently have an onset in the first few years of life, generally persist, and account for severe and potentially fatal allergic reactions. Furthermore, the ubiquity of these foods in the diet makes avoidance difficult and accidental ingestions, with reactions, common. This review discusses recent and emerging information on the prevalence, clinical characteristics, natural history, genetic basis, and current treatment of these allergies. In addition, recent advances in the molecular and immunologic characteristics of these allergens, and novel therapeutic options under investigation in animal models, are reviewed.
Rodriguez, J., J.F. Crespo, A. Lopez-Rubio, J. de la Cruz-Bertolo, P. Ferrando-Vivas, R. Vives, P. Daroca, 2000. Clinical cross-reactivity among foods of the Rosaceae family. J Allergy Clin Immunol. 106:183-189.
Background: Foods from the Rosaceae botanical family have been increasingly reported as causes of allergic reaction. Patients frequently have positive skin tests or radioallergosorbent test results for multiple members of this botanical family. Objective: Our purpose was to investigate the clinical crossreactivity assessed by double-blind, placebo-controlled food challenge (DBPCFC) of Rosaceae foods (apricot, almond, plum, strawberry, apple, peach, and pear). Methods: Thirty-four consecutive adult patients complaining of adverse reactions to Rosaceae were included in the study. Skin prick tests and CAP System (FEIA) were performed with Rosaceae foods in all patients. Clinical reactivity to Rosaceae was systematically evaluated by open food challenges (OFCs), unless there was a convincing history of a recent severe anaphylaxis. Positive reactions on OFCs were subsequently evaluated by DBPCFCs. Results: Twenty-six and 24 patients had positive skin prick tests and CAP FEIA with Rosaceae, respectively; from these 88% and 100% had positive tests with ≥2. No evidence of clinical reactivity was found in 66% percent of positive skin prick tests and 63% of positive specific IgE determinations to fruits. A total of 226 food challenges (including OFC and DBPCFC) were performed in the 28 patients with positive skin prick tests or CAP System FEIA. Of 182 initial OFCs carried out, 26 (14%) reactions were confirmed by DBPCFCs. Overall, 40 reactions were considered positive in 22 patients with positive skin tests or CAP FEIA. Thirty-eight reactions had been previously reported, the remaining two were detected by systematic challenges. Most reactions were caused by peach (22 patients), apple (6), and apricot (5). Ten patients (46%) were clinically allergic to peach and other Rosaceae. Conclusion: Positive skin test and CAP System FEIA should not be taken as the only guide for multi-species dietary restrictions. Nevertheless, the potential clinical allergy to other Rosaceae should not be neglected. If the reported reaction is confirmed, current tolerance to other Rosaceae should be precisely established unless there has been ingestion without symptoms after the reaction.
