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551 Pattern of food hypersensitivity over a decade of over food challenges in children with atopic dermatitis
S182
Abstracts
J ALLERGY CLIN IMMUNOL JANUARY
549
550
Allergic
Reactions
Wegrzyn*.
Heidi
School Anna Nowok*John Hopkins University School of Medicine, Eudowood Division of Pediatric Allergy and Immunology, Baltimore, MD tuniversity of Maryland Medical Systems, Department of Pediatrics, Baltimore, MD Accidental ingestions are common in children with food allergies. We phone-surveyed parents of 50 patients (median age 6.9, range: 3.2-19.3 years) with food allergies seen in our clinic from April to August 1999 in order to better characterize their reactions to foods at school. 8 children were home schooled, 7 due to food allergy. Of the remaining 42 children, 67% attended school. 33% preschool. 48% were allergic lo four or more, 29% to three, 14% lo one, and 9% to two foods. 24 (57%) children had 65 accidental ingestions in the past 2 years. including I6 reactions in 9 children that occurred at school (63% elementary, 33% preschool). Parents were unable lo identify the food in 7 reactions, peanut and milk were implicated in 3 reactions each, egg in 2, and celery in I reaction. 5 reactions occurred in classrooms with eating areas, 4 in regular classrooms, 2 both in the cafateria and playground. The location could not be identified in 3 reactions. Symptoms included: hives-8, wheezing-4, pruritus-3, vomiting/diarrhea-3, facial angioedema-2, and contact skin rash- I reaction. Treatment included: oral antihistamines-12, epinephrine and bronchodilalors in 2 each, and treatment was not specified in I reaction. I1 reactions were treated by a nurse. 2 by a teacher, 1 by EMTs, I by mother, and in I the person was not identified. 8 I % of reactions were treated within IO minutes. Paren& provided schools with protocols and medications for treatment of acute allergic reactions in 91% and 93% of children respectively. The medications were kept in the nurse’s office in 46%. with the teacher in 23%. in child’s bag in l8%, and in the front office in 15%. 69% of parents provided all meals for their children, 3 I % allowed selected foods. 4 I % of children ate their meals in the classroom, 38% in school cafeteria, 5% at a restricted table, 2% in the nurse’s office, and 2% did not eat at school at all. We contacted 24 of the schools which the children attended (54% private. 46% public). There were median 5 children with food allergies per school (range l-25). 5 allergic reactions to foods in the past two years were reported in 4 schools (3 elementary, one preschool). 50% of schools utilized their routine medication forms for instructions for treatment of allergic reactions, whereas 50% used specific forms. 7 I % of schools reported special accommmodations for children with food allergies: restricted peanuts from the classroom-25%. alternative meals-21 %, separate eating areas- 175, peanut-free tables in the cafeteria-l%, other- 17%. CONCLUSIONS: 38% of children who had had accidental ingestions in the past 2 years experienced at least one acute reaction to food at school. Reactions at schools accounted for 25% of all reactions encountered within past 2 years. Although each of the reactions was successfully treated, there was no protocol or medications available for 9% and 7% of all children respectively. Peanut
Allergic
to
Isenbergf,
Foods
Robert
parental surrogates described 124 school reactions to peanut (I 15) or tree nuts (9). Physicians had verified the food allergy for 99% of the subjects and 85% had specific IgE tests performed, all were positive. Sixty-four percent of the reactions occurred in daycare or preschool, the remainder in elementary school or higher. Among those in elementary school, 68% were public schools. In 25% of the cases, the school reaction was their first indication of peanut allergy. Reactions resulted from ingestion (60%). skin contact (24%) and inhalation (15%). However, in the majority of reactions due to inhalation, concomitant ingestion/skin contact could not be ruledout. Peanut butter craft projects were commonly responsible for the skin contact (60%) or inhalation (44%) reactions. Reactions often occurred during parties/special occasions (24%). In 24 instances, the reaction symptoms were not noted until the parent observed the child. usually at the end of the school day. Symptoms were severe in 24% of reactions. For 90% of the reactions, medications were given (86% received antihistamines. 33% epinephrine). For 57% of those treated, parents administered the medication either after being summoned to the school (63%) or because they were the first to notice a reaction. Overall, 53% of the medications were given in the school building, including epinephrine in I9 cases. Teachers gave epinephrine in 4 cases, nurses in 6, and parents or other personnel in the remainder. Among patients with previously identified allergy requiring. but not receiving, medicine in school (36 cases), a variety of reasons were given including, reaction not initially noticed, parents called to pick child up, and unable to activate epinephrine. Among school personnel, the teachers were most likely lo take control of Ihe incidents (77% had no school nurse present). An emergency plan was in place for 33% of the reactions but was followed correctly 73% of the time. Three reactions occurred despite a peanut “ban”. A number of responses were taken after the reaction including home meal preparation, educational efforts directed to staff and students, allergy free tables and classroom peanut bans. In conclusion, school peanut-allergic reactions can be severe and frequently require medical treatment; school personnel must be educated to recognize the signs of a reaction, to treat symptoms promptly and appropriately and to avoid accidental exposures, including exposure from peanut butter craft projects
in the
A. Wood*
Reactions in Schools TJ Furlong*. J DeSimone*, *Food Allergy Network, Fairfax VA tMount Sinai School of Medicine, New York, NY It is not uncommon for food allergic reactions to occur in schools, but the clinical features of these reactions have not been well described. Using a standard questionnaire, we conducted 100 telephone interviews of parental surrogates from among a random sampling of registrants in the National Peanut and Tree Nut Allergy Registry who indicated allergic reaction(s) in school. The 100
SH Sichererf
2000
551
Pattern of Food Hypersensitivity Challenges in Children with Chatcharee,
HA
Sampson,
Over a Decade of Oral Food Atopic Dermatitis LK El/man, P SH Sicherer Mount Sinai School of
Medicine, New York, NY There is a clinical impression that food allergy has become more prevalent in terms of the number of foods to which allergies occur and sensitization rates. However, formal studies regarding patterns of food allergy over time are lacking. Through chart review, we compared children with atopic dermatitis referred lo our clinical research center for evaluation of food hypersensitivity by oral food challenges a decade ago (Group “A”- 5/88 to 6/89) to those evaluated in the past year (Group “B”- 5/98 to 6/99). There were 43 children in group A (mean age 7.8 years, 47% with asthma) and 32 in group B (mean age 8.2 years, 62% with asthma). A total of 138 oral food challenges were performed in Group A and 78 in group B. “Major” food allergens have typically been considered cow’s milk, egg. wheat, soy, peanut, nuts, fish and shellfish. These major food allergens accounted for 7 I % of the challenges performed in group A, but only 58% of the challenges in group B (chi-square p < 0.001). The reduction in challenges to these major food allergens was influenced by decisions not lo challenge based upon food-spe-
Abstracts
J ALLERGY CLIN IMMUNOL VOLUME 105, NUMBER 1. PART 2
citic IgE (F-IgE; Pharmacia CAP-RAST FEIA) antibody levels indicating a high risk (995%) for reactions [Sampson & Ho JACI 1997;100:444] primarily among those eliminating, but not challenged to egg and milk. The overall proportion of positive challenges to major food allergens was 40% in each group and was significantly higher (Chi square p = 0.007) than the proportion of positive challenges to “minor” foods (group A- 15%. group B- 12%). Considering both groups, the minor food allergens that elicited positive oral challenges (positive/total tested) included barley-112, corn-l/9, beef- 4/10, pork-115 tomato-2/6, and mustard-l/l. ChaIlenges were negative to 21 other foods. The proportion of positive challenges caused by the major allergens was not significantly different (p=O.6) between group A (87%) and group B (82%; or 91% with inclusion of positive predictive F-IgE to egg, milk). More detailed analysis was performed for egg, cow’s milk and soy since 07 challenges were performed in each group. Among those eliminating these foods, the proportion with a positive challenge or a high F-IgE was greater between group A and B only for cow’s milk (34% to 70%, respectively, p = 0.006). Sensitization (wheal > 3 mm mean diameter, F-IgE > 0.7 kU/L) to milk, egg, wheat, soy and peanut were not significantly different between groups (overall sensitization 74% in group A and 79% in group B). In conclusion, these data suggest the following: that allergy to “minor” foods has not increased, that most clinical reactivity 080%) is accounted for by a few “major” food allergens, that clinical reactions to cow’s milk have increased, and that sensitization rates remained stable in these referral populations over the past decade. 552
A Neonatal Pig Model for Peanut Allergy RM Helm, G Cockrell, C Connaughton, GA Bannon. AW Buds Our in vitro results over the last ten years have identified several peanut proteins, Ara h 1.2, and 3 that are the major allergens contributing to the hypersensitivity responses in humans. Based on these studies, we proposed to develop an animal model that will further enable us to investigate the IgE-mediated gastrointestinal allergic response to foods. The similarities in digestive function in the neonatal pig and man make this an attractive model to improve our knowledge of gastrointestinal hypersensitivity to peanuts. Pregnant sows at day 109 of gestation were fed an NRC-approved sow lactation diet consisting of a soybean/peanut-free diet throughout lactation. Newborn piglets were allowed to suckle ad libitum for three weeks and then weaned to nursery diets lacking soybean/peanut proteins meeting NRC regulations at three, seven, and thirteen weeks, respectively. Three-day old piglets were divided into three groups and either intragastrically (i.g.) or intraperitoneally (i.p.) sensitized with crude peanut meal as follows: Group 1: 2 grams peanut meal in phosphate buffered saline (PBS) i.g. on day 3,4, and 5 with lOOpI cholera toxin (Ctx): Group 2: 2 grams of peanut meal in PBS i.g. on day 9, IO. and I I with lOOpI Ctx; and Group 3: 5OOpg peanut meal in PBS on day 3, 4. and 5 i.p. with lOOpI Ctx. Each group was subsequently boosted I week later with the respective peanut sensitization protocol. Three weeks following sensitization, intragastric challenge with 10 grams of peanut meal in PBS resulted in symptoms ranging from erythematous rashes, cyanosis about the snout and ears, lethargy, vomiting, and respiratory distress in 25% of the piglets sensitized to peanut meal. Control animals challenged with IO grams of peanut meal did not respond with any
SlB3
of the symptoms associated with peanut-sensitized animals. Skin test results with peanut extract one week later showed wheal and erythema skin test reactions typical of immediate type allergen skin tests in sensitized piglets with no response in control animals. In conclusion, we have preliminary evidence that we can successfully mimick the gastrointestinal food allergy response in neonatally peanut-sensitized piglets. Dosage and sensitization/challenge protocols are under further investigation to increase our success rate for the pig model of gastrointestinal hypersensitivity. 553
Rye y-Secalin and Barley y-HordeIn Are Cross-reactive Allergens in Wheat-dependent, Exercise-induced Anaphylaxis K Palosuo*f, H Aleniusf. E Varjonen*, N Kalkkinen$, T Reunala* *Department of Dermatology, University of Helsinki and Hospital for Skin and Allergic Diseases tFinnish Institute of Occupational Health Slnstitute of Biotechnology, University of Helsinki Wheat-dependent, exercise-induced anaphylaxis (WDEIA) is a severe form of allergy for which ingestion of wheat before physical exercise induces symptoms of anaphylaxis. Bread, pizza, pasta, etc., and exercise, such as walking, jogging, and dancing are the most prominent triggers of WDEIA. We recently identified 18 adult patients with WDEIA and showed that the major IgE-binding allergen in wheat is a novel y-like gliadin. It seems that cereals other than wheat can also trigger symptoms in WDEIA and, hence, treatment with a gluten-free diet, i.e., a diet excluding wheat, rye, and barley, has been recommended. The aim of this study was to examine whether rye and barley contain allergens cross-reacting with wheat y-like gliadin. Sera were obtained from 23 adult patients with WDEIA. Immunoblotting with pooled patient sera and with serum from a rabbit immunized with wheat y-like gliadin were used to identify the IgE-binding proteins in rye and barley. Cross-reactivity was assessed by immunoblot inhibition. The cross-reactive allergens were purified by gel filtration and reversed-phase chromatography and submitted to N-terminal amino acid sequencing. Cross-reactivity was further studied by ELISA and ELISA inhibition and in vivo reactivity by skin prick testing. In immunoblotting, 65 and 32 kD proteins in rye, and a 34 kD protein in barley bound antibodies from the patient and rabbit sera. The amino acid sequence of the 65 kD rye protein showed 100% identity to rye y-70 secalin and the 32 kD protein was almost identical to y-35 secalin. The barley 34 kD protein had 100% sequence identity to y-hordein 3. In ELISA, 21 (91%) patients showed IgE antibodies to y-70 secalin, 19 (83%) to y-35 secalin and 21 (91%) to y-hordein 3. Skin prick testing was performed in 15 patients and was positive with y-70 secalin in IO (67%), with y-35 secalin in 3 (20%) and with y-hordein 3 in 7(47%) patients. In ELISA inhibition, y-like gliadin inhibited over 90% of the IgE binding to ysecalins and y-hordein on solid-phase. When y-secalins and yhordein were used as inhibitors and y-like gliadin on solid-phase, the inhibition was about 50%. These results show that y-secalins in rye and y-hordein in barley are important, IgE-binding allergens cross-reacting with wheat ylike gliadin in WDEIA. Due to this cross-reactivity, treatment with a gluten-free diet, i.e., a diet excluding wheat, rye, and barley, is indicated for all patients with WDEIA.
Abstracts
J ALLERGY CLIN IMMUNOL JANUARY
549
550
Allergic
Reactions
Wegrzyn*.
Heidi
School Anna Nowok*John Hopkins University School of Medicine, Eudowood Division of Pediatric Allergy and Immunology, Baltimore, MD tuniversity of Maryland Medical Systems, Department of Pediatrics, Baltimore, MD Accidental ingestions are common in children with food allergies. We phone-surveyed parents of 50 patients (median age 6.9, range: 3.2-19.3 years) with food allergies seen in our clinic from April to August 1999 in order to better characterize their reactions to foods at school. 8 children were home schooled, 7 due to food allergy. Of the remaining 42 children, 67% attended school. 33% preschool. 48% were allergic lo four or more, 29% to three, 14% lo one, and 9% to two foods. 24 (57%) children had 65 accidental ingestions in the past 2 years. including I6 reactions in 9 children that occurred at school (63% elementary, 33% preschool). Parents were unable lo identify the food in 7 reactions, peanut and milk were implicated in 3 reactions each, egg in 2, and celery in I reaction. 5 reactions occurred in classrooms with eating areas, 4 in regular classrooms, 2 both in the cafateria and playground. The location could not be identified in 3 reactions. Symptoms included: hives-8, wheezing-4, pruritus-3, vomiting/diarrhea-3, facial angioedema-2, and contact skin rash- I reaction. Treatment included: oral antihistamines-12, epinephrine and bronchodilalors in 2 each, and treatment was not specified in I reaction. I1 reactions were treated by a nurse. 2 by a teacher, 1 by EMTs, I by mother, and in I the person was not identified. 8 I % of reactions were treated within IO minutes. Paren& provided schools with protocols and medications for treatment of acute allergic reactions in 91% and 93% of children respectively. The medications were kept in the nurse’s office in 46%. with the teacher in 23%. in child’s bag in l8%, and in the front office in 15%. 69% of parents provided all meals for their children, 3 I % allowed selected foods. 4 I % of children ate their meals in the classroom, 38% in school cafeteria, 5% at a restricted table, 2% in the nurse’s office, and 2% did not eat at school at all. We contacted 24 of the schools which the children attended (54% private. 46% public). There were median 5 children with food allergies per school (range l-25). 5 allergic reactions to foods in the past two years were reported in 4 schools (3 elementary, one preschool). 50% of schools utilized their routine medication forms for instructions for treatment of allergic reactions, whereas 50% used specific forms. 7 I % of schools reported special accommmodations for children with food allergies: restricted peanuts from the classroom-25%. alternative meals-21 %, separate eating areas- 175, peanut-free tables in the cafeteria-l%, other- 17%. CONCLUSIONS: 38% of children who had had accidental ingestions in the past 2 years experienced at least one acute reaction to food at school. Reactions at schools accounted for 25% of all reactions encountered within past 2 years. Although each of the reactions was successfully treated, there was no protocol or medications available for 9% and 7% of all children respectively. Peanut
Allergic
to
Isenbergf,
Foods
Robert
parental surrogates described 124 school reactions to peanut (I 15) or tree nuts (9). Physicians had verified the food allergy for 99% of the subjects and 85% had specific IgE tests performed, all were positive. Sixty-four percent of the reactions occurred in daycare or preschool, the remainder in elementary school or higher. Among those in elementary school, 68% were public schools. In 25% of the cases, the school reaction was their first indication of peanut allergy. Reactions resulted from ingestion (60%). skin contact (24%) and inhalation (15%). However, in the majority of reactions due to inhalation, concomitant ingestion/skin contact could not be ruledout. Peanut butter craft projects were commonly responsible for the skin contact (60%) or inhalation (44%) reactions. Reactions often occurred during parties/special occasions (24%). In 24 instances, the reaction symptoms were not noted until the parent observed the child. usually at the end of the school day. Symptoms were severe in 24% of reactions. For 90% of the reactions, medications were given (86% received antihistamines. 33% epinephrine). For 57% of those treated, parents administered the medication either after being summoned to the school (63%) or because they were the first to notice a reaction. Overall, 53% of the medications were given in the school building, including epinephrine in I9 cases. Teachers gave epinephrine in 4 cases, nurses in 6, and parents or other personnel in the remainder. Among patients with previously identified allergy requiring. but not receiving, medicine in school (36 cases), a variety of reasons were given including, reaction not initially noticed, parents called to pick child up, and unable to activate epinephrine. Among school personnel, the teachers were most likely lo take control of Ihe incidents (77% had no school nurse present). An emergency plan was in place for 33% of the reactions but was followed correctly 73% of the time. Three reactions occurred despite a peanut “ban”. A number of responses were taken after the reaction including home meal preparation, educational efforts directed to staff and students, allergy free tables and classroom peanut bans. In conclusion, school peanut-allergic reactions can be severe and frequently require medical treatment; school personnel must be educated to recognize the signs of a reaction, to treat symptoms promptly and appropriately and to avoid accidental exposures, including exposure from peanut butter craft projects
in the
A. Wood*
Reactions in Schools TJ Furlong*. J DeSimone*, *Food Allergy Network, Fairfax VA tMount Sinai School of Medicine, New York, NY It is not uncommon for food allergic reactions to occur in schools, but the clinical features of these reactions have not been well described. Using a standard questionnaire, we conducted 100 telephone interviews of parental surrogates from among a random sampling of registrants in the National Peanut and Tree Nut Allergy Registry who indicated allergic reaction(s) in school. The 100
SH Sichererf
2000
551
Pattern of Food Hypersensitivity Challenges in Children with Chatcharee,
HA
Sampson,
Over a Decade of Oral Food Atopic Dermatitis LK El/man, P SH Sicherer Mount Sinai School of
Medicine, New York, NY There is a clinical impression that food allergy has become more prevalent in terms of the number of foods to which allergies occur and sensitization rates. However, formal studies regarding patterns of food allergy over time are lacking. Through chart review, we compared children with atopic dermatitis referred lo our clinical research center for evaluation of food hypersensitivity by oral food challenges a decade ago (Group “A”- 5/88 to 6/89) to those evaluated in the past year (Group “B”- 5/98 to 6/99). There were 43 children in group A (mean age 7.8 years, 47% with asthma) and 32 in group B (mean age 8.2 years, 62% with asthma). A total of 138 oral food challenges were performed in Group A and 78 in group B. “Major” food allergens have typically been considered cow’s milk, egg. wheat, soy, peanut, nuts, fish and shellfish. These major food allergens accounted for 7 I % of the challenges performed in group A, but only 58% of the challenges in group B (chi-square p < 0.001). The reduction in challenges to these major food allergens was influenced by decisions not lo challenge based upon food-spe-
Abstracts
J ALLERGY CLIN IMMUNOL VOLUME 105, NUMBER 1. PART 2
citic IgE (F-IgE; Pharmacia CAP-RAST FEIA) antibody levels indicating a high risk (995%) for reactions [Sampson & Ho JACI 1997;100:444] primarily among those eliminating, but not challenged to egg and milk. The overall proportion of positive challenges to major food allergens was 40% in each group and was significantly higher (Chi square p = 0.007) than the proportion of positive challenges to “minor” foods (group A- 15%. group B- 12%). Considering both groups, the minor food allergens that elicited positive oral challenges (positive/total tested) included barley-112, corn-l/9, beef- 4/10, pork-115 tomato-2/6, and mustard-l/l. ChaIlenges were negative to 21 other foods. The proportion of positive challenges caused by the major allergens was not significantly different (p=O.6) between group A (87%) and group B (82%; or 91% with inclusion of positive predictive F-IgE to egg, milk). More detailed analysis was performed for egg, cow’s milk and soy since 07 challenges were performed in each group. Among those eliminating these foods, the proportion with a positive challenge or a high F-IgE was greater between group A and B only for cow’s milk (34% to 70%, respectively, p = 0.006). Sensitization (wheal > 3 mm mean diameter, F-IgE > 0.7 kU/L) to milk, egg, wheat, soy and peanut were not significantly different between groups (overall sensitization 74% in group A and 79% in group B). In conclusion, these data suggest the following: that allergy to “minor” foods has not increased, that most clinical reactivity 080%) is accounted for by a few “major” food allergens, that clinical reactions to cow’s milk have increased, and that sensitization rates remained stable in these referral populations over the past decade. 552
A Neonatal Pig Model for Peanut Allergy RM Helm, G Cockrell, C Connaughton, GA Bannon. AW Buds Our in vitro results over the last ten years have identified several peanut proteins, Ara h 1.2, and 3 that are the major allergens contributing to the hypersensitivity responses in humans. Based on these studies, we proposed to develop an animal model that will further enable us to investigate the IgE-mediated gastrointestinal allergic response to foods. The similarities in digestive function in the neonatal pig and man make this an attractive model to improve our knowledge of gastrointestinal hypersensitivity to peanuts. Pregnant sows at day 109 of gestation were fed an NRC-approved sow lactation diet consisting of a soybean/peanut-free diet throughout lactation. Newborn piglets were allowed to suckle ad libitum for three weeks and then weaned to nursery diets lacking soybean/peanut proteins meeting NRC regulations at three, seven, and thirteen weeks, respectively. Three-day old piglets were divided into three groups and either intragastrically (i.g.) or intraperitoneally (i.p.) sensitized with crude peanut meal as follows: Group 1: 2 grams peanut meal in phosphate buffered saline (PBS) i.g. on day 3,4, and 5 with lOOpI cholera toxin (Ctx): Group 2: 2 grams of peanut meal in PBS i.g. on day 9, IO. and I I with lOOpI Ctx; and Group 3: 5OOpg peanut meal in PBS on day 3, 4. and 5 i.p. with lOOpI Ctx. Each group was subsequently boosted I week later with the respective peanut sensitization protocol. Three weeks following sensitization, intragastric challenge with 10 grams of peanut meal in PBS resulted in symptoms ranging from erythematous rashes, cyanosis about the snout and ears, lethargy, vomiting, and respiratory distress in 25% of the piglets sensitized to peanut meal. Control animals challenged with IO grams of peanut meal did not respond with any
SlB3
of the symptoms associated with peanut-sensitized animals. Skin test results with peanut extract one week later showed wheal and erythema skin test reactions typical of immediate type allergen skin tests in sensitized piglets with no response in control animals. In conclusion, we have preliminary evidence that we can successfully mimick the gastrointestinal food allergy response in neonatally peanut-sensitized piglets. Dosage and sensitization/challenge protocols are under further investigation to increase our success rate for the pig model of gastrointestinal hypersensitivity. 553
Rye y-Secalin and Barley y-HordeIn Are Cross-reactive Allergens in Wheat-dependent, Exercise-induced Anaphylaxis K Palosuo*f, H Aleniusf. E Varjonen*, N Kalkkinen$, T Reunala* *Department of Dermatology, University of Helsinki and Hospital for Skin and Allergic Diseases tFinnish Institute of Occupational Health Slnstitute of Biotechnology, University of Helsinki Wheat-dependent, exercise-induced anaphylaxis (WDEIA) is a severe form of allergy for which ingestion of wheat before physical exercise induces symptoms of anaphylaxis. Bread, pizza, pasta, etc., and exercise, such as walking, jogging, and dancing are the most prominent triggers of WDEIA. We recently identified 18 adult patients with WDEIA and showed that the major IgE-binding allergen in wheat is a novel y-like gliadin. It seems that cereals other than wheat can also trigger symptoms in WDEIA and, hence, treatment with a gluten-free diet, i.e., a diet excluding wheat, rye, and barley, has been recommended. The aim of this study was to examine whether rye and barley contain allergens cross-reacting with wheat y-like gliadin. Sera were obtained from 23 adult patients with WDEIA. Immunoblotting with pooled patient sera and with serum from a rabbit immunized with wheat y-like gliadin were used to identify the IgE-binding proteins in rye and barley. Cross-reactivity was assessed by immunoblot inhibition. The cross-reactive allergens were purified by gel filtration and reversed-phase chromatography and submitted to N-terminal amino acid sequencing. Cross-reactivity was further studied by ELISA and ELISA inhibition and in vivo reactivity by skin prick testing. In immunoblotting, 65 and 32 kD proteins in rye, and a 34 kD protein in barley bound antibodies from the patient and rabbit sera. The amino acid sequence of the 65 kD rye protein showed 100% identity to rye y-70 secalin and the 32 kD protein was almost identical to y-35 secalin. The barley 34 kD protein had 100% sequence identity to y-hordein 3. In ELISA, 21 (91%) patients showed IgE antibodies to y-70 secalin, 19 (83%) to y-35 secalin and 21 (91%) to y-hordein 3. Skin prick testing was performed in 15 patients and was positive with y-70 secalin in IO (67%), with y-35 secalin in 3 (20%) and with y-hordein 3 in 7(47%) patients. In ELISA inhibition, y-like gliadin inhibited over 90% of the IgE binding to ysecalins and y-hordein on solid-phase. When y-secalins and yhordein were used as inhibitors and y-like gliadin on solid-phase, the inhibition was about 50%. These results show that y-secalins in rye and y-hordein in barley are important, IgE-binding allergens cross-reacting with wheat ylike gliadin in WDEIA. Due to this cross-reactivity, treatment with a gluten-free diet, i.e., a diet excluding wheat, rye, and barley, is indicated for all patients with WDEIA.