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296 Double blind food challenges (FC) in a prospective allergy prevention program for high risk infants
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lHEIEVEXOP~pTOF!IHEANTIl8ODYHF,SFCH~ToFoo AND INHALANTALIXIN INFANTS ANDYOING CHILDHEN. s. Rmtree, *J.J. Cogswell, T.A.E. Platts-Mills, E.B. Mitchell. Clinical Research Centre. Harrcnv. LIK and *Poole Hosnital. Corset UK In a prospective study of 97 child&n, we have assessed the developrnznt of the specific ab responses to purified food and inhalant allergens over the 1st 5 years of life. Using RPST, egg specific IgE ab occurred in m of the children with the mean peak level at 12 mths. By the 2nd year the prevalence of this ab increased while the mean level decreased. Milk specific I@ ab could not be demnstrated in any subject, including those 4 with positive skin tests. Using antigen binding HIA food specific I& ab w~demonstrable at 3 mths in the majority of children. These responses had peaked and begun to fall by the 5th year. In contrast few children had detectable I@ or IgG ab to inhalant allergens before the 1st 2 years of life. However, both the levels and prevalence of specific ah increased from the 2nd to the 5th year and was greater in skin test positive individuals. Envimnmental influences were studied: (1) breast feeding was shown not to protect against disease development despite differences in IgG ab levels to milk and (2) a hi& level of dust mite expcsure was associated with an increased prevalence of pc&tive skin prick tests to dust mite and hi@ ab levels. This study indicates differences in the hunoral responses to fcod and inhalant allergens. Environmental factors appear to influence the dsvelopmznt of these responses.
ADVERSE REACTIONS TO FOODS DURING THE FIRST THREE YtARS OF LIFE. S. Allan Bock, M.D., Denver. Colorodo Of 501 consecutively born children, 480(96%) completed a prospective survey of adverse reactions to food from birth to 3 yrs. Evaluation of the reactions allowed classification as confirmed, probable, possible, unlikely, or not reproduced. Skin tests were performed in some subjects. Of the 501 children, 192(38%) hod 216 symptoms related to diet; 165(76%) of 216 total reactions were suspected between O-12 months of age; 79(37%) of the 216 suspected reactions were to fruit; 39(8%) of 501 children had 41 confirmed or probable reactions excluding fruit; 72(14%) of the 501 children had symptoms ottributed to milk. There were 36(5%) of children with confirmed or probable reactions to milk. The durotion of the problem wos brief. Mean time to reintroduction of foods was: confirmed I4 mos, probable I2 mos, possible 9 mos, unlikely 8 mos, and not reproduced 2 mos. Foods confirmed or probable were milk, soy, peanut, egg, wheat, corn, chocolate, rice, coconut, tomato, orange, apple, and grape. Symptoms confirmed included GI, skin, respiratory. Behavioral reactions occurred only in conjunction with another symptom. 43 children from all categories had skin tests. There were 4 positive puncture tests ond 3 positive introdermol tests. The following conclusions have been reached: I) Symptoms due to foods are o common complaint and occur most often during the first year of life and decline in the following 2 years; 2) Foods under suspicion should be rechallenged promptly and systemoticolly since many complaints will not be reproduced; 3) Fruits cause a large number of reactions, the mechanism for which is uncleor; 4) Skin tests should not be undertaken until the reaction has been confirmed.
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IGE MEDIATED, RAST-POSITIVE ALLERGY TO PEANUT (PN), COW'S MILK (M) AND EGG (E): RELATIONSHIP TO FEEDING AND MATERNALDIET. J.W. Gerrard, D.M., L. Perelmutter, Ph.D., Saskatoon and Ottawa, Canada The purpose of this study was to identify factors influencing the development of IgEmediated allergies to PN, M and E. Nineteen children aged 1 to 10 years (average 3 years 5 months) were studied. Ten were sensitive to PN only, 7 to PN, M and E, 1 to PN and M, and 1 to M and E. Reactions included anaphylaxis, asthma, urticaria, eczema, vomiting and rhinorrhea. Reactions in all but 1 occurred on first exposure to the food, suggesting that sensitization had occurred either antenatally or via breast milk. All children sensitized to M and E, and 16 of 18 children sensitized to PN had been breast fed, mean duration of breast feeding was 11 months. Most mothers had generous quantities of the food to which their babies were sensitized, but 2 mothers whose babies developed PN allergy, and 1 mother whose baby developed E allergy, did not have these foods antenatally or when breast feeding their babies. Breast feeding by itself does not prevent the development of food allergies in the baby. Because allergies' to PN, M and E occur on first exposure, sensitization probably occurred either antenatally or via the breast. Eliminating these foods from the mother's diet would be expected to prevent development of the corresponding allergy, but our data suggest that this cannot be guaranteed.
DOUBLEBLIND FOODCHALLENGES(FC) IN A PROSPECTIVEALLERGYPREVENTIONPROGRAMFOR HIGH RISK INFANTS. M. Mellon. M.D.. S. Heller. R.N., 0' M.D.. R. wer. M.D. and R. Zeiner. M.D.. Ph.&, San Diego, California As part of a prospective allergy prevention study, 29 infants, born to allergic parents (21 bilateral), who exhibited a non-anaphylactic but positive historical reaction to food (HRF) and/or positive food specific IgE (FSIgE) by skin test or RAST, underwent 32 FC at ages 5 to 45 months (x=22 months). Antigens for skin testing and opaque capsules were supplied by the NIAID under a specific IND. From 0.26 to 8.4 grams of food including egg (8), milk (6), peanut (2), wheat (l), and corn (1) elicited within 5-300 minutes 18 positive FC in 15 infants. Reactions were cutaneous (17/18), nasal and/or pulmonary (8/18) and gastrointestinal (3/18). Positive FC occurred in 13/14 (93%) infants with both positive HRF and FSIgE compared to l/11 (9%) with positive HRF but negative FSIgE. Each of 4 solely breast fed infants with positive FSIgE had positive FC while 3/3 infants with positive FSIgE but negative HRF had negative FC had elevated serum FC. Infants with positive IgE (p=.O2), positive FSIgE (p-.003) and existing atopic disease (p=.Ol) more often than infants with negative FC. Of the positive FC, 12118 resolved spontaneously, 3/18 required po antihistamine or nebulized metaproterenol, and 3/18 were potentially severe, requiring adrenalin. In conclusion, adverse food reactions in prospectively followed infants of allergic parents are typically IgE mediated and can be confirmed by double blind FC.
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lHEIEVEXOP~pTOF!IHEANTIl8ODYHF,SFCH~ToFoo AND INHALANTALIXIN INFANTS ANDYOING CHILDHEN. s. Rmtree, *J.J. Cogswell, T.A.E. Platts-Mills, E.B. Mitchell. Clinical Research Centre. Harrcnv. LIK and *Poole Hosnital. Corset UK In a prospective study of 97 child&n, we have assessed the developrnznt of the specific ab responses to purified food and inhalant allergens over the 1st 5 years of life. Using RPST, egg specific IgE ab occurred in m of the children with the mean peak level at 12 mths. By the 2nd year the prevalence of this ab increased while the mean level decreased. Milk specific I@ ab could not be demnstrated in any subject, including those 4 with positive skin tests. Using antigen binding HIA food specific I& ab w~demonstrable at 3 mths in the majority of children. These responses had peaked and begun to fall by the 5th year. In contrast few children had detectable I@ or IgG ab to inhalant allergens before the 1st 2 years of life. However, both the levels and prevalence of specific ah increased from the 2nd to the 5th year and was greater in skin test positive individuals. Envimnmental influences were studied: (1) breast feeding was shown not to protect against disease development despite differences in IgG ab levels to milk and (2) a hi& level of dust mite expcsure was associated with an increased prevalence of pc&tive skin prick tests to dust mite and hi@ ab levels. This study indicates differences in the hunoral responses to fcod and inhalant allergens. Environmental factors appear to influence the dsvelopmznt of these responses.
ADVERSE REACTIONS TO FOODS DURING THE FIRST THREE YtARS OF LIFE. S. Allan Bock, M.D., Denver. Colorodo Of 501 consecutively born children, 480(96%) completed a prospective survey of adverse reactions to food from birth to 3 yrs. Evaluation of the reactions allowed classification as confirmed, probable, possible, unlikely, or not reproduced. Skin tests were performed in some subjects. Of the 501 children, 192(38%) hod 216 symptoms related to diet; 165(76%) of 216 total reactions were suspected between O-12 months of age; 79(37%) of the 216 suspected reactions were to fruit; 39(8%) of 501 children had 41 confirmed or probable reactions excluding fruit; 72(14%) of the 501 children had symptoms ottributed to milk. There were 36(5%) of children with confirmed or probable reactions to milk. The durotion of the problem wos brief. Mean time to reintroduction of foods was: confirmed I4 mos, probable I2 mos, possible 9 mos, unlikely 8 mos, and not reproduced 2 mos. Foods confirmed or probable were milk, soy, peanut, egg, wheat, corn, chocolate, rice, coconut, tomato, orange, apple, and grape. Symptoms confirmed included GI, skin, respiratory. Behavioral reactions occurred only in conjunction with another symptom. 43 children from all categories had skin tests. There were 4 positive puncture tests ond 3 positive introdermol tests. The following conclusions have been reached: I) Symptoms due to foods are o common complaint and occur most often during the first year of life and decline in the following 2 years; 2) Foods under suspicion should be rechallenged promptly and systemoticolly since many complaints will not be reproduced; 3) Fruits cause a large number of reactions, the mechanism for which is uncleor; 4) Skin tests should not be undertaken until the reaction has been confirmed.
295
298
178
IGE MEDIATED, RAST-POSITIVE ALLERGY TO PEANUT (PN), COW'S MILK (M) AND EGG (E): RELATIONSHIP TO FEEDING AND MATERNALDIET. J.W. Gerrard, D.M., L. Perelmutter, Ph.D., Saskatoon and Ottawa, Canada The purpose of this study was to identify factors influencing the development of IgEmediated allergies to PN, M and E. Nineteen children aged 1 to 10 years (average 3 years 5 months) were studied. Ten were sensitive to PN only, 7 to PN, M and E, 1 to PN and M, and 1 to M and E. Reactions included anaphylaxis, asthma, urticaria, eczema, vomiting and rhinorrhea. Reactions in all but 1 occurred on first exposure to the food, suggesting that sensitization had occurred either antenatally or via breast milk. All children sensitized to M and E, and 16 of 18 children sensitized to PN had been breast fed, mean duration of breast feeding was 11 months. Most mothers had generous quantities of the food to which their babies were sensitized, but 2 mothers whose babies developed PN allergy, and 1 mother whose baby developed E allergy, did not have these foods antenatally or when breast feeding their babies. Breast feeding by itself does not prevent the development of food allergies in the baby. Because allergies' to PN, M and E occur on first exposure, sensitization probably occurred either antenatally or via the breast. Eliminating these foods from the mother's diet would be expected to prevent development of the corresponding allergy, but our data suggest that this cannot be guaranteed.
DOUBLEBLIND FOODCHALLENGES(FC) IN A PROSPECTIVEALLERGYPREVENTIONPROGRAMFOR HIGH RISK INFANTS. M. Mellon. M.D.. S. Heller. R.N., 0' M.D.. R. wer. M.D. and R. Zeiner. M.D.. Ph.&, San Diego, California As part of a prospective allergy prevention study, 29 infants, born to allergic parents (21 bilateral), who exhibited a non-anaphylactic but positive historical reaction to food (HRF) and/or positive food specific IgE (FSIgE) by skin test or RAST, underwent 32 FC at ages 5 to 45 months (x=22 months). Antigens for skin testing and opaque capsules were supplied by the NIAID under a specific IND. From 0.26 to 8.4 grams of food including egg (8), milk (6), peanut (2), wheat (l), and corn (1) elicited within 5-300 minutes 18 positive FC in 15 infants. Reactions were cutaneous (17/18), nasal and/or pulmonary (8/18) and gastrointestinal (3/18). Positive FC occurred in 13/14 (93%) infants with both positive HRF and FSIgE compared to l/11 (9%) with positive HRF but negative FSIgE. Each of 4 solely breast fed infants with positive FSIgE had positive FC while 3/3 infants with positive FSIgE but negative HRF had negative FC had elevated serum FC. Infants with positive IgE (p=.O2), positive FSIgE (p-.003) and existing atopic disease (p=.Ol) more often than infants with negative FC. Of the positive FC, 12118 resolved spontaneously, 3/18 required po antihistamine or nebulized metaproterenol, and 3/18 were potentially severe, requiring adrenalin. In conclusion, adverse food reactions in prospectively followed infants of allergic parents are typically IgE mediated and can be confirmed by double blind FC.