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Medline ® Abstracts for References 31,32

of 'Oral food challenges for diagnosis and management of food allergies'

The natural history of peanut allergy.
Skolnick HS, Conover-Walker MK, Koerner CB, Sampson HA, Burks W, Wood RA
J Allergy Clin Immunol. 2001;107(2):367.
BACKGROUND: It has traditionally been assumed that peanut allergy is rarely outgrown.
OBJECTIVE: The goal of this study was to determine the number of children with peanut allergy who become tolerant of peanut.
METHODS: Patients aged 4 to 20 years with a diagnosis of peanut allergy were evaluated by questionnaire, skin testing, and a quantitative antibody fluorescent-enzyme immunoassay. Patients who had been reaction free in the past year and had a peanut IgE (PN-IgE) level less than 20 kilounits of antibody per liter (kU(A)/L) were offered an open or double-blind, placebo-controlled peanut challenge.
RESULTS: A total of 223 patients were evaluated, and of those, 85 (PN-IgE<0.35-20.4 kU(A)/L [median 1.42 kU(A)/L]) participated in an oral peanut challenge. Forty-eight (21.5%) patients had negative challenge results and were believed to have outgrown their peanut allergy (aged 4-17.5 years [median 6 years]; PN-IgE<0.35-20.4 kU(A)/L [median 0.69 kU(A)/L]). Thirty-seven failed the challenge (aged 4-13 years [median 6.5 years]; RAST<0.35-18.2 kU(A)/L [median 2.06 kU(A)/L]). Forty-one patients with PN-IgE levels less than 20 kU(A)/L declined to undergo challenge, and 97 were not eligible for challenge because their PN-IgE levels were greater than 20 kU(A)/L or they had had a recent reaction. Sixty-seven percent of patients with PN-IgE levels less than 2 kU(A)/L and 61% with levels less than 5 kU(A)/L had negative challenge results. Of those who underwent challenge, PN-IgE levels for those who passed versus those who failed were different at the time of challenge (P = .009), but not at the time of diagnosis (P = .25).
CONCLUSION: This study demonstrates that peanut allergy is outgrown in about 21.5% of patients. Patients with low PN-IgE levels should be offered a peanut challenge in a medical setting to demonstrate whether they can now tolerate peanuts.
Department of Pediatrics, Johns Hopkins University, Baltimore, Md, USA.
Fatty acid deficiency profile in children with food allergy managed with elimination diets.
Aldámiz-Echevarría L, Bilbao A, Andrade F, Elorz J, Prieto JA, Rodríguez-Soriano J
Acta Paediatr. 2008;97(11):1572.
AIM: To evaluate plasma fatty acid (FA) composition of children with food allergy undergoing elimination diets that avoided the offending antigens.
METHODS: Twenty-five children (14 male, 11 female) aged 3.8 +/- 1.6 years (range 2-7 years) affected of multiple food allergy and managed with elimination diets participated in a cross-sectional study. Results of plasma fatty acids were compared with data obtained in 61 healthy children.
RESULTS: The patients had significantly lower values for plasma content in total polyunsaturated fatty acids, omega3 polyunsaturated fatty acids and long-chain omega3 polyunsaturated fatty acids (p<0.001) and particularly, in eicosapentaenoic acid (EPA) (20:5omega3) and docosahexaenoic acid (DHA) (22:6omega3) (p<0.001). Moreover, all established indices (essential fatty acid [EFA]index ((omega3 +omega6)/(omega7 +omega9)) (p<0.001) and sufficiency of docosahexaenoic acid index (C22:6omega3/C22:5omega6) (p<0.001)) confirmed the presence of EFA deficiency.
CONCLUSION: Children with food allergy managed with restricted intake of foods such as milk, egg, fish and vegetables are at risk of developing a deficiency in EFA and particularly in omega3 long-chain polyunsaturated fatty acids, which are especially necessary for adequate growth, neurological development and cardiovascular health.
Divisions of Metabolism, Department of Pediatrics, Hospital de Cruces, Basque University School of Medicine, Bilbao, País Vasco, Spain. luisjose.aldamiz-echevarazuara@osakidetza.net