Royal Prince Alfred Hospital Royal Prince Alfred Hospital
Allergy Unit

Student research


Demographic and Clinical Characteristics of Food-Induced Anaphylaxis in Atopic Children, Aged 0-5 Years: A Case-Control Study

by
Rachel Myhill
Bachelor of Nutrition and Dietetics, University of Wollongong
Supervisors: Katherine Jukic, Velencia Soutter, Robert Loblay, Anne Swain
October 2007

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Abstract

Introduction: The incidence of food allergy and occurrence of food-induced anaphylaxis is increasing. Understanding the epidemiology of anaphylaxis has been challenged by inconsistencies in definition, and lack of a universal grading system. This study defined anaphylaxis as ‘a severe, life threatening allergic reaction, characterised by signs of cutaneous, gastrointestinal, respiratory and cardiovascular compromise’. To date, literature concerning anaphylaxis has primarily researched clinical symptoms, risk factors (typically asthma) and management associated with the reaction. The primary aims of this study was to analyse demographic and clinical characteristics of atopic children who have had an anaphylaxis.

Methods: This retrospective case-control study was carried out at the RPA Allergy Unit in Sydney. Children were recruited if they were atopic and aged 0-5 years on presentation at the Allergy Unit. The patient database and files of 672 subjects were reviewed, and cases (n=218) were identified, i.e. if the child had a history of anaphylaxis according to our definition. Characteristics of children who had an anaphylaxis (graded as mild, moderate or severe) were pre-determined and analysed. Such characteristics included: symptoms of the reaction; age and sex of the child; presence or history of asthma; the type, form and SPT of the causative allergen; and administration of adrenaline.

Results: Characteristics: The majority of cases had a mild or moderate anaphylactic reaction (85%), and were aged between 1 and 3 years. Skin symptoms occurred in 90% of all reactions. The main food allergens that caused anaphylaxis were peanut (42%), egg (21%) and milk (17%), and their corresponding SPT size most commonly ranged between 6 mm and 8 mm. The allergen was consumed as a whole food in approximately two-thirds of cases, rather than as an ingredient or component of a food.

Conclusion: Establishment of a universal grading system would enable improved clinical observation and management of anaphylaxis, and better comparison of the results of this study with other studies.