Oral Immunotherapy for Egg Allergy in Children Aged 6 to 16

The prevalence of egg allergy among children varies from 0.5% to 3% and is thus the second most common food allergy in children. Until recently, the only treatment for egg allergy was in many cases a life-long avoidance of egg protein. Due to the large number of egg-allergic children, oral immunotherapy (OIT) to egg has been suggested to be of probable benefit to cure children with egg-allergy. Several studies have been conducted to evaluate the safety and clinical outcome of egg OIT. However, concerning efficacy and safety of egg OIT more data, and alternative procedures are required to gain a safe, simple and inexpensive immunotherapy protocol . Previous egg OIT studies have mainly used egg white in the immunotherapy, rather than more natural and inexpensive whole egg products.

The aim of this study is to determine the efficacy of a 12-month egg oral immunotherapy (OIT) protocol with a cooked whole egg product including yolk and egg white. Furthermore, the effects of whole egg OIT on humoral immune responses are investigated.

The investigators hypothesize that oral administration of a whole egg product with incremental dosing will increase the individual threshold for allergic reactivity to egg protein and may result in full tolerance without any reaction to egg.

Other study aims include investigating the differences in efficacy and side effects of whole-egg OIT in children with asthma and without asthma. In this study it is hypothesized that children with asthma have more symptoms than non-asthmatic children during the treatment. Furthemore, the level of asthma control during OIT is investigated.

The study is a prospective multicenter randomized open trial, investigating the efficacy, safety and immunological mechanisms of oral egg immunotherapy in children (aged 6 to 16). Children with egg allergy, egg avoidance diet, immediate reaction in a food challenge test for egg within the last six months and elevated serum egg-specific immunoglobulin E (IgE) levels, are recruited into the study. Children with uncontrolled asthma, severe cardiovascular disease and autoimmune disease or families with poor compliance are excluded from the study.

Study participants are divided into two groups: patients with asthma and without asthma. Both groups are separately randomized into immunotherapy or follow-up without the treatment. The immunotherapy and follow-up last 12 months in total. After 12 months of enrolment, participants in the follow-up group are entitled to take actively part in the egg OIT protocol.

In immunotherapy groups (asthma or no-asthma), meatball, bun or bread roll, including well-cooked whole-egg is given daily to the patients, starting from a minimal dosage (1/200 of the protein content of whole egg) and increasing the dosing every 1-2 weeks until a dosage of 1/5 of the protein content of a whole egg is reached. The initial dosage is given at the hospital outpatient clinic. The patients and their parents will be prepared for emergency treatment of severe allergic reactions and are given instructions to carry adequate medication with them. Patients in the intervention groups take levocetrizine 5 mg or cetirizine 10 mg daily until three months of maintenance dosage.

Blood samples, skin prick tests, lung function tests and exhaled nitric oxide levels are taken from all study participants. All the above-mentioned tests are taken before the therapy and at the time points of 6 and 12 months.

Inclusion criteria

• Age 6 to 16 years
• Elevated spesific serum IgE to egg (> 5 kU/l) and/or positive skin prick to egg allergen
• Positive oral food challenge for egg or anaphylaxis reaction to egg within the 6 months
• Diet free from egg in any form

Exclusion criteria

• Age less than 6 years or more than 16 years
• Poor asthma control or uncontrolled asthma
• Severe/significant cardiovascular disease
• Autoimmune disease
• Malignancy
• Medication: beta bloker, angiotensin-converting-enzyme inhibitors (ACE inhibitors), Monoamine oxidase inhibitors (MAOIs)
• Poor compliance
• Fear of immunotherapy
• Desensitization to alfa-gal-protein (mammalian meat allergy)