Specific oral tolerance induction in paediatric patients with persistent egg allergy

Desensitisation or specific oral tolerance induction (SOTI) to food is a new topical-therapeutic approach of food allergy for those children who have not achieved tolerance spontaneously. The objective of this study is to induce clinical tolerance in children with persistent allergy using an oral desensitisation protocol with powdered pasteurised egg.

Seventy-two patients with egg allergy confirmed by open oral challenge test were randomly assigned to SOTI or elimination diet as a control group. Forty children (5-15 years) underwent a SOTI beginning with 1mg and increasing the dosage weekly until a dose of 10g, equivalent to an egg. The control group included 32 patients (4-15 years).

The procedure's average duration was 10 weeks (range 4-28 weeks). Three patients were withdrawn from the protocol for persistent gastrointestinal symptoms. During SOTI, 21 children (52.5%) presented symptoms. In eight the symptoms were mild and required no treatment. In the other 13 (61.90%), the reactions were more severe. Seventeen children finished the treatment over a year ago and 20 in the past 6-12 months. Thirty-seven patients (92.5%) in the active group achieved tolerance to egg, versus 21.8% in the control group. We only found statistically significant differences (p<0.05) for skin prick tests with powdered egg at various dilutions and IgG levels with egg white after SOTI. Specific IgE concentration did not change significantly.

Our SOTI protocol is a safe, effective treatment for food allergy and of reasonable duration, confirming that tolerance can be induced in children who have not achieved it spontaneously.