Egg white-specific IgE level as a tolerance marker in the follow up of egg allergy.

Forty patients with symptomatic immediate hypersensitvity to egg who did not have atopic dermatitis were evaluated to determine if they continued to remain clinically symptomatic. Each had specific IgE in vitro and positive prick-test to egg. All patients were on an egg elimination diet. During the follow-up an open egg rechallenge was performed along with a determination of egg white-specific IgE by CAP System. The egg white-specific IgE values were higher in the positive challenge group than in the negative one (p < 0.01, Mann-Whitney Test). There was a direct proportional relationship between the levels of egg white-specific IgE and the likelihood of positive challenge. Specific IgE values above 1.20 KUA/L could be adequate grounds for delaying the follow-up of egg challenge.