Tolerance Results and Immune Mechanisms in Cow´s Milk and/or Hen´s Egg Allergic Children Following Natural Evolution or Oral Immunotherapy

Allergy to Cow's milk and hen´s egg proteins are the most common causes of food allergies in early childhood and are associated with the occurrence of adverse events that may be life-threatening, quality of life impairment and negative nutritional and health economic impact. However, contrarily to other food allergy models such as nuts/peanut allergy, milk and egg allergy have greater chances of natural resolution. While around 50% of children may outgrow milk or egg allergy by the age of 5 years old, only 22% of peanut allergic children at the age of 4 years can tolerate this food. However, it is also documented that, at 14 years of age, the persistence of milk and egg allergy still affects around 30% of these children. Standard of care relies on food avoidance and treatment of accidental reactions, but this approach is unsatisfactory because adverse events and quality of life limitations still remain. Milk and egg Oral Immunotherapy (OIT) is the most promising therapeutic alternative and showed good results to induce Desensitization (ability to tolerate the food while it is regularly taken) but insufficient efficacy to achieve Sustained Unresponsiveness (SU) (ability to tolerate the food after a period of avoidance). In the day-to-day practice, families and allergists of milk and egg allergic children frequently face the following dilemma: what is the best approach? Keep waiting for natural resolution or embarking in OIT? At the moment, there are only very limited data to guide this decision, specially in children with mild to moderate allergy, that still after 6 years of age withhold relevant chances of naturally outgrowing their allergy. Our objective is conducting a longitudinal cohort-study of children undergoing food avoidance and children undergoing OIT to assess biomarkers of natural allergy resolution/persistence and OIT Desensitization/Sustained Unresponsiveness trajectories.