For people who are parenting kids with food allergies, it is a good idea to keep up with the latest medical developments in this area because the science is changing. The conventional wisdom once held that infants with food allergies should avoid the foods at all costs unless they outgrew them, but the new thinking is that the best way to treat allergies is to "desensitize" infants by exposing them to the allergen in small increments over time.
Food allergies come and go over time, and kids tend to outgrow many of them sooner or later. The bad news is that new ones can strike at any point, and old ones can also return. So once they do outgrow an allergy, it is important to keep feeding them that food on a regular basis as this is the best way to ensure the allergy does not return.