Children may develop food allergy by consuming a food directly or through nursing where they may become allergic to something moms may have eaten. To prevent food allergies, it is recommended to introduce solids gradually in a child’s diet between ages of four to six months and pay attention to any signs and symptoms that may manifest themselves when you introduce a particular food. One should start with rice cereal, followed by barley and oat cereal and them move on to yellow vegetables, fruits, green vegetables, meats and at last, wheat. Keep a gap of five to seven days before moving on to another food, so you can watch whether any symptoms such as incessant crying, rash, diarrhea or vomiting, develop during this period. If they do, you may call the doctor.