A food allergy is an abnormal immune reaction to a particular food item. According to MayoClinic.com, food allergies affect approximately 6 to 8 percent of children under the age of 3. The most common food allergies in infants and children are eggs, milk, peanuts, shellfish, soy, tree nuts and wheat.
Physiology
When your body comes into contact with a potentially harmful substance, your immune system creates proteins called antibodies. Antibodies attach to the potentially harmful substance and destroy them. The next time you are exposed to that particular substance, your body recognizes it immediately and triggers a widespread immune response to protect your body from harm.
When an infant has a food allergy, his body mistakenly deems a particular food item as a potentially harmful substance. The immune system creates antibodies called immunoglobulin E, or IgE, which attempt to get rid of the food item. The IgE antibodies trigger the release of histamine, which causes widespread inflammation. The inflammation caused by histamine is responsible for the symptoms commonly associated with allergic reactions.
Symptoms
Symptoms of an allergic reaction usually begin immediately. Possible symptoms of a food allergy in an infant include hives, swelling of the lips, face or tongue, wheezing, difficulty breathing, diarrhea and vomiting.
If an infant is severely allergic to a particular food item, consumption of that food may result in tightening of the airways, shock, rapid pulse and loss of consciousness.
Treatment
To avoid the symptoms of a food allergy, it is important to make sure that the infant does not consume or come into contact with the food to which he is allergic. There is no way to cure a food allergy, but most infants outgrow allergies as they age.
If an allergic reaction occurs, over-the-counter antihistamines that are approved for babies and infants may help reduce swelling and improve symptoms. In the case of a life-threatening reaction, injections of epinephrine and emergency medical treatment are necessary.
Treatment
The most common food allergy in an infant is an allergy to cow's milk. According to the University of Maryland Medical Center, infants are thought to be susceptible to a cow's milk allergy because their immune and digestive systems are not fully developed. A milk allergy can develop within days of birth, but usually goes away by the age of 3.
Delaying the introduction of solid food into an infant's diet until after the age of 6 months can help prevent food allergies. The American Academy of Pediatrics recommends delaying adding eggs into the diet until the age of 2 and not introducing peanuts, tree nuts and fish until the age of 3.
