Then she may give him a skin or blood test to determine whether the symptoms are due to an immune reaction. If the skin test produces a rash or the blood test shows that he has antibodies to the food, there's a good chance that he's allergic. If the tests are negative, your baby's probably suffering from a food intolerance. At this point, you may be referred to a gastroenterologist to pinpoint the cause of the intolerance. Unfortunately, the shots and immunotherapy methods that treat allergies such as hay fever don't work for food allergies, so avoiding the food is the key to preventing a reaction.
Avoidance is also the best strategy in the case of a food sensitivity.
Although a food sensitivity won't cause a life-threatening reaction, it can make your baby very uncomfortable. Unfortunately, avoiding a particular food is often trickier than it sounds. Foods can show up in unlikely places and even a little bit of something may be enough to trigger a severe reaction. You have to become vigilant about reading food labels, knowing which ingredients to avoid, and asking about ingredients in restaurant dishes. For example, cows' milk and other dairy products show up in canned and processed foods as casein, whey, lactalbumin, caramel color, and nougat, among others.