Food allergy means that an antibody called IgE (stands for immunoglobulin E) binds to food and causes a reaction in the body. The reaction commonly manifests in hives, skin rashes, stomach aches, nausea/vomiting, and more seriously, swelling of the throat and “anaphylaxis” which can be life-threatening.
Food sensitivities are mediated by different antibodies than a Food Allergy. A Food sensitivity happens when an antibody, IgG or IgA, binds to a food and causes a reaction in the body. Usually this type of reaction is not as immediate as food allergy, but may occur from 2-3 hrs to days after ingesting the food. The reaction may cause inflammation in the body. Many people people report feeling fatigue (especially a few hours after eating), congestion, joint pain (especially in the lower back), stomach aches, constipation, diarrhea, and general malaise.
The most common food sensitivities you’ll hear about is gluten and dairy sensitivity. In my practice, I often see find dairy food sensitivity linked to stuffy nose and congestion, frequent ear infections, sinus problems and even allergy-like symptoms, such as itchy throat and puffy, dark under eye circles. See gluten sensitivity and celiac disease HERE.
Testing can be done for food allergy by your child’s allergist/immunologist or pediatrician. It can be done by a skinprick test or by a blood test.
Specialized testing can also be done for food sensitivity. This may include IgG and IgA food sensitivity testing by blood and stool, respectively. The gold standard for detecting food sensitivity, however, is the food elimination diet. This elimination diet may be very difficult and the child should be followed by a dietitian closely.