The clinician should use specific IgE tests (skin prick, serum tests, or both) to foods as diagnostic tools; however, testing should be focused on foods suspected of provoking the reaction, and test results alone should not be considered diagnostic of food allergy. When we hear the word “food allergy” we are often referring to IgE-mediated food allergy. This is the type of food allergy that occurs immediately, often within the first hour of ingestion of a food and can be life-threatening. Symptoms may include hives, swelling, wheezing, cough, shortness of breath, vomiting, abdominal pain, lethargy, change in mood or a drop in blood pressure. IgE is a type of antibody that can rapidly bind to food proteins leading to release of histamine and other chemicals from allergy cells which lead to rapid symptoms. The clinical history is most important when evaluating an adverse food reaction. Skin prick tests, serum specific IgE blood tests to foods, or both can be used to support a diagnosis of IgE-mediated food allergy. It is important to understand that false positive skin and blood tests are common and a positive skin test or blood test must be used along with the clinical history to make a diagnosis. At times when the history is unclear, an oral food challenge can be done. This involves eating the suspected food slowly under supervision of a board certified allergist/immunology.
- 03 May 2015