Phadia’s F4 test is used to detect blood levels of the IgE (antibodies) responsible for allergic reactions to wheat. There is a wide variation in the severity of allergic reactions to wheat depending on its origin and allergen content. A wheat allergy is different from “wheat intolerance” (gluten intolerance or celiac disease). Intolerance is an autoimmune disease that gradually leads to inflammation of the intestinal wall, bowel disorders and malabsorption, often occurring long after wheat consumption. The allergy, however, is an immediate reaction involving IgE antibodies with skin, respiratory, digestive and sometimes cardiovascular symptoms. The interpretation chart accompanying the result expresses the probability of an allergic reaction to wheat, but not necessarily the severity of the reaction. Case history and clinical examination by the physician are essential for a reliable interpretation of the results.
A negative anti-wheat IgE result (< 0.35 kU/L) indicates that wheat is probably not responsible for the symptoms reported by the person, but it DOES NOT COMPLETELY RULE OUT THIS POSSIBILITY. All negative and positive results must be interpreted in light of the case history. The double-blind oral food challenge remains the definitive technique for confirming a food allergy.