Phadia’s F345 test is used to detect blood levels of the IgE (antibodies) responsible for allergic reactions to macadamia nuts. The IgE detected in the test may be specific to macadamia nuts or involved in cross allergies with other nuts (walnuts, Brazil nuts, hazelnuts, etc.), while others may be applicable to both nuts and peanuts. The interpretation chart accompanying the result expresses the probability of an allergic reaction to macadamia nuts, but not necessarily the severity of the reaction. Case history (symptoms, relation to meals, snacks, etc.) and clinical examination by the physician are essential for a reliable interpretation of the results.
A negative anti-macadamia nut result (< 0.35 kU/L) indicates that macadamia nuts are 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 the presence or absence of a food allergy. In most cases, allergies to macadamia nuts and other nuts are persistent, but it has been shown that some people may get over them.