Skip to contentSkip to navigation
COVID-19: We are open. Some services are modified. Mask is mandatory. Details at


Phadia’s F40 test is used to detect blood levels of the IgE (antibodies) responsible for allergic reactions to tuna. People with allergies to tuna may have cross allergies with other fish (cod, hake, mackerel, etc.) but, unless there is a true double allergy, they will not necessarily be allergic to crustaceans and other seafood. The interpretation chart accompanying the result expresses the probability of an allergic reaction to tuna (and possibly other fish), but not necessarily the severity of the reaction. Case history (symptoms, relation to fish consumption, etc.) and clinical examination by the physician are essential for a reliable interpretation of the results.

A negative anti-tuna IgE result (< 0.35 kU/L) indicates that tuna is probably not responsible for the symptoms reported by the person, but it DOES NOT COMPLETELY RULE OUT THIS POSSIBILITY. Both 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 tuna allergy. Unlike milk and egg white allergies, the hypersensitivity to tuna and other fish often develops in adulthood and tends to persist for life.

Term of the Week

Hot zone

A hot zone is a section of a facility (sometimes an entire facility or even a city district) where there is a high risk of contamination by patients with an infectious disease. All individuals entering a hot zone must respect appropriate protective measures. By analogy, “cold zone” and “warm zone” are used to refer to areas where there is no infected individual or only individuals suspected of having an infection.