Finfish allergy blood testing is used to diagnose an allergy to finned fish such as salmon, tuna, cod, and other species. It measures the body’s immune response, particularly the production of specific antibodies (IgE), to finfish proteins. If you are allergic to finfish, your immune system reacts to certain proteins in the fish, which can cause symptoms ranging from mild itching to severe anaphylaxis.

Types of Blood Tests for Finfish Allergy

  1. Specific IgE (sIgE) Testing
    • This test measures the levels of IgE antibodies in your blood that are specific to different types of finfish proteins.
    • Our tested fish include:
      • Codfish
      • Mackerel
      • Plaice
      • Sardine/Pilchard
      • Salmon
      • Sole
      • Swordfish
      • Tuna
    • A positive test indicates that your immune system has produced IgE antibodies against finfish proteins, suggesting an allergy. However, this test alone is not sufficient for a diagnosis; it must be combined with clinical history and possibly other tests.
  2. Component-Resolved Diagnostics (CRD)
    • This more advanced test analyses specific protein components (allergens) of the fish to identify which proteins you are allergic to. It provides greater accuracy, especially for determining cross-reactivity between different species of fish.
  3. Total IgE Test
    • This measures the total amount of IgE antibodies in your blood. Elevated IgE levels can indicate an allergic tendency, but it doesn’t specify the allergen.

How the Test Works:

  1. A blood sample is taken and sent to a lab.
  2. The lab tests for specific IgE antibodies to various finfish allergens.
  3. Results are typically expressed in numerical values that correlate with the likelihood of a true allergy:
    • Class 0: No detectable IgE
    • Class 1-6: Increasing levels of IgE, indicating increasing probability of allergic sensitivity.

Cross-Reactivity and Considerations

  • Cross-Reactivity: Many people allergic to one type of finfish may react to others due to similar protein structures. However, some may tolerate certain species better than others.
  • Shellfish vs. Finfish: Being allergic to finfish doesn’t mean you will also be allergic to shellfish (such as shrimp or lobster), as these allergies are triggered by different proteins.

Diagnosis and Management

  • A finfish allergy diagnosis is confirmed through a combination of IgE test results, clinical history, and sometimes an oral food challenge under medical supervision.
  • If diagnosed, complete avoidance of finfish is typically recommended. In severe cases, carrying an epinephrine auto-injector (EpiPen) is advised in case of accidental exposure.

Blood testing for finfish allergies helps guide proper diagnosis and management, reducing the risk of severe allergic reactions. If you suspect a finfish allergy, consult with an allergist for further evaluation.

Results – 2 days from Laboratory receiving sample

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