Which diagnostic tests are most effective for confirming food allergies in adults?

The most effective diagnostic tests for confirming food allergies in adults are skin prick testing and serum-specific immunoglobulin E (IgE) testing. Skin prick testing involves introducing allergen extracts into the skin and observing for a reaction after 15 minutes, which indicates sensitization to the allergen. This test is sensitive but not specific and must be interpreted alongside the clinical history. It requires healthcare professionals with appropriate training and facilities to perform and interpret the test safely, including the ability to manage anaphylaxis if it occurs. Serum-specific IgE testing measures IgE antibodies to specific food allergens in the blood and is useful when skin prick testing is not possible or results are equivocal. However, it also cannot distinguish between sensitization and true clinical allergy and may take days to weeks for results. Both tests have limitations, including false positives and negatives, and should not be used indiscriminately for large panels of allergens due to high false positive rates. If test results do not correspond with the clinical history, an oral food challenge under medical supervision is considered the gold standard for diagnosis, involving gradual ingestion of the suspected allergen to confirm or exclude clinical allergy.

Atopy patch testing and serum-specific IgG testing are not recommended for diagnosing food allergy.