Is IgG Unverträglichkeitstest useful for allergy?

IgG food intolerance tests are often marketed as allergy tests, but they are not scientifically valid for diagnosing allergies or true intolerances. True allergies involve IgE antibodies, which trigger immediate symptoms like hives or anaphylaxis. IgG antibodies, in contrast, are normal memory antibodies produced after exposure to many foods—their presence simply indicates prior contact, not necessarily a pathological reaction. Major medical organizations, including the European Academy of Allergy and Clinical Immunology, advise against IgG-based testing because it leads to false positives and unnecessary dietary restrictions. The evidence base is weak: no controlled trials demonstrate clinical benefit. Instead, these tests can cause malnutrition, anxiety, and wasted expense. If a food allergy is suspected, an IgE test (skin prick or specific IgE) under medical supervision is appropriate. For true intolerances (e.g., lactose intolerance), more specific tests like the hydrogen breath test are indicated. In summary, IgG tests are not useful for allergy diagnosis and are not recommended by evidence-based medicine.