Is IgG useful for Allergie?

The usefulness of IgG testing for allergies is scientifically controversial. In classical allergology, IgE is the relevant marker for immediate-type (Type I) allergies, while IgG antibodies indicate immune exposure to foods but do not necessarily signify allergy or intolerance. Many commercial IgG tests claim to detect food sensitivities, but evidence is weak: studies show high false-positive rates and poor clinical reproducibility. Professional societies such as the German Society for Allergology and Clinical Immunology (DGAKI) advise against using IgG-based tests for diagnosing food allergies. The provided context does not contain specific information on IgG testing, so this answer is based on general medical guidelines. Reliable allergy diagnosis requires standardized methods like skin prick tests, specific IgE measurement, and oral food challenges. IgG tests may have a limited adjunctive role in some research settings but should not be used alone for dietary recommendations.