Evidence check: HbA1c in the context of Allergie

HbA1c (glycated hemoglobin) is a well-established marker for average blood glucose over 2–3 months, primarily used for diabetes diagnosis and monitoring. There is no direct evidence linking HbA1c to allergies. Allergic conditions such as asthma or hay fever may involve chronic low-grade inflammation that could theoretically affect glucose metabolism and HbA1c levels, but the evidence is weak and purely mechanistic. No validated thresholds or screening guidelines exist for using HbA1c in allergy contexts. Consumer tests that include HbA1c in an 'allergy panel' are not evidence-based. Important caveats: HbA1c can be influenced by iron deficiency, kidney disease, or hemoglobin variants, leading to false interpretations. For allergy assessment, specific IgE testing or skin prick tests remain the gold standard. Therefore, HbA1c should not be used as a marker for allergies.