Evidence check: TSH in the context of Allergie

The link between TSH (thyroid-stimulating hormone) and allergies is not well-established in evidence-based medicine. TSH is primarily a marker of thyroid function. Some observational studies suggest a possible association between thyroid autoimmunity (e.g., Hashimoto's thyroiditis) and allergic conditions such as asthma or atopic dermatitis. However, these associations are weak, not causal, and confounded by factors like age, sex, BMI, and medication use. TSH alone is not a validated biomarker for allergy. In clinical practice, TSH is not used for allergy diagnosis. Commercial tests that include TSH in an 'allergy check' often overstate the evidence. A proper allergy workup (history, IgE testing, skin prick tests) is essential. The evidence for a direct TSH-allergy connection is best rated as 'human-moderate' or 'mixed', based on observational studies. Consumers should not rely on TSH levels to diagnose or manage allergies.