TPO and urticaria: In CSU, although several variables (e.g., D-dimer, basophils, IgG anti-TPO) have been associated with the response to antiH1, none seem to have sufficient precision to predict the clinical response to this treatment [28, 31] and although several studies show a statistical association with outcomes of interest in urticaria, their diagnostic (sensitivity, specificity) or predictive (calibration, discrimination) performance has not been evaluated, which limits their clinical applicability.