Chronic spontaneous urticaria remission definition and therapy stepping-down. WAO Position Paper

Background: There is no global agreement on the definition of Chronic Spontaneous Urticaria (CSU) remission.

Objective: To generate a consensus for clinical definitions in CSU focused on remission.

Methods: The World Allergy Organization (WAO) Urticaria Committee systematically reviewed current available longitudinal articles. Based on this review, a consensus agreement was reached for the CSU "remission" definition. Additionally, a scheme was constructed for when and how therapeutic de-escalation should be done.

Results: Almost all groups that have carried out longitudinal studies to evaluate the frequency of CSU remission agreed to use this term if the patient remains without urticaria signs and symptoms without pharmacologic treatment (omalizumab, cyclosporine, antihistamines or systemic corticosteroids). After our systematic review, the available evidence does not define the best time to consider CSU remission. However, current evidence suggests that there is not a significant difference in CSU relapse between 6- and 12-month periods of remission. So far, no evidence exists to propose any biomarkers for defining inflammatory/mechanistic remission in CSU or identifying patients with a high probability of cure. It can be reasonable to consider a reduction of treatment after six months of CSU control, with evaluation 2 to 6 months after stepping-down treatment.

Conclusion: The WAO Urticaria Committee proposes defining CSU clinical remission based on the total resolution of urticaria signs and symptoms without pharmacotherapy for at least six months. The implications of this definition in clinical practice must be evaluated and validated in future studies.