Chronic spontaneous urticaria remission definition and therapy stepping down: World Allergy Organization position paper.

Background: There is no global agreement on the definition of chronic spontaneous urticaria (CSU) remission.

Objective: Our aim was to generate a consensus for clinical definitions of CSU-related terms focused on remission.

Methods: The World Allergy Organization Urticaria Committee systematically reviewed current available longitudinal articles. On the basis of this review, a consensus agreement was reached for the definition of the term CSU remission. In addition, a scheme specifying when and how therapeutic de-escalation should be performed was constructed.

Results: Almost all of the groups that have carried out longitudinal studies to evaluate the frequency of CSU remission agreed to use the term CSU remission if the patient remains without urticaria signs and symptoms without pharmacologic treatment (omalizumab, cyclosporine, antihistamines, or systemic corticosteroids). According to our systematic review, the available evidence does not specify the best time to consider CSU remission. However, current evidence suggests that there is no 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 or mechanistic remission in CSU or identifying patients with a high probability of cure. It can be reasonable to consider a reduction of treatment after 6 months of CSU control, with evaluation 2 to 6 months after stepping down treatment.

Conclusion: The World Allergy Organization Urticaria Committee proposes defining CSU clinical remission based on the total resolution of urticaria signs and symptoms without pharmacotherapy for at least 6 months. The implications of this definition in clinical practice must be evaluated and validated in future studies.