Type I and type IIb autoimmune chronic spontaneous urticaria: Using common clinical tools for endotyping patients with CSU.

Background: Mechanisms triggering the pathogenesis of chronic spontaneous urticaria (CSU) have been identified as type I autoallergic (which is associated with IgE antibodies against autoantigens) and type IIb autoimmune (which is driven by autoantibodies to FceR1 and/or IgE).

Objective: Our aim was to define presumptive endotypes in patients with CSU by using tests amenable to use in routine clinical practice.

Methods: A retrospective analysis of the medical records of 394 patients with CSU with or without chronic inducible urticaria or angioedema was performed.