Design and Rationale of the OPTIMA Study: Retreatment or Step-Up Therapy with Omalizumab in Patients with Chronic Idiopathic/Spontaneous Urticaria (CIU/CSU). J of Skin [Internet]. 2018 Feb. 23 [cited 2025 Apr. 19];2(S1):S51. Available from: https://skin.dermsquared.com/skin/article/view/296