The Chronic Reality of CSU

A practical discussion of how to recognize CSU, reassess inadequate antihistamine response, and build a more intentional path toward long-term control.

By the time many patients with chronic spontaneous urticaria (CSU) reach dermatology, they have already cycled through urgent care visits, repeated corticosteroid bursts, and an exhausting search for a trigger that may never emerge. In this installment of Topical Conversations, Dawn Merritt, DO, and Naiem Issa, MD, PhD, move the discussion beyond recognizing the burden of CSU and into the practical work of diagnosing it, setting expectations, and building a long-term treatment plan.  

Dr Issa walks through a focused approach to distinguishing CSU from inducible urticaria, including questions about heat, exercise, cold, water, pressure, and dermatographism. Just as important is the reassurance that begins the visit. “Welcome to your destination,” he tells patients—a signal that their disease can be understood and managed, rather than promising some immediate fix.

From there, the conversation turns to what happens when appropriately dosed second-generation H1 antihistamines aren’t enough. Drs Merritt and Issa connect mast cell activation and type 2 inflammation to the evolving treatment landscape, then consider how route of administration, dosing burden, anticipated response, and patient preference can shape shared decision-making. As Dr Merritt puts it, “The skin exam captures a moment, but our patient history captures the disease.”

It’s a grounded discussion about moving past episodic rescue and toward a more deliberate approach that recognizes CSU as a chronic, relapsing-remitting disease and gives patients a clearer path toward sustained control.