Diagnosing the Hallmark Signs and Symptoms of CSU

Welcome back to another HCPLive Peers & Perspectives series. In this episode titled “Diagnosing the Hallmark Signs and Symptoms of CSU,” moderator Andrea Nguyen, DMSc, MPAS, PA-C, discusses chronic spontaneous urticaria (CSU) with Matthew Zirwas, MD. The episode opens with the moderator asking the panelist to describe the hallmark signs of CSU and the patient population most affected. The panelist explains that CSU is defined by spontaneously appearing hives that present as raised, red wheals surrounded by a blanched halo, can occur anywhere on the body, and typically resolve and recur unpredictably. He notes that roughly one-third of patients also develop angioedema, deep tissue swelling that commonly affects the lips, face, or hands. While CSU can occur at any age, including in children and older adults, onset is most common among women in their 20s and 30s.

The panelist highlights a strong association between CSU and autoimmune thyroid disease, recommending that patients have anti-thyroid peroxidase antibodies checked and, regardless of the result, undergo annual TSH monitoring for life, since elevated thyroid risk often develops over time even when initial testing is normal. He frames CSU for patients as an autoimmune condition that raises susceptibility to other autoimmune diseases, helping set expectations for long-term monitoring.

The conversation also touches on the well-documented female predominance of CSU, cited at roughly a 2-to-1 ratio in published literature, though clinical impression in practice can skew even more heavily toward women, possibly reflecting differences in care-seeking behavior between sexes. Population-based estimates, including a recent claims-data analysis, place CSU prevalence at approximately 0.78%, translating to several million affected Americans. The panel underscores that despite being common and burdensome, CSU is frequently underrecognized in clinical practice, setting the stage for a deeper discussion of diagnostic nuances ahead. In the next episode, “Distinguishing CSU From Chronic Inducible Urticaria Subtypes,” the panel explains how to tell true inducible urticarias apart from CSU with an inducible component, and why getting that distinction right protects patient access to effective therapy.