CIndU Epidemiology: Prevalence, Subtypes, Diagnosis, and Quality-of-Life Burden

Welcome back to another Dermatology Times Between The Lines series. In "CIndU Epidemiology: Prevalence, Subtypes, Diagnosis, and Quality-of-Life Burden," moderator Diego Ruiz Dasilva, MD is joined by Lindsey Finklea, MD to open the series on chronic inducible urticaria (CIndU).

Dr. Dasilva frames the program around advances in chronic inducible urticaria and data from the phase 3 REMIND study of remibrutinib, presented at EAACI 2026 in Istanbul. Dr. Finklea notes that she has been principal investigator on four pipeline drugs for chronic spontaneous urticaria (CSU) and CIndU. She estimates CIndU prevalence at 0.5% to 1.5% globally, compared with up to 5% for all urticaria combined. The ratio of CSU to CIndU is roughly two or three to one, and 20% to 30% of patients have both conditions. Dr. Dasilva adds that prevalence is hard to pin down when no approved therapy exists, because real-world patients are coded differently or carry several diagnoses. Dr. Finklea says patients often recognize their disease only after a label update and direct-to-consumer advertising.

Symptomatic dermatographism makes up about half of CIndU. Cold and cholinergic urticaria follow, while solar, heat, aquagenic, vibratory, contact, and delayed pressure urticaria are less common, and patients can have more than one subtype. Diagnosis is clinical and begins with a structured history. A vague report such as hives at the beach could reflect dermatographism from sand, solar urticaria, sweating-driven cholinergic urticaria, or delayed pressure urticaria. Many clinics improvise provocation tests with a pen, tongue depressor, ice cube, or hot water. Standardized options include the FricTest 4.0, a temperature test, and pulse-controlled ergometry. Dr. Finklea explains that these tools also track treatment response and set expectations, such as advising a patient with a 10 degrees Celsius threshold to visit Colorado in spring or fall. She calls quality-of-life impact immense and underestimated, citing roughly 30% higher anxiety and depression symptoms and a threefold increase in suicidal ideation.

The next episode in this series, "Living With CIndU: Patient Stories and the Hidden Quality-of-Life Toll," features Dr. Dasilva and Dr. Finklea sharing patient cases and their own personal experiences with urticaria.