Diagnostic Delay in Patients With Chronic Urticaria: Results From the Chronic Urticaria Registry (CURE)

Background: Chronic urticaria (CU) diagnosis includes the patient's clinical history and physical examination. However, atypical presentations or misdiagnosis can lead to diagnostic delay (DD). Objective: The impact and contributing factors of DD in CU are unknown and were assessed in the present study. Methods: We retrospectively analysed data from CU adult patients from the international, multicenter Chronic Urticaria Registry (CURE). Results: Of 4332 CU patients, 61% had standalone chronic spontaneous urticaria (sCSU), 18% had ≥ 1 form of chronic inducible urticaria (CIndU), and 21% had a combination of both (CSU + CIndU). Diagnosis of CU was delayed in 24% of patients by at least 1 year. CIndU patients showed a longer DD compared to those with sCSU or CSU + CIndU (median, [IQR]: 4, [0–22] vs. 1, [0–6] vs. 2, [0–9] months, p < 0.001). Among CIndU patients, symptomatic dermographism (n = 264) and cholinergic urticaria (n = 103) patients had the longest DD compared to all other CIndU subgroups (median: 4 months, p = 0.005 for both). In CIndU patients, a longer DD was associated with having an additional CIndU (OR: 12.8, p = 0.03), younger age, comorbidities, lower disease control, and lack of second-generation H₁-antihistamine treatment. In CSU patients, a DD of ≥ 6 months was associated with lower CSU activity (median weekly Urticaria Activity Score of 14 vs. 21, p = 0.02) compared to that of DD < 6 months. Conclusions: Diagnosis of CU is delayed in one out of four patients. Greater awareness of the guideline-recommended CU classification, clinical presentation, and diagnostic work-up can facilitate CU diagnosis.