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

ABSTRACT 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 H 1 ‐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.