D3.29 - Detailed Clinical Characterization of a Large Cohort of Chronic Spontaneous Urticaria Patients

Chronic spontaneous urticaria (CSU) is often debilitating, yet there is limited data on the typical clinical profile. The diversity of presentations and advancements in treatment underscore the need for a comprehensive characterization of CSU.

A retrospective chart review was conducted across four allergy practices, gathering a minimum of six months of demographic, medication and symptomatology data on 400 patients (211 adult, 189 pediatric) with CSU.

Disease severity was evenly distributed, with 97 patients classified as mild, 111 as moderate, and 192 as severe. Adults were diagnosed at an average age of 46 years compared to 8 years for pediatric patients. A substantial proportion of patients presented with atopic comorbidities, including allergic rhinitis (72%), asthma (38%), and atopic dermatitis (17%). Notably, 43% of patients had two or more type-2 inflammatory comorbidities, highlighting the potential complexity of their clinical profiles. Symptomatology was as follows: itching was reported in 193 cases, swelling was reported in 121 patients, red rash was present  in 376, and 142 noted that rash was limited to or more commonly on their lower extremities.

For H1 antihistamines, cetirizine was most frequently prescribed, to 308 patients, of whom 27.6%were non-responders. Other common treatments were fexofenadine (143 patients, 35.6% non-responders), diphenhydramine (134 patients, 32.1% non-responders), hydroxyzine (99 patients, 46.5% non-responders) and levocetirizine (76 patients, 23.7% non-responders). 

Topical steroids, including triamcinolone 0.1% (39 patients, 23.1% non-responders) and hydrocortisone 1% (14 patients, 42.9% non-responders), were utilized the least. A negligible portion of the study population (<20) patients trialed other topicals, such as clobetasol and tacrolimus, with outcomes largely unquantified. 

Omalizumab was administered to 146 patients, with 35 patients experiencing either no response or partial response to this therapy. The non-responder rate was 14.9%, compared to 9.9% partial responders. Of 154 total patients who were prescribed prednisone for comorbid asthma attack, 124 were complete to partial  responders, and 76% reported their symptoms returned after stopping the OCS.

The frequent prevalence of atopic comorbidities and refractory urticaria in CSU patients highlights a significant unmet need for effective systemic treatments, particularly in cases driven by type-2 inflammation.