Differences between adult and pediatric chronic spontaneous urticaria from a cohort of 751 patients: Clinical features, associated conditions and indicators of treatment response.

Background: Chronic spontaneous urticaria (CSU) is a common disease both in the pediatric and in the adult population. However, there are differences between the two patient populations with respect to etiological factors, comorbidities, and treatment responses. Our aim was to determine differences between pediatric and adult CSU in terms of clinical characteristics, laboratory parameters, comorbidities, response to treatment, and indicators of response.

Methods: A retrospective analysis of CSU patients was performed. Data regarding differences between pediatric and adult CSU patients were analyzed. Indicators of treatment response were determined separately in both pediatric and adult patients.

Results: Of 751 CSU patients (162 pediatrics and 589 adults), female dominancy (48.8% vs. 69.6%) and rate of angioedema (19.1% vs. 59.8%) were lower, and disease duration (5 months vs. 12 months) was shorter in pediatric patients. Anti-TPO positivity (24.7% vs. 9%), elevated CRP (46.5% vs. 11.1%), eosinopenia (38.5% vs. 18.1%), and skin prick test positivity (39.3% vs. 28.8%) were significantly more frequent in adult patients. Response to antihistamines was higher in the pediatric group, and only 7% used omalizumab versus 20.8% in the adults. The comparisons were also performed between <12-year and ≥12-year patients and yielded similar results.

Conclusion: Pediatric CSU shows distinct characteristics such as lower incidence of angioedema and antithyroid antibodies, and it responds better to antihistamines. These suggest that CSU becomes more severe and refractory in adolescents and adults. Adolescent CSU shows features similar to adult CSU rather than pediatric CSU.