Pediatric Chronic Urticaria: Clinical and Laboratory Characteristics and Factors Linked to Remission

This study aims to better understand chronic urticaria (CU) in pediatric patients, including its prevalence, clinical characteristics, relevant laboratory findings, and factors linked to remission to improve guidance for management in children.

This study included 185 pediatric patients with an established chronic urticaria diagnosis followed at a single medical center in Barcelona, Spain from January 2015 to November 2021.

Clinical, demographic, and laboratory data were collected for 185 patients; 110 charts were reviewed retrospectively and 75 prospectively. Remission was defined as not requiring treatment while asymptomatic for over 6 months.

Chronic spontaneous urticaria (CSU) (74.6%) was more common than chronic inducible urticaria (25.4%). Atopic comorbidities were found in 35% of patients, of which atopic dermatitis and allergic rhinitis were most common. Pre-existent psychiatric comorbidities were present in 9% of patients. Autoimmune disease was a comorbidity for 8% of patients and was only found in the CSU group. Most patients (64.5%) were prescribed only a standard dose second-generation oral antihistamine but 25.8% needed up-dosing of second-generation oral antihistamines and 9.3% required a biologic. The estimated median time to remission was 36.3 months.

The prevalence of atopic, autoimmune, and psychiatric conditions linked to CU was consistent with results in other pediatric studies. Significant laboratory markers included basopenia and positive basophil activation test, both of which were significantly associated with CSU subtype. Interestingly, autoimmune conditions were exclusively present in patients with CSU subtype. Female gender, associated angioedema, presence of inducible factors, and lower eosinophil count were found to be predictors of prolonged time to remission. Most patients were successfully managed with standard doses of second-generation antihistamines but median time to remission was still about 3 years.

This study confirmed the strong association between atopy and CSU, likely caused by common underlying pathophysiology. It may be worth exploring CU in relation to autoimmune and psychiatric comorbidities. Laboratory work is not currently part of the diagnostic criteria for CSU and further exploration needs to occur to determine clinical relevance of these markers. Standard therapy with antihistamines is largely effective, but CU often takes years to remit. Additional prospective studies with longer follow up time are needed to improve the management of pediatric patients with CU.