Concomitant Chronic Urticaria in Children: A Distinct Severe Phenotype

Area of Science:

• Pediatrics
• Allergy and Immunology
• Dermatology

Background:

• Chronic spontaneous urticaria (CSU) involves hives/angioedema without a clear trigger, lasting over six weeks.
• Chronic inducible urticaria (CIndU) is a distinct form of urticaria provoked by specific environmental stimuli.
• Concurrent CSU and CIndU in children presents a unique clinical challenge, necessitating differentiation from isolated urticaria types.

Purpose of the Study:

• To characterize pediatric patients with concurrent CSU and CIndU.
• To identify distinguishing factors between concomitant CSU/CIndU and isolated CSU or CIndU.
• To understand the clinical phenotype and treatment needs of children with combined urticaria types.

Main Methods:

• Prospective cohort study conducted over 11 years (2013-2024) at Montreal Children's Hospital.
• Inclusion of pediatric patients (0-18 years) diagnosed with chronic urticaria.
• Exclusion of patients with symptomatic dermographism to focus on other CIndU types.

Main Results:

• Out of 202 pediatric patients with chronic urticaria, 20 (9.9%) had both CSU and CIndU.
• Cold urticaria was the most frequent CIndU in the concomitant group (45%).
• Patients with concurrent CSU/CIndU exhibited more uncontrolled CSU (60%) and higher omalizumab use (20%) compared to isolated urticaria groups.

Conclusions:

• Pediatric patients with concomitant CSU and CIndU represent a more severe phenotype of chronic urticaria.
• This severe phenotype often necessitates advanced biologic therapies, such as omalizumab.
• Understanding these distinctions is crucial for appropriate management and treatment strategies in pediatric urticaria.