Chronic inducible urticaria subtypes in children: Clinical features and prognosis

Chronic inducible urticaria (CIndU) is a subtype of chronic urticaria induced by a physical stimulus.

To evaluate the clinical features, prognostic factors, and natural course of childhood CIndU subtypes.

Patients (1-18 years old, n = 117) diagnosed with CIndU between March 2011 and March 2019 were analyzed. Patients (n = 101) were re-evaluated for the status of their CIndU at least 6 months after the initial evaluation.

The study population comprised of 117 children with a median (inter-quartile range) age of 10.3 (6-14.8) years at admission and a male predominance (53%). Symptomatic dermographism was the most common type of CIndU, affecting 65% of the group, followed by cold urticaria and cholinergic urticaria, which affected 17% and 15.4%, respectively. Baseline serum tryptase levels in cholinergic urticaria and cold urticaria were higher than those in symptomatic dermographism [7.0 (3.3-10.7) μg/L, 4.2 (2.8-9.3) μg/L, and 2.7 μg/L (1.8-5.9), respectively; P = .020]. Recovery was observed in 9.6%, 25.3%, and 34.7% of the CIndU children after 12, 36, and 60 months, respectively. Of the patients with symptomatic dermographism, 40% had remission in 5 years, whereas this rate was only one-fifth in patients with cold urticaria. The worst prognosis was observed in patients with cholinergic urticaria.

This study concluded that nearly one-third of children with CIndU recovered within 5 years and symptomatic dermographism has the best prognosis. Cholinergic urticaria is the CIndU type with the worst prognosis, male dominance, and highest baseline serum tryptase levels.