INTRODUCTION
Chronic inducible urticaria (CIndU) is a subset of chronic urticaria (CU) in which a specific trigger eliciting the hives is identified1. Cold urticaria (coldU) is a type of CIndU characterized by pruritic wheals and/or angioedema triggered by exposure to cold air, liquids, or objects2. The pathogenesis of coldU is not well understood. It is postulated that cold exposure triggers de novo autoantigen formation, which triggers IgE-mediated mast cell degranulation and release of inflammatory mediators leading to wheals and/or angioedema3. ColdU is the main type of CU known to cause anaphylaxis3.
The point prevalence of coldU is estimated to be 0.056% (95%CI: 0.016, 0.112)4, which may inversely correlate with the average temperature of the country of residence. The diagnosis of coldU consists of provocation testing using an ice cube or the TempTest, which determines the threshold temperature at which symptoms develop5. Treatment consists of avoiding cold triggers, second generation H1-antihistamines (sgAHs) up to four-times the standard dose, and, in recalcitrant cases, off-label use of omalizumab may be considered4,5. It is suggested that the resolution rate of coldU is low, with fewer than half (44.5%) of adult patients experiencing symptom resolution in 10 years6. Although coldU predominantly manifests in young adults, 27% of cases begin in childhood and these cases are less likely to experience symptom resolution6. Cold-induced anaphylaxis is reported in up to 36.7% of children with coldU7. However, there are scarce data published on pediatric coldU. We aimed to assess the clinical characteristics, comorbidities, management, risk of anaphylaxis, and natural history of coldU in a cohort of children. Additionally, we sought to compare the presentation and resolution rate of pediatric coldU to chronic spontaneous urticaria (CSU).