Urticaria in a Pediatric Population: A Portuguese Single-Center Cohort Report

Background Urticaria typically involves the skin and mucosa and is characterized by the development of wheals, angioedema, or both. According to the temporal evolution of the lesions, urticaria is classified as acute (AU) or chronic (CU), depending on whether the episodes last for fewer or more than six weeks, respectively. This study aimed to characterize a group of children and adolescents with urticaria and describe its subtypes, associated comorbidities, treatment, and evolution.Methodology This retrospective, observational study included patients aged <18 years who were diagnosed with urticaria in a tertiary teaching hospital in Portugal, and followed up in a Pediatric Allergy Unit, between January 2019 and December 2021.Results A total of 43 patients, aged nine months to 16 years were included. Of these, 22 (51%) were males. AU was identified in 12 (28%) cases, chronic spontaneous urticaria in 21 (63%), and physical urticaria (to cold) in four (9%). Autoantibodies were detected in four patients with spontaneous urticaria. In 6% of patients with CU, the episodes were associated with angioedema. Most CU episodes were successfully managed with the recommended or double the recommended dose (48%) of H1 antihistamines. Three patients requiring fourfold higher than the recommended dose of H1 antihistamines remained unresponsive and were started on omalizumab. Associated autoimmune thyroiditis was diagnosed in four patients.Conclusions In this cohort of patients, urticaria was equally distributed between the genders and the first-line therapy was second-generation antihistamines, consistent with current guidelines. Universal screening for autoimmune diseases in patients with chronic spontaneous urticaria revealed four cases of thyroiditis, which supports the relevance of this approach when managing CU.