001643 - Clinical-laboratory evaluation of children with chronic urticaria

To assess the epidemiology, potential biomarkers for severity and treatment response, risks and benefits of oral antihistamine therapy in double or quadruple doses and/or immunobiological treatment, in pediatric patients with chronic urticaria (CU), followed in a Pediatric Allergy and Immunology outpatient clinic.

Observational, prospective study conducted with pediatric patients diagnosed with chronic urticaria, evaluated during follow-up consultations at the clinic. Demographic data, laboratory tests, autologous serum test, provocation tests for induced CU, and current urticaria control were assessed using the Urticaria Control Test (UCT) score.

Twenty-one children with chronic urticaria were included, with a median age at diagnosis of 7 years, 58.1% female, 76.1% with associated induced CU, and 80.9% with associated atopy. Ten patients underwent the autologous serum test, of which 33.3% were positive. No significant differences were found in eosinophil, basophil, d-dimer, total IgE levels, and autologous serum test positivity between controlled versus uncontrolled patients, both among those on quadruple-dose antihistamine and those receiving omalizumab. Only one patient experienced an adverse effect with the use of antihistamine, attributed to possible contamination of the medication with milk in a patient with cow's milk protein allergy. Seven patients, 33.3%, used omalizumab, and none experienced adverse effects with its use.

The presence of autoantibodies, such as a positive autologous serum skin test, suggests that the immunological mechanisms of CU pathophysiology in children are similar to those in adults. The frequency of induced urticaria in our study was higher than in the general population. The use of second-generation antihistamines in quadruple doses and omalizumab appeared to be safe. More data is still needed from the pediatric population to define biomarkers that can predict disease progression and prognosis.The presence of autoantibodies, such as a positive autologous serum skin test, suggests that the immunological mechanisms of CU pathophysiology in children are similar to those in adults. The frequency of induced urticaria in our study was higher than in the general population. The use of second-generation antihistamines in quadruple doses and omalizumab appeared to be safe. More data is still needed from the pediatric population to define biomarkers that can predict disease progression and prognosis.