Significant factors associated with severity and outcome of an initial episode of acute urticaria in children.

The aim of this study was to determine the predictive factors of severity and duration of an initial episode of acute urticaria in children. This was a retrospective study of 1120 children of <18 yr who presented to the emergency department (ED) with an initial episode of acute urticaria during the period January 1, 2001, to December 31, 2007. These patients were followed in the ED or outpatient department (OPD) until their symptoms subsided. Variables comprising mild, moderate, and severe urticaria were compared to determine the predictors of severity. The relationships between duration of urticaria and clinical features, including physician-diagnosed causes and treatment modalities, were also analyzed. Significant predictive factors of severity of an initial episode of acute urticaria in children included age, physician-diagnosed causes of urticaria, clinical presentation, coexistent pyrexia or angioedema, and personal allergic history (all p < 0.001). The duration of urticaria was dependent on the physician-diagnosed causes and treatment. Inhalants and unknown causes were predictive of longer duration, while contact materials were associated with shorter duration of urticaria (p < 0.001). Combination treatment comprising an oral plus injectable form of antihistamine or corticosteroid significantly shortened the duration of urticaria compared to single treatment (p < 0.001), especially in children receiving short-term aggressive treatment in the pediatric observation unit (POU) of the ED.