Proven Food-Induced Acute Urticaria and Predictive Factors for Definitive Diagnosis in Childhood

Abstract

<b><i>Background:</i></b> Urticaria can be the only sign of a food allergy or can be seen together with other signs and symptoms of a food allergy. <b><i>Objective:</i></b> To determine the demographic, etiologic, and clinical features of food-induced acute urticaria in childhood. <b><i>Methods:</i></b> Patients suspected of food-induced acute urticaria were included in this prospective cross-sectional multicenter study. <b><i>Results:</i></b> Two hundred twenty-nine urticaria cases were included in this study. Seventeen patients who did not meet the inclusion criteria of the study were excluded. Of the 212 included cases, 179 (84.4%) were diagnosed with definitive food-induced acute urticaria. The most common foods causing acute urticaria were cow’s milk, hen’s eggs, and nuts in 56.4, 35.2, and 19% of cases, respectively. The positive predictive value of a history of milk-induced acute urticaria together with a milk-specific IgE &#x3e;5 kU/L for cow’s milk-induced acute urticaria was 92% (95% CI: 81–96%). A history of cow’s milk-induced and/or hen’s egg-induced acute urticaria was consistent with a definitive diagnosis of food-induced urticaria (Chen’s kappa: 0.664 and 0.627 for milk and eggs, respectively). Urticaria activity scores were higher in patients with food-induced acute urticaria (<i>p</i> = 0.002). <b><i>Conclusion:</i></b> Cow’s milk, hen’s eggs, and nuts were the most common allergens in the etiology of childhood food-induced acute urticaria. Although the urticaria activity score provides guidance for diagnosis, an oral food challenge is often essential for the definitive diagnosis of a patient with a history of food-induced acute urticaria.