Fecal Calprotectin as a Biomarker of Food Allergy and Disease Severity in Children with Atopic Dermatitis without Gastrointestinal Symptoms.

Fecal calprotectin (FCP) is a biomarker of intestinal inflammation and has recently been proposed as a diagnostic biomarker of food allergy (FA) in children. The aim of this study was to compare FCP level in infants and children under 4 years old with 1) atopic dermatitis (AD) with food allergy (FA) and 2) children with AD and without FA with the results in healthy controls. In total, 46 infants and children (mean age 14 months ± 12) diagnosed with AD were divided into two groups: G1, children with atopic AD with FA (n=28) and G2, children with AD without FA (n=18). The control group (G3) was made up of healthy children of the same age (n=18). The median FCP was significantly higher in G1 compared with G2 (G1: median 154, IQR 416 µg/g vs G2: median 41.3, IQR 59 µg/g; P=0.0096). The median FCP in children with AD and FA was significantly higher before elimination diet in comparison with FCP after 3 months of elimination diet (median 154, IQR 416 µg/g vs median 35, IQR 23 µg/g; P=0.0039). The level of FCP was significantly positively correlated with the SCORAD score (r=0.5544, P=0.0022). Our study showed a significant difference in level of FCP in patients with AD without FA compared with patients with AD and FA. We also found a positive correlation of FCP with SCORAD score, a biomarker of AD severity. New studies are needed to investigate the role of FCP as a biomarker of FA in children with AD.