Role of the skin patch test in diagnosing food allergy in children with atopic dermatitis

The aim of the study was to determine peculiarities of food allergy in children with atopic dermatitis and to evaluate the significance of skin patch test in determining the main food allergens. Methods. One hundred and eight children (57 boys and 51 girls) with atopic dermatitis were examined. Atopic dermatitis was diagnosed by standard diagnostic criteria, severity of the progress of the disease was determined using SCORAD index and the amount of total IgE in blood, skin prick and patch tests with the main food allergens were performed. Results. The age of the patients varied from 6 months to 16 years, however, almost half (41%) of them were toddlers (1–3 years old). Mild form of atopic dermatitis was dominating (52%). Analysis of the total IgE amount in blood showed different degree of sensitivity of the children tested. Normal amount of the total IgE in blood was found in 73.1% of children with atopic dermatitis, and the increased total IgE amount was found only in 26.9% of children. Positive skin prick test with the standard and the most common food allergens was found only in 4.63% of children with atopic dermatitis, while the positive skin patch test with 25 food allergens was found in 68.5% of children. Depending on the type of the allergic reaction, immediate type reaction dominated only in 10.3% of children with atopic dermatitis, while the delayed type allergic reactions were characteristic to food allergies in 48.3% of children with atopic dermatitis. Food allergy was not found in one fifth of children with atopic dermatitis. Conclusions. Skin patch test is an informative and reliable diagnostic test in evaluating the delayed type allergic reactions. In about half of the tested persons with atopic dermatitis, food allergy appeared in delayed type allergic reactions. Therefore it is very important to do the skin patch test for toddlers and pre-school age children. [...]