PURPOSE OF THE STUDY.
To assess the incidence of food allergies and identify risk factors for the development of food allergies in infants.
The study population was part of the Adana Pediatric Allergy and Risk Factor (ADAPAR) birth cohort study in Adana, Turkey. From February 2010 to February 2011, 1475 infants born at a single center were enrolled. Infants were followed from birth until 1 year of age.
At birth, umbilical cord blood was collected, and infants were examined. The infants returned for study visits at 3, 6, and 12 months of age. The subjects’ mothers completed questionnaires at birth, at each study visit, and over the phone at 9 months. Skin prick testing (SPT) and serum-specific IgE levels (SSIgE) (cow’s milk, hen’s egg, soy, wheat, fish, and peanuts) were measured at 6 and 12 months of age. Additional testing was done at 3 and 9 months when there was suspicion of allergic disease. Food allergy (based on clinical history, positive SPT, or positive SSIgE) was confirmed with standardized oral food challenge (OFC).
Of the 1475 study subjects recruited at birth, 1377 infants were enrolled, and 920 had available SSIgE and/or SPT results. While 90 infants (6.5%) were noted to have reactions suspicious for food allergy, a diagnosis of food allergy was confirmed in 33 of 1377 infants (2.4%). Thirty-two of the 33 infants had a positive OFC, and 1 infant had a clinical history consistent with anaphylaxis to milk. The most frequent symptoms reported during OFC were cutaneous (74%, n = 28) and gastrointestinal (18%, n = 7). The most common allergens confirmed by OFC were milk (51.3%, n = 20) and egg (43.7%, n = 17). Infants with confirmed food allergy were significantly more likely to have the following characteristics compared with infants without food allergies: male sex, atopic dermatitis, history of wheezing, and family history of atopy. Multivariate regression analysis showed that having a food-allergic sibling significantly increased the risk for food allergy (OR 18.9, 95% CI 1.59–224.05).
Food allergy was confirmed in 33 (2.4%) of these infants. The most common food allergy was milk followed by egg, and the most frequent symptom during a positive food challenge was cutaneous. A sibling with food allergy was a significant risk factor for the development of food allergies in infancy.
This study adds further insight into the characteristics of food allergy in infants with milk and egg allergy being diagnosed as early as 3 to 4 months of age. Worsening eczema was included as an indicator of a positive food challenge; however, it is unclear if eczema was measured objectively, and thus, true IgE-mediated allergy to food may have been overestimated. The timing of food allergy onset is of interest in the setting of an increasing focus on food allergy prevention by intervening during infancy.
- Copyright © 2017 by the American Academy of Pediatrics