Food Sensitization in Early-Onset AD Linked With Later Allergic Respiratory Diseases

Pediatric patients with early-onset atopic dermatitis (AD) who reported incidence of food sensitization were associated with later allergic respiratory diseases, according to study findings published today in Revue Française d'Allergologie.

Characterized by the progression of atopic disorders, the widely prevalent concept called atopic march explains the pattern in which AD developed in children is later followed by food allergies, allergic rhinitis, and allergic asthma.

Several prospective birth cohorts have shown that there is an association between early-onset AD and the development of allergic rhinitis and asthma at school age, in which sensitization to immunoglobulin E (IgE) may increase risk of developing these conditions.

“Atopy is defined as a personal and/or familial propensity to produce IgE antibodies and sensitization in response to allergen exposures. The major food allergens in pediatric patients with AD include egg whites, cow’s milk, soy, wheat, and peanuts,” explained the study author.

In seeking to further investigate the course of allergic diseases in pediatric patients with early-onset AD, a single-center restrospective cohort study of data derived from Diyarbakır Children’s Hospital in Turkey was performed. Patients between 3-7 years of age with AD in the first 2 years of life and control counterparts (N = 211) were examined for the diagnosis of wheezing, AD, and allergic rhinitis from the hospital database and government e-health service.

The study cohort included 119 children diagnosed with AD between the ages of 0-2 in 2013 (mean [SD] age, 12.1 [7.3] months; 60.5% male; mean [SD] serum total IgE level, 157.9 [232.5] kU/L) and 92 children of the control group aged 0-3 months who had a hearing test for screening in the same year.

Between the 2 groups, mean blood eosinophil count was shown to be significantly higher in the AD group vs control group (738/mm³ vs 364/mm³; P < .001). Frequency of at least 3 wheezing attacks was also significantly higher in the AD group vs control for children under 2 years old (17.6% vs 4.3%; P = .002), whereas frequency of at least one wheezing attack (28.6% vs 29.3%), at least 3 wheezing attacks (15.1% vs 9.8%), and allergic rhinitis (22.7% vs 22.8%) were not significantly different between the AD and control groups in children 3-7 years old.

However, findings further showed that in the AD group, the frequency of at least 1 wheezing attack (42.6% vs 19.4%; P = .006), at least 3 wheezing attacks (25.6% vs. 8.3%; P = .011), and allergic rhinitis (38.3% vs 12.5%; P = .001) were significantly higher in children with food sensitization than individuals without food sensitization.

Although frequency of persistent AD was not significantly different between those with and without food sensitization (19.1% vs 23.6%; P = .367), frequency of persistent AD was significantly higher in children with multiple food sensitizations than in children with single food sensitization (33.3% vs 7.7%; P = .032).

“This study showed that the later allergic respiratory diseases in children with early-onset AD were associated with food sensitization regardless of early wheezing, and the persistence of AD was associated with multiple food sensitizations,” concluded the study author.

Reference

Özcan C. Atopic march in children with early-onset atopic dermatitis: A retrospective study. Rev Fr Allergol. Published online May 31, 2022. doi:10.1016/j.reval.2022.04.006