AUSTIN – The
Dr. Jennifer J. Schoch
“While more time in the NICU is associated with a lesser risk of developing atopic dermatitis, we certainly do not want to keep infants in the NICU longer in order to lower their risk of atopic dermatitis,” the study’s first author, Jennifer J. Schoch, MD, said in an interview prior to the annual meeting of the Society for Pediatric Dermatology. “Instead, we need to work on understanding the mechanisms behind this relationship. For example, are there certain exposures in the NICU that influence the cutaneous immunity to ultimately reduce the risk of atopic dermatitis?”
According to Dr. Schoch, a pediatric dermatologist at the University of Florida, Gainesville, the medical literature has been conflicted regarding the relationship between prematurity and eczema. A recent meta-analysis of 18 studies found an association between very preterm birth and a decreased risk of eczema, yet the risk became insignificant among children born moderately preterm (J Am Acad Dermatol. 2018;78[6]:1142-8). However, the factors contributing to this relationship are not well understood.
In an effort to explore the infant, maternal, and environmental factors of infants who developed AD, compared with infants who did not, Dr. Schoch and colleagues evaluated infants who were born at University of Florida Health from June 1, 2011, to April 30, 2017; had at least two well-child visits; and had at least one visit at 300 days old or later. The researchers included 4,016 mother-infant dyads in the study. Atopic dermatitis was diagnosed in 26.5% of the infants. Factors significantly associated with the incidence of AD were delivery mode (P = .0127), NICU stay (P = .0001), gestational age (P = .0006), and birth weight (P = .0020). Specifically, infants had a higher risk of developing AD if they were delivered vaginally, did not stay in the NICU, had a higher gestational age, or had a higher birth weight. Extremely preterm (less than 28 weeks’ gestation) and very preterm (28 to less than 32 weeks’ gestation) infants had the lowest rates of AD, at 10.9% and 19%, respectively.
When the researchers adjusted for other variables to their model, only length of stay in the NICU was related to the development of AD. Specifically, infants who spent more time in the NICU had a lower risk of developing atopic dermatitis (P = .0039).
“We were surprised to find that the length of stay in the neonatal intensive care unit was the strongest protective factor against the future development of eczema,” Dr. Schoch said. “Instead of this relationship being mediated by gestational age or birth weight, it was how much time the infants spent in the NICU that seemed to ‘protect’ from future eczema.”
She acknowledged certain limitations of the study, including its retrospective design with data gathered from electronic medical records. Also, “diagnosis was determined by ICD-9 or ICD-10 code, and not confirmed by dermatologists,” she said.
In their abstract, the researchers wrote that the finding highlights “the importance of early life interactions between the microbiome, developing cutaneous immunity, and the evolving skin barrier of the preterm infant. The skin microbiome of premature infants differs from full-term infants, in that the premature infant cutaneous microbiome is dominated by Staphylococcus species” (Microbiome. 2018;6[1]:98). They added that “the early presence of Staphylococcus on the skin may confer protection.”
Dr. Schoch reported having no relevant financial disclosures.
SOURCE: Schoch J et al. SPD 2019, Poster 2.