Atopic dermatitis is associated with shorter stature, increased body mass index (BMI), and lower weight in early childhood, although the associations with height and BMI are attenuated as the children age, according to study data published in JAMA Dermatology.
Researchers used data from the prospective, longitudinal TARGet Kids! (The Applied Research Group for Kids) study, which enrolls children from general pediatric and family practices in Toronto, Canada. Participants have been enrolled before age 6 years since June 2008 and are followed up into adolescence.
The primary outcomes were height (length-for-age z scores; z-height) and BMI (BMI z scores; z-BMI).
A total of 10,611 children with 32,036 physician visits were included, with each child having a median (interquartile range [IQR]) of 2 (1-4) visits. The participants had a mean (SD) age at entry of 23 (20) months, and 5070 (47.8%) were female. The children were followed up for a median (range) of 28.5 (0.0-158.0) months.
Among the cohort, 8.9% of children had parent-reported atopic dermatitis at baseline, and 17.3% of children had atopic dermatitis during the follow-up, including baseline.
Atopic dermatitis was associated with lower mean z-height (−0.13; 95% CI, −0.17 to −0.09; P < .001) vs children without atopic dermatitis after adjustment for covariates. Strong evidence of an interaction between atopic dermatitis and age was observed (P = .002).
The linear mixed effects model estimated that children with atopic dermatitis were about 0.5 cm shorter at age 2 years and 0.6 cm shorter at age 5 years on average than children without atopic dermatitis based on growth tables from the World Health Organization and after adjustment for covariates. The differences in height were attenuated as the children aged and were similar by age 14 years.
Atopic dermatitis was also associated with higher mean z-BMI (0.05; 95% CI, 0.01 to 0.09; P = .008) vs children without atopic dermatitis after adjustment for covariates.
In addition, atopic dermatitis was associated with lower mean z-weight (−0.07; 95% CI, −0.10 to −0.04; P < .001), with no evidence of an interaction between atopic dermatitis and age at a 5% level of significance (P = .08).
The findings are limited owing to use of parental report to assess atopic dermatitis. Also, the study authors did not have data regarding the severity and clinical activity of atopic dermatitis, and residual confounding from unmeasured covariates, including paternal height and weight, is possible. Furthermore, potential mediators such as sleep and dietary patterns were not assessed.
“To our knowledge, ours is the largest longitudinal study to date and supports the hypothesis that while atopic dermatitis may be associated with shorter stature in early childhood, this association does not persist,” stated the investigators. “This is reassuring about long-term outcomes for young children with atopic dermatitis and short stature.”
Nicholas MN, Keown-Stoneman CDG, Maguire JL, Drucker AM. Association between atopic dermatitis and height, body mass index, and weight in children. JAMA Dermatol. Published online November 17, 2021. doi: 10.1001/jamadermatol.2021.4529