Infants at high risk for atopic dermatitis who used emollients daily through their first 2 months of life experienced less disease in their first year than high-risk infants who did not use emollients, according to study results. The high adherence rates among participants indicate that this emollient use represents a feasible and family friendly strategy for AD prevention as well, Carol Ní Chaoimh, BSc, PhD, a postdoctoral researcher at University College Cork and project manager at the INFANT research center at University College Cork, both in Cork, Ireland, and colleagues wrote in the study, published in Allergy.
The randomized controlled clinical trial involved 321 infants recruited at Cork University Maternity Hospital with at least one parent with a self-reported history of AD, asthma or allergic rhinitis, indicating that the infants were at high risk for AD as well. Within 4 days of birth, researchers randomly assigned 161 of these infants to a group that would apply Aveeno Dermexa Fast & Long-Lasting Balm (Johnson & Johnson) twice a day to their whole body for the first 8 weeks of life, and 160 to a control group that would follow standard skin care advice given at the hospital. Caregivers and infants attended study visits throughout the next 12 months, and caregivers completed questionnaires and maintained study diaries.
Most of the participants in the treatment group applied emollients once or twice daily at 2 weeks (89%; 63.3%) 4 weeks (91.7%; 69.2%) and 8 weeks (86.6%; 73.1%), with 68.2% of the control group reporting emollient use less than four times a week at all three time points. None of the families sought emergency medical assessments due to the intervention. Also, parent-reported skin infections occurred in 5% of the treatment group and 5.7% of the control group during the 8-week intervention period. Cumulative incidence rates of AD at 12 months, which served as the primary outcome, were 32.8% for the treatment group and 46.4% for the control group (RR = 0.707; 95% CI, 0.516-0.965). These rates at 6 months, which was one of the secondary outcomes, included 18.3% for the treatment group and 36.4% for the control group (RR = 0.503; 95% CI, 0.325-0.779).
Overall, a time-to-event survival analysis showed the treatment group remained AD free for a longer period during the first 12 months than the control group (P = .016). The study cohort also included 253 patients who provided filaggrin gene (FLG) genotype data, including 44 (17.4%) with loss-of-function FLG mutations, which lead to skin barrier defects and contribute to the inherited risk for AD. The effect size associated with the intervention was greater at 6 months among those with FLG mutation (RR = 0.337; 95% CI, 0.13-0.873) than those with wild-type FLG (RR = 0.527; 95% CI, 0.318-0.871), with a nonsignificant trend showing the same association at 12 months (mutated, RR = 0.524; 95% CI, 0.265-1.036; wild type, RR = 0.722; 95% CI, 0.502-1.038).
The researchers noted that the mechanisms behind the reduced incidence of AD among the patients who used daily emollients is unclear, although they added that an ongoing analysis of microbiome diversity and inflammatory markers in a subgroup of these patients may provide additional information. Additionally, the researchers called for studies that would examine the use of more complex emollients that would enhance the skin barrier in various populations and ethnicities. These studies should identify an effective and acceptable treatment window for patients and caregivers as well, the researchers continued.
