Introduction
Atopic dermatitis (AD), also known as eczema, is a chronic inflammatory
skin condition, characterized by dry, red and itchy skin1,2. AD usually begins in infancy and affects up to
one fifth of children 3,4. The pathogenesis includes
impaired skin barrier function as a significant pathomechanism, along
with cutaneous immune dysregulation and microbial disturbances5. Supporting this is the consistent evidence that
loss-of-function mutations in the filaggrin gene (FLG ), resulting
in measurable skin barrier defects, plays a central role in the
inherited risk of AD 6.
Daily emollient use is a cornerstone of AD management7. Recently, the spotlight has been on the potential
role of emollients in infancy in preventing AD. Prompting this were
findings from two small randomised control trials (RCTs) reporting that
daily emollient application from birth until 6-8 months reduced AD risk
by up to 50% 8,9. Unexpectedly, these findings were
not replicated in two much larger scale studies 10,11.
The Barrier Enhancement for Eczema Prevention (BEEP) trial recruited
1394 high-risk infants and randomised them to either daily emollient
application for the first year or to standard skin care advice alone10. No evidence of a protective effect of emollient
use against AD at 1 or 2 years was found. The Preventing Atopic
Dermatitis and Allergies in Childhood (PreventADALL) study involved
baths for 5-10 minutes with added emulsified oil and cream applied to
the face after the bath on at least 4 days per week from 2 weeks to 8
months and reported no effect on AD prevalence when assessed 4 months
later at 12 months. Another RCT where emollient was applied daily to the
face only from 0-6 months also reported no effect 12.
The data from these three RCTs largely contributed to the conclusion of
a recent meta-analysis that skin care interventions probably do not
influence AD development 13. This meta-analysis used
an individual participant data approach, excluding studies only
providing aggregate data. In contrast, another meta-analysis including
more studies found a beneficial effect of emollients in high-risk
infants [RR (95% CI: 0.59 (0.43, 0.81)], but only when used up to
the point of AD assessment and not when there was an interval between
the treatment and the assessment 14.
The BEEP and PreventADALL studies used petroleum and paraffin-based
emollient formulations, 10,11 and while Dissanayake et
al. used a more complex ceramide-based emollient, the latter study’s
intervention involved application to the face only 12.
Data from a small pilot study suggest that emollients with ingredients
specifically designed to repair the skin barrier warrant further
investigation 15. Interventions in BEEP and
PreventADALL began at a median age of 11 days and from 2 weeks and
continued for 12 and 8 months, respectively 10,11.
Daily emollient application for an extended period in infancy places
considerable additional demands on new parents and may not be feasible
at a population level, especially if specialized and more expensive
emollients are advised. This may be reflected in the low adherence of
27% to the intervention in PreventADALL 11. We have
shown that trans-epidermal water loss (TEWL) increased from birth to 2
months but stabilised thereafter 16 suggesting a
shorter intervention period, beginning as soon as possible after birth
may represent a more feasible intervention, while targeting a critical
period of skin maturation.
This study aimed to investigate if daily emollient use from birth to 2
months can reduce the incidence of AD in high risk infants.