Eczema and food allergies typically start in early childhood, and eczema sufferers usually also suffer from food allergies and vice versa. These conditions are linked to an impaired skin barrier in early infancy but so far, the effectiveness of attempts to prevent or reverse this shortly after birth has been unclear.
Researchers from several universities in the UK, Europe, Australia and Japan therefore sought to find out if skin care interventions on infants would help to prevent eczema or food allergies. Through a review of 33 randomised clinical trials (RCTs) involving a total of 25,827 study subjects, they assessed the impact of skin care interventions (such as emollients) for the primary prevention of eczema and food allergy in infants.
As a secondary objective, they also identified the features of the study populations, such as age, hereditary risk and adherence to interventions associated with “the greatest treatment benefit or harm” for both eczema and food allergies.
Skin in the game
The majority of the studies included in the review had been conducted at children’s hospitals, with 25 of them conducted on newborns up to the age of three weeks. These infants were randomised to receive either skin care intervention or standard infant skin care, while in eight of the studies, the participants were infants at high risk of developing food allergies or eczema.
The researchers then reported that, based on evidence from seven RCTs involving 3075 participants, skin care interventions during infancy probably did not alter the risk of eczema by one to three years of age. At the same time, nine of the RCTs (3,349 participants) found that skin care interventions during infancy did not change the time it took for eczema to occur in children.
In fact, one RCT of 976 study subjects reported that skin care interventions during the infancy might even increase the risk of food allergies by one to three years of age, though three RCTs (1,794 study subjects) found that such interventions might not alter the risk of allergic sensitisation to food allergens by the same age.
The review further noted that, according to one RCT of 1,171 participants, skin care interventions during the infant stage might “slightly increase the risk of parent reports to a common food allergen” at two years of age. However, as this was observed only in the case of cow milk consumption, the review acknowledged that the information might be unreliable due to the over-reporting of milk allergies in infants.
In addition, based on evidence in six of the RCTs involving 2,728 study subjects, the review stated that skin care interventions during the infancy period “probably increase risk of skin infection over the intervention period”. Furthermore, according to the results of four of the RCTs (343 study subjects), such interventions might increase the risk of stinging or allergic reactions to moisturisers.
Other factors and future indications
Based on pre-planned sub-group analyses, the researchers observed that the impact of skin care interventions during the infancy stage were “not influenced by age, duration of intervention, hereditary risk, or classification of intervention type” for the risk of developing eczema.
However, they were unable to evaluate any possible effects of the aforementioned factors on food allergy risk. Additionally, the reviewed RCTs provided insufficient evidence to show whether adhering to skin care interventions affected the link between these interventions and the development of food allergies or eczema.
The researchers added that the evidence gleaned from the review was low to moderate in certainty, saying that skin care interventions during the first year of life in healthy infants were unlikely to help in preventing eczema and could even increase food allergy risk.
They further concluded that more research was required to “understand whether different approaches to infant skin care might prevent eczema or food allergy”.