Can we prevent atopic dermatitis in susceptible patients?
When I was growing up it was quite the rare thing to hear that someone had a food allergy. I knew of a few children with eczema or asthma but these days one can’t help but notice the warnings everywhere at schools, camps etc to avoid bringing high risk allergens into close proximity with potentially susceptible children. As a Neonatologist I don’t profess to be an expert in the area of Atopic conditions but I do believe as others have suggested that society’s obsession with antibacterial soaps and not playing the sandbox so to speak has led to an over development of the allergic response of our immune system due to lack of stimulation on the “infection fighting side” during our infant and toddler years. As a Pediatric resident I recall treating many children in clinic for atopic conditions and certainly atopic dermatitis was extremely common and incredibly frustrating for parents not to mention the children.
In October of 2014, in the Journal of Allergy and Clinical Immunology Simpson et al reported a pilot study that could change the approach from treatment to prevention for many children if the results hold true in larger studies. The article abstract can be found here with the full article being free as well: http://1.usa.gov/1BR1typ
In this pilot randomized control trial emolients were used in the treatment arm once a day for the first 6 months of life and had to be started within three weeks of life. All of these children were deemed to be high risk by having a first degree relative with allergic disease. The emolients used in the US group were sunflower oil, cetaphil cream and aquafor ointment and were applied to all skin surface except for the head. The theory was that skin breaks in newborns and infants allow allergens to reach the subcutaneous tissue and elicit an immune response thus creating allergic skin disease no different than an exposure to peanuts, tree nuts, dust mites etc can later trigger the immune system to cause allergic rhinitis or food allergy (Fig 1 from quoted paper below). Previous observational studies had yielded some support to this theory so the RCT was an attempt to answer the question as to whether keeping the skin smooth without breaks could prevent atopic eczema from happening.
The study was not powered to show a difference but the results of the study make this comment irrelevant. If a study is underpowered and no difference is seen between two groups one cannot say with certainty if no effect is seen that there was in fact no effect. If a difference is seen in even the smallest study between two groups in the primary outcome this is in fact significant as it was in this study.
The study found that the treatment group incidence of atopic dermatitis at 6 months was 22% vs a 43% incidence in controls. This corresponds to a 50% reduction in risk with a number needed to treat to prevent 1 case of atopic dermatitis of about 6 but with wide confidence intervals due to the small size of the study (3-1138). This speaks to the issue with small studies. Although the results seem impressive at first when you examine how confident you are with the estimate of the benefit it may be much less than originally thought. One thing to note though is that about 20% of families did not adhere to the daily application of emolient so one has to wonder if the results would have been even more impressive had the use been more consistent.
That all being said, applying a cream or ointment once a day to keep your newborns’ skin smooth and free of cracks seems to me to be something that many parents (especially those of us who live in the North) do anyway. Atopic dermatitis is a terrible condition that causes a lot of stress and discomfort for children and their families. If applying a cream or ointment once a day for the first 6 months of life was able to achieve such dramatic results and avoid such a condition I see very little harm in trying. Of course a larger study will now need to be done to confirm the cited paper here but I think this is a potentially exciting simple treatment to prevent a terrible condition!
I am a fan of simple treatments and even more so of simple interventions to prevent children from ever experiencing a condition at all. Might early use of emolients be one of these strategies?