Historically, many have focused on the idea that food allergies drive atopic dermatitis. It seems to make good sense that things we eat can greatly influence the skin. Accordingly, many patients undergo very strict diets, some successful to be sure, but many without much improvement. Sadly, those who do not improve with dietary changes rarely get much attention on the internet and often feel isolated and left behind.
Excitingly, a new body of research is accumulating that at least some of the time, we have had this relationship backwards. The problem of “leaky skin” may be just as important as “leaky gut”. The skin is the primary barrier to toxins, bacteria, and allergens of all kinds. Have you ever wondered how an infant who has never eaten peanuts or tree nuts can be sensitized to them? Perhaps it is because these proteins are all over our environment and having a weak skin barrier may allow them to enter into the skin and actually cause the allergy. In fact, there have been studies that show when the skin barrier is damaged (as it is in eczema) and foods are applied to the skin, a true food allergy can develop!
Studies at Oregon Health Science University take this a step further: they suggest that by protecting the barrier function of the skin using moisturizers, we can possibly delay or even prevent eczema and food allergies! This is extremely important because it may mean that we are not simply treating the symptoms, but that by protecting their skin barrier function we are possibly protecting them from developing worsening eczema, food allergies, and other allergies in the long run. In other words, we are treating the actual root of the problem: leaky skin.
Avoiding triggers such as allergens and irritants is critical as well, but without a good skin barrier, it can become an impossible task. It is akin, perhaps, to a house that is on fire. Even though we’d like to understand what caused the fire in the first place, once the fire is burning, it is critical to put it out and protect the rest of the home. It might not look pretty, but you need to keep animals, bugs, and intruders out of the home, while protecting all that is precious to you on the inside. Thus, we often rely on anti-inflammatory agents to put out that initial fire, but we must also fireproof the structure for the future. Thus, we try to lean heavily on protecting and rebuilding the skin barrier with moisturizers and natural oils.
Food allergies and eczema remain significant challenges: they truly are multifactorial and do not have one easy answer, but the are deeply related, one way or another.