It was a while ago now, but not long after I wrote a post called Are Oats Good for Eczema? a reader wrote to me and pointed out that, if you have nickel allergy, oats can be a problem.
As well as avoiding physical contact with nickel — which is found in razors and shavers, jewellery, coins, zips, jeans studs, electrical equipment, among other places — some who are very sensitive to nickel exposure through the skin also react to nickel exposure in the diet. Rather than the localised symptoms that comes from physical contact with nickel, dietary exposure can cause symptoms anywhere on the body’s skin. This is sometimes referred to as systemic nickel allergy syndrome (SNAS), and gastrointestinal and neurological symptoms are also common. It is rare, but can be severe.
Although the nickel content of food is often dependent on the soil its grown in, some foods are particularly high in nickel. These include oats (and other grains), chocolate, most legumes, tinned fruit, tinned tomatoes, tinned fish and tea, especially green. Those with ongoing symptoms and an allergy to nickel confirmed by patch test are sometimes advised to try a low-nickel diet, if all other preventative measures have been taken.
But this of course begs the question: can oats in cosmetics products, often recommended for those with eczema and dermatitis, make things worse, due to the potential high nickel content?
This deserves serious consideration, because nickel allergy is so common (up to 1 in 6 women may have it) and because oats are such a popular ingredient in therapeutic skin creams, which women may turn to if they detect mild eczema on their bodies.
Anecdotally, there are some reports that nickel-allergic and oat-tolerant people have reacted to oat-containing creams — but could these be highly sensitive individuals, and therefore extreme cases?
The nickel content of oats varies, but in Canadian oats can be as high as 3ppm (3 parts per million) nickel. Research suggests only few people with nickel allergy react to 10ppm or lower. And, of course, nobody applies ‘neat’ oats to their skin, so the nickel content of an oat-based skin cream or bath soak should, in theory, be considerably less than that.
Study-wise, the picture is not clear.
One study found highly sensitised nickel allergy patients exposed to 0.5ppm on inflamed skin reacted.
But another found no patients with nickel allergy reacted under 100ppm, although there were some ‘follicular reactions’ at much lower levels.
Those with allergic contact dermatitis are often sensitive to more than just one contact allergen. Some of the major culprits are fragrances (fragrance-free skincare and household detergents can prove very useful), and preservatives such as methylisothiazolinone and methylchloroisothiazolinone. It is worth undergoing patch testing if you don’t have the specific answers you need and you’re continuing to react to something uncertain.
And if you’re happily using oat-containing brands such as Aveeno with no problems, or even with obvious benefits? Then carry on: there’s no reason to stop.
But if something’s not right, consider checking your products for ‘avena sativa’ and other possible sensitisers and experimenting with even gentler products.
You may find this article — Allergen Free Cosmetics — has some handy recommendations.