Lots of people who have eczema would like to know if allergic skin reactions to oatmeal-based emollients are truly a problem, as asserted by French investigators in a study that has garnered considerable attention.
Dr. Joseph F. Fowler Jr., said, "No," adding that the French study is fraught with shortcomings.
"I would have recommended against its publication, frankly," says Dr. Fowler, president of the North American Contact Dermatitis Group and a dermatologist at the University of Louisville (Ky.).
Joseph F. Fowler
The Bordeaux-based researchers reported that atopy patch test and skin prick test results to oat were positive in 15% and 19%, respectively, of 302 atopic children. Because the positive atopy patch test rate was higher in children less than 2 years old, the French investigators went on to recommend against using oat-containing topical skin products in infants with atopic dermatitis (Allergy 2007; 62:1,251-6), thereby stirring the ire of many experts.
Among the most notable problems with the French study is its reliance upon the atopy patch test, which enjoys some popularity in Europe but "is not the sort of thing we do routinely here in the U.S.," according to Dr. Fowler.
"It’s not a test we in America put much stock in," the dermatologist said. "Essentially it consists of doing a patch test with a piece of food. So if you want to do an atopy patch test to fish, you slap a piece of fish on the arm and see if anything happens there. That’s not terribly well controlled."
Also, the skin prick tests relied upon oat pollen rather than the colloidal oatmeal that’s the core ingredient in the oat-based emollients which enjoy widespread popularity among atopic dermatitis patients because of their well-documented anti-inflammatory, anti-irritant, and barrier-repair effects. It’s highly unlikely that the pollen contains the same proteins, polysaccharides, and other key constituents found in the oat grain.
Another critical problem with the French study is that the follow-up testing was unsupervised. Physicians didn’t actually evaluate the skin test results. They merely telephoned the families and asked if their children had reactions. It’s hard to know what to make of such findings, in Dr. Fowler’s view.
It’s worth noting that the Bordeaux study stands virtually alone in concluding that oats are an irritant or allergen in atopic individuals. As early as 14 years ago, a double-blind, randomized trial conducted in 43 atopic and 22 control infants found no urticarial or contact allergy reactions to an oat-based emollient (Am. J. Contact Dermat. 1997;8:207-9).
More recently, Spanish investigators conducted a randomized controlled study of an oat-based emollient in 173 atopic infants, concluding it was an effective steroid-sparing agent with no adverse effects (Dermatology 2007;214:61-7). And investigators at the University of Lyon (France) found no immediate or delayed allergic reactions to 42 days of repeat open patch and skin prick testing of an oat-containing cosmetic applied in maximal concentrations to 12 cereal-sensitized atopic adults (Dermatology 2009;218:327-33).
Large, long-term, population-based studies have identified several foods that uncommonly may trigger disease in atopic patients. These include eggs, peanuts, and milk. Oats don’t make the list, Dr. Fowler noted at the annual meeting of the American Academy of Dermatology in New Orleans.
Lastly, animal and human testing of the various commercially available oat-based skin care products hasn’t shown a signal of any problems. The most reasonable conclusion is that while anybody can be allergic to pretty much anything, oat-containing emollients are safe and effective in the vast majority of individuals, according to the dermatologist.
Dr. Fowler disclosed that he serves as a consultant to Johnson & Johnson, which markets the colloidal oatmeal-based Aveeno Eczema Therapy Moisturizing Cream.