1 of 2 | The role played by diet in the skin disease eczema has long been the subject of medical debate, and this week U.S. dermatologists will hear evidence that eliminating specific foods doesn't make much difference in preventing flare-ups. Photo by John Ciccarelli/U.S. Air Force
March 7 (UPI) -- Contrary to commonly held beliefs, current research shows that cutting out certain foods makes little difference in controlling the skin disease eczema, a renowned U.S. dermatologist said Friday.
The latest probes into the complex links between diet, food allergies and eczema -- also known as atopic dermatitis -- reveal eczema may be better controlled or even prevented by building up tolerances to allergenic foods at an early age, according to Dr. Peter Lio, a dermatology and pediatrics professor at Northwestern University's Feinberg School of Medicine in Chicago.
Lio is a keynote speaker at this year's American Academy of Dermatology annual meeting, which began Friday in Orlando. During the gathering he said he will assemble and present the latest thinking on the long-controversial subject of how foodstuffs and food allergies interact with atopic dermatitis.
Eczema is a chronic disease that usually begins in childhood in which the skin becomes extremely itchy. Scratching it can lead to further redness, swelling, cracking, "weeping" clear fluid, crusting and scaling, according to the National Institutes of Health.
Many sufferers have flare-ups in which the symptoms worsen, followed by periods when the skin improves or clears up entirely, called remissions.
What causes eczema remains unknown, although links have been found connecting it to genetics, the immune system and the environment. But just how diet and food allergies interact with eczema remains a mystery after nearly two centuries of medical debate.
While younger children with atopic dermatitis typically exhibit sensitivity to food items like peanuts, milk or eggs, strict "elimination diets" have not proven to be particularly effective at controlling the disease in a vast majority of cases.
Among Lio's key points at the Orlando conference is that recent studies generally refute long-held "common sense" beliefs held by many eczema sufferers that their conditions must somehow be related to what they eat.
"Many patients and families start the visit by explaining that they are convinced that food must be the 'root cause' of their eczema. It would be fantastic -- and easy -- if it were just food causing the eczema. But, in my experience, and more importantly, when carefully reviewing the literature, we find that this very rarely the case," he told UPI in emailed comments.
And yet, food allergies do indeed appear be associated with eczema -- but maybe just not in the way commonly believed.
There are very often "real, dangerous food allergies associated with atopic dermatitis," Lio said. "Things like peanut allergy, shellfish allergy, and milk allergy are all much more common for patients with eczema and can even be life threatening. So, eczema and food allergy are clearly related, it just seems that the arrow of causality was pointing in the wrong direction."
Rather than diet causing a reaction, new research suggests it might actually be allergens "leaking" through damaged skin and into the body that triggers eczema and compromises the immune system.
And, if a "leaky" skin barrier is the culprit, then it may be wiser for parents to introduce children to peanuts and other potentially allergenic foods at an early age to help "teach" their immune systems to tolerate them, Lio said.
"The guidance around when to eat allergic foods has flipped 180 degrees: where there used to be guidance asking patients and families to hold off on allergic foods such as peanuts, we have now seen the guidelines encourage eating those foods as early as safely possible," he said. "This has been incredibly exciting to see."
In fact, last year a study supported by the National Institutes of Health's National Institute of Allergy and Infectious Diseases found that feeding children peanut products regularly from infancy to age 5 reduced the rate of peanut allergy in adolescence by 71%, even when the children ate or avoided peanut products as desired for many years.
Those results came nine years after the landmark Learning Early About Peanut Allergy, or LEAP, study determined that the introduction of peanut at age 4 to 11 months in infants with severe eczema reduced the risk of peanut allergy by more than 80% compared with peanut avoidance.
The findings "should reinforce parents' and caregivers' confidence that feeding their young children peanut products beginning in infancy according to established guidelines can provide lasting protection from peanut allergy," NIAID Director Jeanne Marrazzo said in May.
The mounting evidence that many, if not most, cases of peanut allergies could be prevented indeed represents a "shift in approach [that] could have lifelong benefits for those infants and their families as well as begin to curb the growing epidemic of food allergy in the U.S. and other parts of the world," said Sung Poblete, CEO of Food Allergy Research & Education, a nonprofit group dedicated to food allergy awareness, research, education and advocacy.
Eczema, he told UPI, is "more than a skin condition" in that it can serve as an "early warning sign of food allergy, can help identify high-risk infants who may benefit from early, frequent exposure to peanut-containing foods, as demonstrated by the LEAP study."
Evidence shows that as many as 81% of peanut allergy cases can be prevented, Poblete noted, adding, "It is more important than ever that parents, primary care providers, pediatricians, and dermatologists understand the potential implications of eczema so that they can guide families toward preventive care where appropriate."
FARE this month released a public service announcement called Eat Early, Eat Often that introduces new parents to the recommendations that came from the LEAP study, urging that a "few spoonfuls of infant-safe peanut foods today could mean a lifetime of worry-free eating tomorrow."
