There has been a dramatic rise in the incidence of allergic disease, including eczema, among young children over the last few decades, but the reasons for this remain largely unknown.
While it is clear that genetic predisposition plays a big part in risk, the impact of allergic foods and the timing of food introduction remain less well understood.
" Food allergies contribute to about a third of moderate to severe eczema cases in children," pediatric allergist David Fleischer, MD, of National Jewish Medical and Research Center, tells WebMD.
Allergic foods, including dairy, eggs, nuts, and seafood have been linked to the development or trigger of eczema and other allergic diseases in some studies. But others suggest a protective benefit for some of these foods.
In their latest investigation, Alm and colleagues examined dietary and allergy data from almost 5,000 children enrolled in the Swedish health study.
By the time they reached age 6 months, 14% of the infants had developed eczema. By their first birthdays, 21% had previous or current eczema.
While early fish consumption was found to protect against eczema, it did not seem to matter if the fish the young children ate contained large amounts of omega-3 fatty acids.
It has been suggested that omega-3 is protective against allergic disease, but several recent studies have failed to show this, Alm says.
"There seems to be something special in fish that helps protect against eczema, but we can't say what that is," he says.