A study by Dr Leung showed that children with food allergy related eczema differ from those eczema patients without food allergy by changes in uninvolved skin. Those with food allergy were shown to have increased water loss, increased Staph colonization, and changes consistent with a immature skin barrier (as determined by gene expression studies).
The study was done by sampling the upper layer of the skin by removing cells with scotch tape. The food allergy involved was peanut allergy, in those considered food allergic. It should be noted that peanuts are far more active as lectins than other food allergens, that this study was done in a dry elevated city of Denver, and that it may or may not be applicable to all eczema patients with food sensitivities. The implication of the study is that a defective skin barrier plays a role in food allergy related eczema. We are still far from being certain that this is a as good a way to determine if food allergies are involved in an eczema patient’s outbreaks, compared to history of flares. Also, the tests used are mostly not clinically available. Nevertheless, it is an important advance, and supports the notion that a sub-population of a topic dermatitis patients do have food allergies related to their condition.
Alan M Dattner, MD