Allergies in eczema : review article

Abstract

The prevalence of both food allergies and eczema has increased over the past two decades, and there is a close association between the two, particularly in infants and young children. A significant proportion (30-40%) of children with eczema will have a coexisting food allergy, mostly IgE-mediated. In approximately half of those patients who react to food, there will be a flare-up of eczema. In patients with moderate to severe eczema, or if there is a high suspicion of a food allergy, food allergies should be actively excluded. History, skin-prick tests and specific IgE are sensitive but not specific in eczema sufferers, hence the crucial role for food challenges to confirm or refute allergies. If there is a high suspicion of foods exacerbating eczema but no evidence of immediate reactions, elimination-rechallenge diets should be used. Blanket elimination diets for eczema are ineffective and potentially harmful. Elimination diets should target only those foods to which the child is proven to be allergic, and should always be combined with atopic skin care. Eczema is an epithelial barrier disease, and dysregulation of epithelial function may lead to both food and aeroallergens entering through the impaired barrier. Thus eczema itself may predispose the patient to food sensitisation/allergies and also propagation of the allergic march.