S. Gamboni, R. Nixon
Occupational Dermatology Research and Education Centre, Skin and Cancer Foundation Inc., Melbourne, Victoria, Australia Food allergies affect quality of life, can be fatal and are increasing in prevalence. “Food allergy” can be defi ned as “an adverse health effect arising from a specifi c immune response that occurs reproducibly on exposure to a given food”. Innate and adaptive immunity contribute to the development of food allergies, categorized into IgE-mediated, non-IgE mediated and cell mediated. Atopic dermatitis is a mixed IgE and cell-mediated reaction, with debate surrounding its relationship with food allergies. Traditional thinking stipulates that allergenic foods exacerbate atopic dermatitis, and avoidance relieves symptoms. Nevertheless, new insights, including the “outside-inside” hypothesis suggest that atopic dermatitis may actually be the primary insult, providing a defective epidermal barrier and weakening innate immunity. Over the last decade, dietary trends have delayed the introduction of potentially allergenic foods, such as cow’s milk, egg and peanut until a child is older, allowing the gastrointestinal tract to mature. Nevertheless, recent evidence suggests that predisposition to food allergies is related both to genetic predisposition and the timing of oral tolerance. Studies regarding the incidence of food allergy in different populations suggest that early exposure to potentially aller- genic foods may actually be protective, rather than detri- mental to the development of food allergies, contradicting previous advice, which may have contributed to the current epidemic.