Atopic dermatitis food allergens

A murine model of food-induced atopic dermatitis confirmed the important role of specific T cells in eczema here, C3H/HeJ mice were orally sensitized to cow s milk or peanut and thereafter exposed to the allergen. An eczematous eruption developed in approximately one third of mice after low-grade exposure to milk or peanut proteins. Histological examination of lesional skin revealed spongiosis and a cellular infiltrate mainly consisting of CD4-I- lymphocytes. 

Patients sensitized to pollen allergens often develop an IgE response to cross-reactive food allergens. Birch pollen-related food may lead to an exacerbation of eczema in a subpopulation of patients with atopic dermatitis and sensitization to birch pollen allergens. A birch pollen-specific T-cell response could be detected in lesional skin of these responding patients. T-cell cross-reactivity between Bet v 1 and related food allergens can occur independently of IgE cross-reactivity in vitro and in vivo. This has been shown in atopic dermatitis patients who developed late eczematous skin reactions to cooked food which was shown to elicit T-cell but not IgE-mediated responses [11]. 

Burks, A.W., Williams, L.W., Connaughton, C., Cockrell, G., O Brien, T.J., Helm, R.M. 1992. Allergenicity of peanut and soybean extracts altered by chemical or thermal denatur-ation in patients with atopic dermatitis and positive food challenges. J Allergy Clin Immunol 90 889-897. 

The duality of Thl and Th2 T-helper cells that exists in murine animals probably also exists in humans (14). It has been postulated that IL-4 enhancement promotes the development of IgE-mediated hypersensitivity disorders such as food allergy, while the combination of defective INF-y with enhanced IL-4 production promotes inflammatory atopic disorders such as atopic dermatitis and asthma. IgE irmnunoregulation suggests that the magnitude of the IgE response to persistent allergens depend upon this balance between T-helper cells and their cytokine production. However, environmental and other as yet unidentified factors also contribute to the allergic state of the predisposed individual. 

McFadden, J., White, J.M.L., Basketter, D., and Kimber, I. 2008. Reduced allergy rates in atopic eczema to contact allergens used in both skin products and foods Atopy and the hapten-atopy hypothesis. Contact Dermatitis 58(3) 156-158. 

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