Aggravation of Food Allergy by Skin Sensitization via Systemic Th2 Enhancement

Recently, the relationship between antigen contact via skin (skin sensitization) and the development of food allergies has gained increasing attention. However, few studies have examined the effects of skin sensitization on healthy skin.

To examine the effect of sensitization in healthy skin on IgE and cytokine production during food allergy development.

The effect of skin sensitization on food allergy was evaluated using DO11.10 mice whose T cells express ovalbumin (OVA)-specific T-cell receptors. OVA was applied to the back skin of mice dehaired by various methods, and then food allergy was induced by providing them with an OVA-containing diet. OVA-specific IgE production in the sera and decreases in body temperature due to anaphylactic reaction were measured as indicators of food allergy. In addition, IL-4 production and proliferation of splenocytes were measured in mice with food allergy after skin sensitization.

Skin sensitization in healthy skin increased IgE production and exacerbated anaphylactic symptoms induced by ingesting the antigen. Moreover, skin sensitization enhanced IL-4 production from splenocytes during the onset of food allergy. In contrast, oral tolerance was induced even after establishing skin sensitization.

Skin sensitization temporarily exacerbated food allergy by enhancing systemic Th2 responses. These findings will help identify the mechanisms involved in food allergy and help develop treatments.