The role of skin inflammation, barrier dysfunction, and oral tolerance in skin sensitization to gluten‐derived hydrolysates in a rat model

BACKGROUND: Adverse reactions to wheat‐containing skin care products have been linked to food allergy development. OBJECTIVES: To determine the role of skin barrier dysfunction and inflammation in sensitization to gluten‐derived hydrolysates via the skin in Brown Norway rats with and without oral tolerance to wheat. METHODS: Skin barrier defect was induced by mechanical disruption, and skin inflammation was induced by topical application of SLS or MC903. Unmodified, enzyme hydrolyzed, or acid hydrolyzed gluten products were applied to the skin three times per week for 5 weeks. Subsequently, rats were orally gavaged with unmodified gluten. RESULTS: Wheat‐naïve rats were readily sensitized to gluten hydrolysates via the skin. Skin barrier defect and skin inflammation had little effect on the skin sensitization and hydrolysate‐specific IgE levels. Oral administration of unmodified gluten promoted the production of unmodified gluten‐specific IgE in rats sensitized via the skin. Sensitization through intact skin, disrupted skin barrier, or inflamed skin was unable to break tolerance to unmodified gluten in rats on a wheat‐containing diet. CONCLUSIONS: Mechanical skin barrier disruption and skin inflammation play a limited role in experimental skin sensitization to gluten‐derived hydrolysates.