Food allergies are on the rise in the U.S. and other developed countries. In patients, food allergies appear as a variety of symptoms, ranging from mild skin inflammation to severe asthma. Recent studies suggest that contact between inflamed skin and food proteins may trigger food allergy development. A new study in the Journal of Clinical Investigation provides a link between skin sensitization, gastrointestinal inflammation, and food allergy. Using a mouse model, Steven Ziegler and colleagues at the Benaroya Research Institute found that skin exposure to a combination of food antigen (peanut or egg proteins) and the pro-inflammatory molecule thymic stromal lymphopoietin (TSLP) results in food allergy. Dermal application of TSLP and antigen resulted in a severe allergic reaction, including diarrhea and anaphylaxis, when mice ingested the antigen. Skin sensitization to antigen required TSLP. However, development of allergic responses in the gut required IL-25, a protein that regulates the intestinal immune response. Interestingly, mice given antigen orally prior to skin sensitization did not develop an allergic response. The results from this study provide a mouse model for skin-induced food allergy development that could be used to test potential therapeutic interventions.
