Wednesday, January 21, 2015

A Wearable Patch for Allergy Desensitization

Food allergies can sometimes be so severe that they can lead to anaphylaxis, an allergic reaction in which a person's airway swells, blocking normal breathing. Some food allergies are so severe that exposure to even the tiniest amount can be life-threatening. Peanuts, eggs, milk, fish, shellfish, and wheat are among the most common food allergens.

One way to treat a person with a food allergy is to inject the allergen - at truly miniscule doses at first, and then when the patient's immune system begins to tolerate the allergen, slowly raising the dose. Another is to have the patient eat (ingest) miniscule amounts of the allergen. Both methods must be done under close supervision. If done properly, the patient gradually becomes "desensitized" to the allergen, that is, he/she becomes able to tolerate higher doses of the allergen. Although there is no guarantee that a person's food allergy will go completely away, desensitization can potentially reduce an allergic reaction enough that an allergic reaction is no longer life-threatening. The problem is that these desensitization methods (injection or ingestion) are somewhat risky - there's always the possibility that too big of an immune reaction (anaphylaxis) will be triggered by one of the treatment doses.

But now a French firm may have a better way. DBV Technologies has developed a plastic patch called Viaskin designed to deliver small doses of allergen slowly and directly into the skin. In the skin the allergen is taken up by cells of the lymphatic system and delivered directly to immune cells in lymph nodes, where the immune response takes place. Because the allergen never enters the bloodstream, the risk of anaphylaxis is reduced.

Initial clinical trials to test the safety and effectiveness of Viaskin using peanut allergen are encouraging. It is likely to be several years before Viaskin is available (more clinical trials are planned), but the company is so confident that it is already working on Viaskin products for milk allergies and for allergies to house dust and mites.

For more on this subject, go to a previous blog post titled "New Uses for Wearable Skin Patches."

No comments: