Tuesday, April 5, 2016
Food Allergen Immunotherapy: Current Status and Prospects for the Future
Food allergies are a growing problem, with one in twelve children having at least one allergy, commonly peanut, eggs, milk, wheat, soy, and shellfish. Despite the enormity of this problem, allergists have so far been unable to provide any pro-active treatments, apart from advising patients to avoid those foods and to keep an epi-pen nearby in case of anaphylaxis. But there’s now some hope. In this month’s issue of JACI, Dr. Wood surveys a slew of new therapies that aim to modify the immune system so that children can be desensitized to the foods they are allergic to (J Allergy Clin Immunol 2016; 137(4): 973-982).
The classic approach of desensitizing patients to environmental allergens – like pollens or dander - through shots, has been tried before with food allergies. Although this approach was somewhat successful for a few children, the risks were far too high and it has largely been avoided. Recently, oral immunotherapy – that is, ingesting really small amounts of the food, and increasing that dose of food, over the course of weeks – is coming into fashion. Early research results suggest that this approach is effective but it is still far from coming to the clinic.
More recently, sublingual immunotherapy has been tried: small amounts of the food is allowed to sit under the tongue for two minutes and then swallowed. This amount is slowly increased to help children become less sensitive. Compared to oral immunotherapy, it’s safer, but it also seems to be less effective.
This has led people to think of other ways to desensitize allergic children to their foods. One way is percutaneous immunotherapy, in which a patch with the food allergen is applied to the skin. While research is still early, it looks promising – although a lot of side effects like local redness or eczema at the site of the patch have been reported.