Sublingual Immunotherapy for Milk Allergy
Researched and written by Eric Byrtus, a Grade 12 student from Edmonton, AB
Vaccines work great for diseases, so why not allergies? Research around the world has confirmed the effectiveness of sublingual (oral) immunotherapy in treating milk and certain other food allergies. Immunotherapy, the desensitization to a certain allergen, is one of the oldest approaches for managing allergic diseases, having first been performed for grass pollen ‘hay fever’ over 100 years ago. Rather than traditional treatment of antihistamines and corticosteroids, which only treat the symptoms, immunotherapy has the potential to modify the natural course of the allergic disease. However, it has not been commonly used to treat food allergies, given the high risk of anaphylaxis. There are currently two types of immunotherapy: subcutaneous and sublingual. Subcutaneous involves numerous injections (“allergy shots”) just below the skin, while sublingual involves small drops (“allergy drops”) or tablets being placed under the tongue.
Unlike subcutaneous immunotherapy, used to treat inhalant allergens such as dust, pollen and mould, the new sublingual immunotherapy, currently being tested for use in treating food allergies, is largely administered at home by the patient or caregiver. Other benefits to using the sublingual method include fewer side effects, significantly lower risk of anaphylaxis, lower cost, and noticeable improvement in just a few months. Sublingual immunotherapy has also already shown tremendous promise in treating the same types of allergies as the subcutaneous method.
Treatment for food allergies will usually be conducted once daily, very gradually increasing the dose to a pre-determined target which would hopefully induce a state of tolerance, potentially normalizing the patient’s diet. At the least, this should offer protection against anaphylaxis with small accidental exposures. With all of the advantages over subcutaneous immunotherapy, and especially over traditional treatments, it is hard to believe that sublingual immunotherapy is not being used more frequently. In fact, allergy drops have been used around the world for more than 60 years, and numerous studies validate both their safety and effectiveness. The World Health Organization (WHO) has endorsed sublingual immunotherapy as a viable alternative to injection therapy. The Cochrane Collaboration, the world’s most-trusted international organization dedicated to reviewing healthcare treatments, recently concluded that allergy drop immunotherapy significantly reduces allergy symptoms and the use of allergy medications.
This method of treatment is gaining acceptance throughout the world, and is increasingly being studied for food allergies, most commonly with milk, eggs, peanuts, and hazlenuts. Based on this very exciting research, pediatric allergists in Edmonton have begun offering oral milk desensitization for selected patients, and anticipate offering this for egg and peanut allergies in the foreseeable future. Drs. Carr, Lidman, and Vander Leek are all optimistic that this novel approach to food allergy will prove life-altering for patients with persistent hypersensitivity.
Editor’s note: Sublingual immunotherapy described in this article (also called sublingual swallow immunotherapy) must be distinguished from an unproven, controversial technique used decades ago and, to a lesser degree, now, called sublingual provocative testing, neutralization and sublingual desensitization.
from Allergy & Asthma News, Issue 2 2008