Immunotherapy for Food Allergies

Immunotherapy for food allergies

The concept of food triggered hypersensitivity reactions was pioneered in the 1930’s by Dr.
Arthur Coca. At the same time period Dr. Albert Rowe developed elimination diets to diagnose and treat food allergy.

Food allergy is a serious and growing problem. Although the current standard of care for
patients with food allergies is based on avoidance of the trigger, increased understanding
of the mechanisms involved in oral tolerance has shifted focus of treatment and prevention
toward inducing tolerance.

Food allergy affects 6% of children younger than 3 years of age and approximately 4% of
adults in the United States. A recent report from the Centers for Disease Control confirmed
these figures, and also identified an 18% increase in food allergies amongst the United
States children over the past 10 years Food-induced anaphylaxis is the most common cause of anaphylaxis treated in hospital emergency departments .

At present, the standard of care for food allergy includes strict avoidance of food allergens and ready access to self-injectable epinephrine. The difficulty in avoiding food allergens and the potential for sudden and life-threatening reactions can diminish health-related quality of life for patients and their families.  Thus, novel treatment strategies for food allergy are needed. The concept of food allergy and foods causing medical illness is the basis of much controversy and heated emotional responses on both sides of the argument. Most articles in the conventional medical literature state that true food allergy is rare and not usually a factor in the general medical evaluation of a patient’s symptoms. Because numerous offending foods may produce a multitude of symptoms in many different organ systems, most traditional physicians have difficulty understanding and accepting this concept.

Traditional immunotherapy, via allergy shots, is a century-old technique most commonly used to treat inhaled allergens — such as cat dander and pollen — and it’s also standard
treatment for bee sting allergy. Sublingual immunotherapy is taken as drops or tablets,
placed under the tongue 3 or more times/week, containing a specific allergen which interacts with the immune system to decrease allergic sensitivity. Commonly the allergen is taken once a day. Because sublingual drops are used several times per week, it is necessary to take them at home. This is in contrast to injection therapy, which should always be taken in a medically supervised setting due to the know risks of anaphylaxis (about 1/2000) and death (about 1/2,500,000). In a recent review of ALL studies on SLIT by the American Academy of Allergy, Asthma and Immunology published in Journal of Allergy and Clinical Immunology, 2007: 6: 1466-1468, 35% of studies resulted in significant reductions in medications and symptom scores but 38% of studies found no significant benefit from SLIT. When SLIT did work, it was typically less effective than with conventional subcutaneous injection immunotherapy and sometimes SLIT took two years to show significant clinical benefit.

Allergy injection therapy has been administered as an effective treatment for over 100
years, and its clinical effectiveness in treating nasal allergy, allergic asthma and stinging insect (venom) allergy is well documented. SLIT is not considered more effective than AIT, but because SLIT is much less likely to cause adverse reactions, it is beneficial and recommended for the following conditions:

•    when started 8 – 12 weeks before a pollen season (in the State of Michigan, begin
using tree pollen sublingually in February, grass pollen in March and ragweed pollen in
June);
•    in infants and young children not old enough for allergy shots (usually less than 5
years of age);
•    in treating food allergies;
•    as an additional therapeutic option when allergy shots alone are not providing
satisfactory symptom relief;
•    for patients with moderate or severe asthma who are not considered good candidates
for allergy shots;
•    for patients with chronic sinusitis, often sick and not well enough to receive
allergy shots on a regular basis;
•    for patients with a real fear or dread of needles, especially children.

The most common side effect of SLIT is a local irritation in the mouth and under the tongue.
Itching in the mouth also occurs on occasion, but this itching is usually transient and does
not progress to a severe allergic reaction such as anaphylaxis.The cost of treatment is
approximately per vial, and vials should last at least one month. The total cost of
treatment will depend upon the number of vials ordered.