Until recently, avoiding an allergenic food was the only practical option for patients with food allergy like Peanut allergies. However, even the most careful patients with food allergies feared reactions caused by eating contaminated or mislabeled food. Now, scientists have devised a treatment that can enable patients to eat the food they’re allergic to without fear of a reaction. It’s called “oral immunotherapy” or “oral desensitization”.
In oral immunotherapy, the patient, with their doctor’s help, basically “teaches” their immune system to tolerate a food it over-reacts to. They eat the food in small but increasing amounts to re-introduce it to their system without causing a reaction.
Since food allergies can be lethal, only a Board-Certified Allergist should administer oral immunotherapy. The initial treatment should only be administered in a hospital or medical center – not at the patient’s home. Oral immunotherapy does carry some risks, most notably anaphylaxis, a severe and potentially fatal allergic reaction. It is, therefore, a treatment that should be used only after a thorough discussion with the Allergist.
What does the procedure involve?
Oral immunotherapy takes time. The procedure begins with a “desensitization day” during which the patient is given doses of very dilute versions of the allergen over a seven-hour period. These doses prepare the patient’s immune system to accept dilute preparations of the allergen twice a day at home. The allergist increases the strength of the doses every week over a six-month period. Eventually, the patient reaches their “maintenance dose,” at which point they can tolerate the allergen and no longer fear the possibility of accidentally eating it. They are also less susceptible to anaphylaxis.
When carefully and successfully done, oral immunotherapy can change a patient’s life for the better. It lets patients enjoy the food they had once been allergic to. Even people who have multiple allergies can be helped – but the allergies must be treated one at a time.
What are the limitations of oral immunotherapy?
Oral immunotherapy does have its limits. It is only effective with IgE-mediated food allergies, not food intolerances. It cannot be administered to patients who can’t describe their symptoms to the health care providers. Therefore, a patient has to be at least five years old and have good communication skills. In addition, patients with asthma are not good candidates for oral immunotherapy until and unless their asthma can be controlled.
How eﬀective is Oral Immunotherapy for food allergens?
Desensitization can be achieved in approximately 50-80% of children for any food allergy, including peanuts. The rate of permanent tolerance is unknown (ex. being able to tolerate the allergen without taking a daily maintenance dose), but appears to be low for foods such as peanuts; the longer the duration of Oral Immunotherapy (OIT), the better the outcome of the treatment.