The Promise and Problems of Oral Immunotherapy for Food Allergy

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With only a casual understanding of Oral Immunotherapy (OIT) some people assume that simply feeding children a bit of their problem food, in order to develop a tolerance, is safe.

This is not an assumption any parent of a food allergic child wants others, especially relatives, to make. Giving children even a tiny amount of their allergen - without medical monitoring - is always unsafe. Understanding more about OIT makes it clear why this is so:

  • Monitoring A Must. OIT is still an experimental allergy treatment. Participants in OIT clinical trials are screened for suitability. Those that qualify are monitored by highly trained professionals while given minuscule amounts of the food allergen they react to. Over an extended time period, the amount of allergen ingested is slowly increased.
  • The increase of allergen doses always takes place in a controlled setting. Once the highest tolerated, or maintenance dose is safely reached, it can then be administered at home.
  • Medical monitoring is important during OIT since reactions to the tiny allergen doses can occur. Most of these reactions involve skin or mouth rashes and itching, upper respiratory symptoms, or abdominal discomfort. A small number of individuals experience reactions, mostly mild, to their maintenance doses.
  • Desensitization vs Permanent Tolerance. At present, OIT causes desensitization, a state in which a person can tolerate more of the problem food, reducing their chance of severe or life-threatening reactions. This protective effect requires a daily, uninterrupted intake of the allergen. If daily dosing is disrupted, the allergen protection is significantly diminished, or may be lost.
  • It is not clear whether OIT establishes a permanent oral allergen tolerance. A true tolerance is an absence of symptoms following exposure to any amount of the allergen. If OIT is continued long enough, it may eventually create a permanent tolerance in some individuals. but this is yet to be determined.
  • Imperfect Protection. Though OIT results are encouraging, the desensitization created by OIT is not perfect. Some individuals on maintenance doses experience allergic reactions to previously tolerated amounts of the problem food. These reactions are associated with exercise or other physical exertion after dose ingestion, dosing on an empty stomach, during menstruation, viral infections, asthma aggravation, or when stressed.

Data analysis indicates about 50 to 75 percent of children treated with OIT achieve desensitization, protecting them from severe reactions owed to accidental allergen exposure. These results are remarkable, and have provided allergy and anxiety relief to many individuals and their families. However, questions remain.

Researchers still wonder about optimal dosing amounts, the level and duration of protection afforded, effects of age on OIT outcomes, the types of food allergy most responsive to treatment, and the need for patient protections during home maintenance dosing.

Once the questions are settled, and if the risk-to-benefit ratio comes out in favor of OIT, this experimental treatment may become a common one—but there will still be tight protocols in place to ensure patient security. It will never be safe to just give someone a bit of their problem food.

Sources: Medscape; Food Allergy Canada Photo credit: Emran Kassim

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