Food Allergy Treatment: Are there predictors of success?
Are there predictors of success with food allergy treatment? Yes, we are confident there are. Based on more than five years of experience with treating life-threatening food allergy with a process called oral immunotherapy or OIT, the Dallas Food Allergy Center (DFAC) has gained valuable evidence that gives hope to millions.
Our treatment of food allergy involves giving the patient a very small amount of their problem food ranging from 1/100,000th of a peanut to 1/10,000th of an egg and gradually increasing the amount of their exposure until they have reached their target.
Generally, the target dose is a standard portion of the food; ½ of a peanut butter sandwich, 8 ounces of milk or one egg. After the first day of treatment when many very small dose changes are made, patients eat the same amount of their problem food twice a day for a week and then return to be challenged with the next dose.
If all goes well, it takes about three to four months to reach the target. After that, they need to take a maintenance dose once daily for at least three years.
A preliminary analysis of the first 233 treated patients suggests that, of the factors examined, a history of a severe reaction and the level of allergic antibodies influence whether or not a patient will reach their treatment target. This group comprised patients allergic to cashew (3), egg (34), milk (60), peanut (128) and wheat (3).
Patients discontinued OIT because of: reactions-12; GI problems-11; did not follow up-5; anxiety-3; siblings with reaction-2; difficulty taking doses-1; moving away-1.
The overall success rate was 83%, but it varied by food. While 80% of peanut allergic patients and 87% of those with milk allergy reached their target, 94% of those with egg allergy and all the cashew and wheat allergic patients met their goals.
Patients who dropped out of treatment were more likely to have had a serious reaction before starting treatment. Only 50% of successful patients had a history of severe reaction compared to 71% of those who dropped out.
Although 94% of egg treated patients reached their target, the two who did not seemed to have higher levels of allergic antibody to egg. A similar relationship was not seen with either milk or peanut allergic patients.
All treated patients were at least five years old, both boys and girls and neither age nor gender predicted the outcome. 11% of patients had one or more reactions that were treated with epinephrine. Having such a reaction made it less likely that the treatment would be successful.