10+ Things to Know About OIT for Food Allergies

Recently, we decided to have our children try oral immunotherapy (OIT) for nuts. OIT is just one of many treatment options emerging. This was a huge, agonizing decision for us and we went back and forth several times for months before we finally committed. Read this post, “Stopping OIT at One Nut,” for where we are with OIT today.

My takeaway

This post is a summary of the key information (but a long list, nevertheless) that I found helpful in making our decision and knowing what to expect once we started OIT. I gathered it through reading online resources, quizzing OIT providers, and lurking on Facebook private practice OIT groups.

  1. OIT for food involves ingesting increasingly larger amounts (often referred to as “doses”) of the allergen until you reach your target amount of desensitization. You decide what you want your target to be.
    • Some people just want to be “bite-proof” which is being able to accidentally ingest the equivalent of say, a few nuts, and not have a reaction. Others want to be able to eat a lot of the allergen.
    • Desensitization is not a cure – OIT desensitizes your body to the allergen so that you don’t react, but you are still allergic and you may still have reactions (more likely to be minor, but reactions nonetheless) to the allergen.
    • There is about an 80 something percent success rate in clinical trials. OIT providers say that success rate is more like 90+ percent because of private practice’s ability to tailor the treatment to the patient. In clinical studies, participants may have to drop out if they can’t keep up with the trial’s dosing schedule, etc.
    • Doing OIT is often referred to as a program of X number of months, after which you graduate and go into the “maintenance phase.
  2. The length of the program is determined by the patient’s goal, how well the patient tolerates the doses and the gradual increase, your own scheduling availability for increasing your dose (aka “updosing”)  at the OIT office, and your OIT doctor’s protocol. 
  3. The maintenance phase, at this point in time of medical knowledge, is basically the rest of your life! Once you stop increasing your doses at the OIT provider’s office, you go into maintenance phase. If you ended your program at a dose level of say, 3 peanuts, then you are supposed to eat the equivalent of 3 peanuts a day for the rest of your life. After being in maintenance phase for a couple years (time varies by patient), you may be able to reduce your dosing to twice a week (like Mondays and Thursdays) or every other week, etc, but it all depends on the patient.  
  4. If you don’t finish OIT or quit during maintenance, you may lose whatever desensitization that you have gained, but in theory, you don’t become more allergic because you tried OIT. 
  5. OIT in practice looks roughly like this:
    • First dose appointment – Your initial dose day may involve taking very, very small amounts of the dose up to a pre-determined total dose or until there is a reaction, known as an eliciting dose. This depends on your provider’s protocol. The amount that you stop at is the amount that you will be ingesting daily at home until your next appointment. 
    • Dosing at home – you take the dose amount of the allergen daily at home, with applesauce (applesauce may be best if you experience problems with other foods) or any foods you like (to either hide the taste, or ensure you get the entire dose). Prior to the dose, you should have a meal or a high carb snack. Apparently, this helps to minimize reactions. 
    • Updose appointment – you return to the doctor’s office after a minimum of 1-2 weeks on your dose (or more depending on scheduling and how the dosing goes). You do this until you reach your target dose and enter the maintenance phase.
    • Rest period – for 2 hours after each dose, you should not exercise, shower, or do anything that may raise your body temperature which is currently believed to increase your chances of a reaction. One well-known OIT provider explained the idea that an elevated heart rate increases your blood circulation (which may have histamines from the dose) and therefore spread your body’s reaction. Nevertheless, reactions can still occur after the rest period and also during maintenance.
    • Vacations/sick/exceptions – you’re not supposed to dose or fully dose when you are sick (more likely to have reaction due to increased inflammation levels in the body or higher body temperature due to fever), traveling (elevation, far from hospital, time changes), or doing things that may make it difficult to follow the rest period. After these exceptions, you contact your doctor to get instructions for slowly building back up to the dose you were on.
  6. The protocol and guidelines you follow will vary depending on the OIT provider you choose as well as on the patient’s needs and progress. There is no standard protocol and if you consult a few OIT providers, you will find that each doctor’s protocol varies slightly. These are some of the differences that I found: 
    • Dosing schedule – number of doses per day seems to range from 1 to 2 doses per day. Increasing the dose can also vary from one increase per week to every two or three weeks. Some providers say you should only dose in the mornings as there seems to be an increased likelihood of having a reaction to an evening dose (rising cortisol levels, etc.). The schedule may also be modified due to the patient’s progress. 
    • Rest period: in addition to the 2 hour rest period, some providers say you should not exercise for 1 hour before your dose. Some providers have reduced the required rest period from 2 hours to 1 hour.
    • OIT is available for most of the top allergens (milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat and soybean), but depends on your provider.
    • Multi-allergen vs. one allergen OIT: You can do OIT for multiple allergens at once. Some providers recommend it, others don’t. I preferred not doing multi-allergen OIT because I didn’t like not knowing which allergen the body was reacting to.
    • Zyrtec vs no Zyrtec: some providers require that Zyrtec or some anti-histamine is used prior to dosing. Others say it is optional. Some doctors require it for updosing and some doctors ask that you don’t use it on updose days. Pretty confusing. After some inquiry, I understood that the anti-histamine was mainly for the patient’s comfort and to avoid experiencing mild reactions. It wouldn’t prevent the chances of you having anaphylaxis if you took it nor would it make you physically any less desensitized to the allergen in the long run. One provider also explained that routine Zyrtec is highly recommended for the pre-teen ages 7-12 because they can generally be more anxious about OIT and having minor reactions can cause them to develop more anxiety over the allergen.
    • Other medications during OIT: Antacids, asthma medications are the most popular other drugs that you may find are needed during the course of OIT. Apparently, it’s important to keep asthma under control during OIT as uncontrolled asthma increases the likelihood of anaphylactic reactions. Even asthma that is exercise-induced or environmental allergy-induced may be very subtle (and never a problem for you or your child previously) is a red flag for OIT providers. If there are some warning symptoms such as needing albuterol or corticosteroids during colds or having persistent coughs, etc. during allergy season, OIT providers will likely put you on an asthma medication such as Qvar, Flovent, or Singulair. We had a bad reaction to Qvar and ended up treating through TCM with some success.
    • Xolair (an anti-IGE medication) is sometimes recommended for highly allergic, high risk individuals. One provider said that she would not normally start considering it unless the patient’s IGE levels were >100. If used, you would need to start it two months before you begin OIT. To take effect, Xolair would need to be given at 1 shot/month for 3 months. Xolair is currently only approved for chronic hives, so unless you have been diagnosed with chronic hives, you would likely need to pay out of pocket for the shot at ~$1300/shot. However, you would be able increase your dosing much more quickly than you would without Xolair. I’ve read a post that talked about providers who provide the drug for free in order to get through treatment faster – interesting post that hints of the provider drama behind OIT.
    • Note: the medications come with side effects. All of the medications listed above (anti-histamines, asthma medications, Xolair, etc.) seem well-tolerated by many, but all come with some troubling side effects related to emotions and behaviors that seem to affect a significant number of users. These are often reported on the Facebook OIT parents groups.
  7. Anyone is a candidate for OIT and potentially treatable.
    • However, it’s believed that the younger you are when you are treated, the better chance you have of becoming not-allergic as opposed to just desensitized. This is because the young immune system is still developing and capable of resetting. Think the preschool set. One OIT practitioner told me that even 6 year olds appear much less likely to reach “no longer allergic” status.
    • At the same time, I’ve heard from some moms that their kids (who started OIT around 10-12 years old) are not allergic anymore and can eat as much as they like of the allergen. 
  8. Maintenance phase doesn’t mean that you are home free:
    • Some OIT graduates have reported reactions during maintenance if they don’t follow the rest period
    • People do experience reactions (even anaphylactic ones) after they have reached maintenance (EVEN if they have followed the rest period!) and even some with very low IGE numbers
    • Hormonal changes (during puberty or periods) can sometimes cause reactions
  9. The only current way to know if you are no longer allergic is by having low enough IGE levels and negative skin prick test and passing a food challenge. This seems unreliable to me, however. In the same way that some people may develop allergies later in life, it seems to me that even if you no longer clinically present as allergic at one point in time, you could always redevelop the allergy. My conclusion is treated patients will always want to have the Epipen handy and you will always want to be careful of what you eat and how you feel. 
  10. Costs with and without insurance 
    • With some insurances, your coverage can be up to 100%, minus co-pays. The providers typically bill your visits as specialist office visits and food challenge visits (like any other allergy provider would). If your insurance covers regular allergist visits, then they would probably cover OIT because they don’t register it as anything different.
    • If you don’t have insurance coverage, or your provider doesn’t take insurance, it seems like out of pocket costs could be $10K – $25K per allergen/year, depending on your goals and personal allergy situation. I got this cost range from a Facebook group for families doing OIT and one of the providers we visited.
    • There are often clinical trials available for certain allergens, but the cons seemed pretty significant. In some trials, you don’t know if you are the control group and in others, you have to keep up with the trial’s schedule of increasing doses or whatever other parameters they are testing for. Otherwise, you could be dropped from the trial if you cannot keep up with the dosing schedule, and so on. However, trials are free for the patient.
    • There is a new allergy “drug” called Palforzia, which has been FDA-approved and they may start to change (probably increase) the cost structure of OIT treatments. The drug is essentially pre-measured peanut flour in the form of a pill, so you don’t have to do it yourself and which I guess is supposed to help standardize the dosing protocol of OIT providers.
  11. Much is still unknown about how the body responds to OIT over time and I think that is reflected in the variability of protocols from one OIT doctor to another. This is also the reason that many allergists don’t feel that OIT is ready for private practice
  12. There are a range of things that could be reactions (other than anaphylaxis) and the problem is that you will often be unsure whether it’s a reaction or just something else that you might get in everyday life. Range of reactions:
    • Itchy mouth or throat
    • Runny nose
    • Stomach ache
    • Hives
    • Rash
    • Vomiting
    • Coughing
    • Feeling something in the throat
    • Eosinophilic esophagitis (EoE
  13. OIT is introducing a new habit into your life and family lifestyle – like brushing your teeth and flossing, dosing is something you will have to remember to do everyday or on some schedule. 

Thoughts after starting OIT

For us, OIT is turning an “unknown” into “slightly more known.” Choosing to do OIT is not a “no-brainer” and is a very personal decision. OIT takes more time and energy than simply nut avoidance, especially as it appears that patients continue to be at risk for reaction even after “successfully” completing immunotherapy. Unlike some who have extensive allergies, our nut allergies were not affecting our lives significantly and we wondered if we were bringing more risk, concerns, and health issues into our lives. On Facebook groups, you will see other families wondering the same thing.

However, I will say that on the first day of dosing, after I saw that my kids were actually able to ingest very small amounts of their allergens, I realized that I was getting some answers. I had never known how allergic they might be. I hadn’t known whether they could even touch a nut. We had always worried that if we kissed our kids after eating nuts that we might cause a reaction. We knew nothing about their reactions – it was just this big question mark. Now we’re beginning to know a little.


I read a lot of articles and studies about OIT and included some of them here.

Informative OIT starting points – helpful for understanding what it is about and what doing OIT entails (the top 10 myths section in particular has become much more detailed since I first came across it in early 2019, so if you haven’t reviewed that page in awhile, check it out again):

Articles about OIT

Determining thresholds for OIT

Facebook groups for OIT patients or parents of OIT patients (just a couple here, but there seem to be lots of these, so worth checking them out and finding one helpful to you):

Personal stories about OIT experiences (below are just a few – you can find many online):

Articles with some skepticism around OIT:

People don’t maintain the same level of desensitization when they stop OIT, proving that maintenance is needed for most people:

Interesting article on SoCal Food Allergy Institute, a well-known food allergy treatment center that uses a more customized, yet similar approach to OIT:

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