If you know me or have read almost any other post on the blog, you know that I am kind of obsessed with research. I think it’s important and use it to guide many decisions in my life, maybe too many. (For example, it probably wasn’t totally necessary to spend several weeks debating the merits of various down comforters.) As a therapist it wouldn’t even occur to me to develop a treatment plan for a patient that wasn’t guided by research. So you can imagine, that when it comes to my son, there is no such thing as too much research. Which is why this conversation I had at E’s last allergist appointment is both amusing and infuriating to me:
Me: How long should a food trial be? I’ve scoured the literature and can’t find any recommendations. I feel like it’s all about superstitions.
Allergist: You’re right, there really isn’t anything in the literature and it’s different for every child.
Me: Is it necessary to incorporate a break into a food challenge?
Allergist: What does the literature say? *she said with a smirk that told me she already knew the answer*
Me: Nothing, I can’t find anything1
Allergist: *shrugs* Like you said, it’s all Voo Doo
I love E’s allergist. She’s wonderfully down to earth and very aware of the literature and has no trouble acknowledging when there isn’t really a good answer. She often admits to going with her gut when we have a question about how to proceed. But sometimes I wish there were “real” answers based on actual data.
The thing about FPIES is that there are many children who react to multiple foods. So any food can be an allergen. And, of course, there is no way to know which foods are allergens until there has been a reaction. The only way to really know which foods are allergens and which are safe is to introduce one food at a time for a trial period until you know it is safe. I’ll never forget the helplessness that I felt after E’s first acute reaction and the confusion because we had no idea what caused it. From then on I knew that I had to treat E’s diet like one of my controlled scientific experiments.
It was clear to me that every time we introduced a new food into E’s diet we had to do an at-home food trial. The procedure for such a trail was anything but clear. I didn’t know how long a trial should be, how much food should be given, and then there was this whole issue of whether the days should be consecutive or if there should a “break.” I knew this was important and I wanted to follow the best methodology but had no idea what that was.
My literature search turned up almost nothing so I hit the internet and turned to the other FPIES experts, the parents who are living with it every day. If food trails were about trial and error, I figured I could at least capitalize on the trials and errors of others. (By the way, the Cradle Rocking Mama has a great post that summarizes some of her own unofficial FPIES parent polls regarding food trials.) I then threw in what I’d been told by allergists. But I quickly learned that the most important ingredients in the food trial recipe were my own experience, E’s history, and my gut feelings. Not exactly empirical but it’s all I’ve got. The way we’ve done food trials has been evolving since we first introduced solid food and will likely continue to evolve. We may never have the perfect method but we have something that can guide us through this mess that can be FPIES.
For me the biggest question was the length of the trial. When we first started introducing foods we did the typical “4 Day Wait Rule.” If there were no problems after 4 days we considered it safe and moved on. Most parents abide by this rule of thumb for the first foods they introduce. The idea is that if there are any issues with the food you will probably know within the 4 days. Most parents also abandon this rule at some point, once it becomes clear that their child is not reacting to anything. We were doing well with this method for several months as we introduced fruits and vegetables. However, our allergist recommended waiting 7 days for foods that were more likely to be problematic for our food-allergy-prone son. The list of the 7 day foods included meats, wheat, and eggs. I eventually decided that it was better safe than sorry and started giving all foods a full 7 days. I thought I was being conservative until the attending allergist at E’s soy challenge told me that I should try a food for 12 days before declaring it safe! The scientific literature was no help here, with some authors suggesting that a child would react after one or two exposures and some acknowledging that the number of exposures before a reaction is unknown. When I polled a Facebook support group, the other FPIES parents reported food trials that ranged in length from 3 days to 3 weeks!
While I wanted to scoff at the idea of a super-long trial, I had to rely on what I knew. An objective review of our data indicated that E’s reactions were always after a lot of exposures. This is what led to all of the confusion with his egg and coconut reactions. We trialled his birthday cake (made with coconut flour and a ton of eggs) for 7 days, per our allergist’s recommendation. He did fine. He then had a cupcake on his actual birthday (day 8) and more cake at his birthday party (day 9). He didn’t have egg or coconut again for a week or so until I made coconut flour banana bread and he reacted (day 10). This realization made me reconsider the 12 day recommendation, to be on safe side. Of course (probably because I’m crazy), I then started questioning everything that we had previously considered safe that may not have been eaten for at least 12 days. So we embarked on secondary food trials of all of E’s “safe” foods. Not only was this annoying, but it held up the introduction of new foods. Still, better safe than sorry – I had to KNOW what was safe and what was still risky.There are worse things than a 12 day chocolate trial 🙂
Now that I had decided on a 12 day trial period I needed to decide how much food to give E each day of the trial. There seem to be a few schools of thought on this one. Some people start with very small amounts (i.e., a teaspoon) and increase the serving very slowly over several days while others allow their children to eat as much as they like, regardless of how much it is. I went with my allergist’s recommendation, which also just felt right to me. She recommended that we start with a small amount and increase over a couple of days. Depending on the type of food, I usually start with one piece (such as on piece of rotini for the first day of a wheat trial) or one ounce (fluid or weight, whichever makes sense). I then increase by 50% or 100% (honestly, it’s based on whichever feels right and looks right based on the serving size and what E ate the day before) each day until we reach a full serving size, which I aim to meet around day 5. I then continue to give a full serving for the next several days. If everything seems to be going well I increase the serving size on the last day or two. I try to give him an “overdose” of the food during the trial, so I never have to worry about him eating too much later and having a reaction when we aren’t ready for it.
Timing is also important and a personal preference. Some people always give the trial food in the evening when both parents are home and can evaluate and treat symptoms. However, I think the majority of parents, myself included, prefer to introduce the trial food first thing in the morning. This ensures that he’s hungry and will likely eat the whole portion and also gives me all day to watch for a reaction.
Who doesn’t love tuna first thing in the morning?
Then there was this idea of “the break.” I was researching and trying to figure out FPIES for months before I even heard of this. It turns out that some parents incorporate a “break” into their trials, during which they stop giving the food. Then they reintroduce it several days later and continue until they reach the end of their trial period. There is actually one paper (6) that mentions this practice. The idea is that if a child is having a very low-grade reaction that is primarily taking place in the intestines and may be accompanied by some nonspecific symptoms, like loose stool or fussiness, it might be impossible to distinguish. However, it seems that sometimes when the food is reintroduced after a 2-3 day break, the reaction will be more severe and acute. When I looked back at all of E’s recent acute reactions – egg, coconut, shellfish, soy – all occurred following several days to weeks (or even months) of not having the food. I was sold on the necessity of the break but am still uncertain as to when I should institute it. My unscientific Facebook survey responses were anywhere from after trial day 4 to after day 12. Honestly our breaks tend to happen on their own – I run out of the food or E is going to be with his grandparents for the day or we have a busy day scheduled and no time for a reaction. But the scientist in me wasn’t comfortable without a real protocol so once again I relied on our past experiences. I now aim for a break around day 9, given that E’s reactions have been around day 10 or 11, following a break. I try to do at least a 3 day break, but don’t worry too much if it’s longer.
So, there it is. Every new food for E begins a food trial that lasts a minimum of 15 days. We start with a low dose, increasing it slowly over about 5 days. We then give an appropriate serving size for another 4 days. We try to give him the food every day (mostly to get through the trial as quickly as possible) but I don’t worry too much if we take a day or two off for whatever reason. After about 9 days of exposure to the food we take a 3 day break. Then we reintroduce the food for about 4 more days, the last two of which are at “overdose” amounts. Remember, the most important aspect of the food trial – during the trial no other new foods can be given. If you introduce another new food during the trial and see a reaction, you’ll have no way of knowing which food caused it.Enjoying the end of a food trial with some friends
Is this system necessary? I don’t know, maybe not. But it provides me with so much piece of mind that it’s worth the stress and hassle. Now I can know for sure which foods are safe. Any food can be an allergen and I’ve had my fill of surprise reactions and never want to try to get vomit out of the car seat again! There have been a couple of times when Jonathan and I considered giving E an un-trialed food but the bottom line is that it’s not worth it. The stress of having a reaction that we are not prepared for is too great. The chance of ending the day covered in vomit, or worse – in the hospital, is too scary. This system might not even catch every allergen, it is a work in progress but so far, so good.
Knowledge is power and I’m always trying to get as much power as I can over FPIES.
I’m always interested in what other FPIES parents do for food trials. Does it look like ours? What do you do differently?
UPDATE: Check out my newer post, Food Trials: Variations on a Theme, to see how our trial protocol has evolved and other ways that we trial food.