3 Signs Your Child Might Be Outgrowing FPIES

One of the best days in the life of a child with FPIES (and their parents) is the day they can finally declare themselves free from FPIES. After months or years of trialing one food at a time and holding their breath, those kids are finally free to eat what every other child can eat. So when do you flip the switch from trialing one food at a time to complete freedom?

There are several signs that signal the end of FPIES might be in sight:

1. Your child starts to get several passes in a row or long stretches of time where there are only minor reactions.
2. You get down to a very manageable list of fails to avoid
3. Your child starts to pass previously failed foods without issues

Of course, the biggest indicator that your child is FPIES free is when they are able to successfully pass all of their previously failed foods. Sometimes this will require one or more oral food challenges before a doctor will officially declare your child free of FPIES. 

What age do kids start to outgrow FPIES?

The average age for kids to outgrow FPIES is somewhere between 3-5 years old. For some children this is true – some kids even outgrow their FPIES earlier than that. One study showed that nationality and the type of trigger food can impact the age that a child outgrows it. Oat and Rice can be outgrown around age 4 or 4.5, respectively. The average for soy is 12 months, but the range of years it takes to outgrow is anywhere from 6 months up to 22 years. The range for cow’s milk is similar – 12 months old is the average in Korea, 3 years is the average in Israel, and 7 years old is the average for the USA and UK.

 Some kids are much older when they outgrow their FPIES, not outgrowing their last few triggers until late childhood or their teen years. Usually the list of foods those kids react to is much smaller by then, and they may just be down to a handful of foods to avoid. 

How do you know when your child is starting to outgrow FPIES?

For some kids, outgrowing FPIES feels like magically flipping a lightswitch. One day, they may accidentally pick a cheerio up off the floor and eat it, and everyone in the family waits the usual 2-6 hours, but nothing happens. So, they try oats again, and nothing happens. Then, they start trying other triggers, and again…no reactions. I’ve seen it described this way over and over by moms with toddlers who are suddenly FPIES free out of nowhere. This is the reason that the 3 year old age has the nickname “magic 3” in the FPIES community – sometimes it feels like the allergies magically disappear around that age. 

For most kids though, outgrowing FPIES allergies is actually a process. There are small signs along the way that start to signal the beginning of the end. 

  • You start to get several passes in a row or long stretches of time where there are only minor reactions.

The first sign most parents see is that the child will start to pass new foods during food trials, and those passes start to add up. They may have a few months of passing one food after another with no issues, or they may have only minor symptoms that they are able to push through. Usually at this point, parents will start trialing several foods at a time, or they will move to trying foods with more than one ingredient.

If introducing foods with several ingredients is going well, you can usually start to shorten the length of the trials, testing new foods for a couple of days and then moving on. 

If they start to fail foods or start to have major reactions, then back off and start trialing foods as before. With FPIES allergies, it’s much easier to go slowly and build up to new foods than it is to rush things and stress your child’s body. We failed a lot of foods early on when we were so worried about finding safe foods that our kids could do. We were trialing foods one after another just trying to find safe foods, and we ended up collecting a ton of failed foods that we had to wait a full year to retry. 

  • You get down to a very manageable list of fails to avoid

Once you get down to a smaller list of triggers, life starts to get a lot easier. This can also be a signal that your child is starting to outgrow FPIES. Babies who once had 5 major triggers that would cause acute reactions might be down to one or two. Toddlers with a list of 30 chronic reactions might be down to just ten. These are just examples, but once your fail list starts shrinking dramatically, it can be a sign that things are starting to improve. 

I keep a spreadsheet for each of my kids that shows all of their trigger foods and how long ago we last tried that food. Every few months I update the list (or whenever my kids start to fail new foods). The last few times I’ve gone in and updated their lists, the difference has been incredible. My daughter is four and a half years old and while she’s not close to outgrowing it entirely, we are down to a handful of major triggers like soy and oats. My son is three and a half and he still has a few major triggers and quite a lot of smaller triggers. Even still, the last time I updated his list the amount of foods we have to avoid was cut in half, and his list of safe foods doubled. 

  • Your child starts to pass previously failed foods without issues

The last sign that your child might be outgrowing their FPIES is that they are able to pass foods that they previously failed. Current research suggests waiting 12-18 months to re-trial foods that have caused a reaction in the past. This means that even if you have an accidental exposure to a food on the fail list and it causes a reaction, you will need to start the clock over and wait another 12-18 months to retry that food. Sometimes there are happy accidents and a child will outgrow a trigger food before that timeline, but this is suggested because it gives the child’s immune system time to “forget” that their body reacted to that food.

When you get to the point that your child is starting to pass trials for foods that were fails, you can start to work up to trying more high risk foods like milk and soy. Some of those foods just simply take longer to outgrow though, so work with your doctor on what timeline they want you to start those trials. They may even have you perform Oral Food Challenges to some of the bigger trigger foods. Oral Food Challenges are performed in a doctor’s office or hospital setting, and usually an IV line is placed before the trial begins. This is done just in case an acute reaction happens, so that they are able to administer IV fluids to your child quickly. It can be difficult to start an IV on a small child once they start vomiting and get dehydrated, so having the IV placed before the challenge can be helpful in case there is a reaction.

Unfortunately, just like much of FPIES life, the process of outgrowing triggers is all very individual. It can be different for every single child. So, just because you don’t see as many failed foods or your child is passing lots of trials, it doesn’t mean that they will outgrow FPIES within a few days or weeks. There is no set timeline because every child is different. There are some kids that hit a great streak of passing foods left and right and then they hit a set back where they may fail several foods in a row. Some kids will hit all three of the signs on this list and will still have FPIES to several foods for months or even years. It all depends on the child and how well their body is able to overcome the triggers. 

Nowak-Wegrzyn A, Chehade M, Groetch ME, et al. International consensus guidelines for the diagnosis and management of food protein-induced enterocolitis syndrome: executive summary-workgroup report of the adverse reactions to foods committee, American Academy of Allergy, Asthma & Immunology. J Allergy Clin Immunol. 2017;139(4):1111–26. e1114.

Ruffner MA, Ruymann K, Barni S, Cianferoni A, Brown-Whitehorn T, Spergel JM. Food protein-induced enterocolitis syndrome: insights from review of a large referral population. The Journal of Allergy and Clinical Immunology Practice. 2013;1(4):343–9.