Recurrent vomiting in a baby – could it be FPIES?

The Pediatric Insider

© 2019 Roy Benaroch, MD

Not every diagnosis is easy, and not every diagnosis can be made correctly from a first impression. FPIES is one of those tricky ones, and parents and docs can get it right by paying attention to clues and keeping an open mind. Let’s start with a story, and then we’ll talk about FPIES (hint: these are not the kind of PIES you want to eat!)

5 month old Sally has had two trips to the emergency department and one to her pediatrician for vomiting episodes. Each time, she has a sudden onset of vomiting, diarrhea, and lethargy, and gets sick quickly – twice she ended up needing IV fluids. She recovers in a few days and seems to feel better. Overall she’s usually a happy baby, but her weight has been concerning. She’s not growing as fast as she should. Sally attends day care and has two older siblings.

What do you think? Vomiting illnesses are very common, and they’re usually caused by viruses (like Norovirus, especially this time of year.) If there had been one or two episodes like this, and Sally otherwise seemed OK, the story wouldn’t necessarily seem unusual. After all, she’s in day care, and probably is exposed to a lot of yuck.

But, still, there are some clues that there’s more to this story. Most vomiting illnesses do not require IV fluids – Sally’s needed that twice. And overall her weight isn’t great. Could there be a connection?

Making a medical diagnosis is like detective work. First collect the clues (which are almost always in the story), then find a diagnosis that fits. But keep in mind that every diagnosis is a “work in progress” that may have to change as new facts come it. Sally seemed like she had a viral gastroenteritis (a “tummy bug”), until the story continued to unfold. I warn medical students and residents: don’t lock yourself into a diagnosis. Stay curious!

Sally’s “mystery” diagnosis turned out to be “FPIES”, or “Food Protein Induced Enterocolitis Syndrome.” It’s a rare-ish allergic condition usually affecting young babies and toddlers, who react to certain foods with episodes of intense vomiting, often with diarrhea. Sometimes FPIES can be more of a chronic presentation, including lower-grade, ongoing symptoms like poor growth. Common triggers include cow’s milk and soy, but also grains like oats and rice. There’s no test for FPIES – ordinary ‘allergy testing’ is often misleading – so the diagnosis rests on the story.

The prognosis for PFIES is very good. Children usually outgrow it. The trick is making the diagnosis early, so parents can avoid the trigger food(s). And the key to making the diagnosis is paying attention to the clues your patients and their parents are trying to tell you.  I tell my medical students and residents: stay curious and pay attention!

More about FPIES

Interested in learning more about how doctors think, and how the best diagnosticians work through the clues to figure out the answer? I’ve made three courses about this, available from The Great Courses, in audio or video formats. They can be watched or listened to in any order. You can buy ‘em (money back guarantee!), or stream them from TheGreatCoursesPlus.

• Medical School for Everyone: Pediatrics Grand Rounds – Pediatric mystery cases for you to solve – get in the mind of a pediatrician! (Me!)
• Medical School for Everyone: Emergency Medicine – Fast-paced mystery cases from the ED – and in this course you get to juggle multiple cases at once. Stay on your toes!
• Medical School for Everyone: Grand Rounds Cases – Step by step, hear the story, listen for the clues, and figure out the case! (This was my first course, and it covers a broad range of medical cases.)

Norovirus: The real “stomach flu”

The Pediatric Insider

© 2016 Roy Benaroch, MD

Informally, it’s sometimes mistakenly called “the stomach flu” or “a tummy bug”—an illness with some aches and fevers, but mostly vomiting and diarrhea, that often occurs in mini-epidemics in households, daycares, and schools. One kid gets it, and the rest of the dominoes fall, in a most unpleasant and stinky manner.

Yuck.

The illness has nothing at all to do with influenza, by the way. Influenza is a respiratory virus, spread by mucus, that mainly causes aches and fever, along with cough and sometimes some vomiting or abdominal pain. Influenza cases are concentrated during a few months of winter, and there’s a vaccine that can prevent at least some cases.

The “stomach flu” isn’t a flu at all. Technically, we call it an “acute gastroenteritis”, with inflammation of the stomach and intestines, sometimes shortened to just a “gastro” or “AGE”.  These days, the most common cause, year-round, is a nasty and clever little virus called “norovirus”, or “noro” for short. (Docs are always in a hurry. We prefer short words.)

Here’s a lovely thought: volunteers who touched a surface smeared with 30 microliters of infected feces—that’s about half of a drop—all got enough virus on their hands to potentially make them sick. And, get this, if they then touched a doorknob or telephone or another surface, that would transfer enough virus to get the next person sick. In fact, 10 people in a row, serially touching surfaces one after another, would all potentially get sick after the first person touched that first surface, with half a drop of stool. Seriously. Someone did this experiment.

The incubation period between contact with the virus and symptoms is 12-48 hours, though people who are becoming sick become contagious before symptoms start. Though the illness itself is usually brief, typically lasting only a few days, virus continues to be shed in the stool for several weeks, and maybe at low levels for even longer. Both vomit and diarrhea can be loaded with infectious viral particles – and it’s so contagious that documented transmission has occurred in people just walking through an emergency department near someone who has been vomiting.

There is some good news. The virus itself cannot make you sick if it just gets on your skin. It has to invade your body through a “mucus membrane,” like your mouth or nose or eyes (this is true of almost all infectious, by the way—they need a break in the skin barrier or a wet membrane to get through). So as long as you wash your hands well before you eat or drink or touch your face, you ought to be OK.

“Wash your hands well” – that’s not so easy. A CDC-recommended decontamination handwash is 60 seconds of rubbing with soapy water, a 20 second rinse, and drying with disposable paper towels. Do that before and after every patient (as every health care worker should), and by the end of the day your hands will be bloody cracked dry stumps (OK, maybe it’s not that bad. But my knuckles get pretty raw. I know, boo hoo me.) Hand sanitizers containing 70% alcohol help, some, though they’re no substitute for full-on soapy water hand washes.

If vomiting and diarrhea does strike your children, here’s what you ought to do:

• Keep them home. Please, please keep them home.
• Wash hands well, and wash hands frequently.
• Decontaminate surfaces with diluted bleach. Standard detergent sprays help, but bleach is da bomb.
• Offer frequent, small sips of fluids. They don’t have to eat (and don’t make ‘em eat if they don’t want to), but continued fluid intake is essential.
• Seek medical attention if your child shows signs of significant dehydration, especially listlessness, an inability to drink, or very little urine output.

Preventing the dreaded yuck

The dreaded tummy bug: vomiting, diarrhea, misery. Holly wanted to know, if one child gets it, what’s the best way to prevent it from knocking out the rest of the family?

In medical lingo (you know, we can’t use normal words like normal people), the dreaded tummy bug is known as “gastroenteritis.” Most commonly, it’s caused by a number of different viruses. Sometimes, it’s called a “stomach flu”, though it has nothing at all to do with influenza. The common symptoms are nausea followed by vomiting followed by diarrhea, usually in that order, and usually all occurring within a day or so. Sometimes there’s a fever, or some abdominal pain, but that typically isn’t severe.

Vomiting or diarrhea, though seldom both, can also be caused by food poisoning. When a family catches this, everyone gets sick at the same time—how special! With an infectious (usually viral) gastroenteritis, one person gets it, then another, then another, then it’s time to move to a different house, or at least burn all of your clothes and sheets.

If you can’t afford to do that, it might be more practical to follow these steps for prevention:

1. Wash your hands.
2. Wash your hands when you leave the bathroom.
3. Wash your hands before you eat.
4. Wash your hands again.
5. Wash your child’s hands.
6. Wash your child’s hands when she leaves the bathroom…
7. …you get the idea.

Purell or a similar brand of alcohol-based hand sanitizer can protect against many infectious, but if your hands are “visibly soiled” you need to do a thorough wash with lots of sudsy soap and running water. What kind of soap doesn’t matter (antibacterial or medical soaps are not more effective than ordinary soap), but hand washing technique is important. You need running water and friction as you rub, and it ought to take as long to wash your hands as it takes to sing “Happy Birthday.” And blow out the candles.

Mild belly aches and vomiting

Holly posted, “My 4 year old has recently been complaining of ‘tummy aches’ during different times of the day. She hasn’t been ill, running a fever, or consuming anything out of the ordinary. She has vomited several times in the last few days. Once she has emptied her stomach, she seems to feel fine. Later, however, a tummy ache returns. Are there any OTC meds ok to give a 4 year old that can help settle an upset tummy? Since no other symptoms of illness are apparent, how many days of occasional vomiting should be dealt with at home before calling the doctor’s office? Since no one else at home is getting sick, is it ok to send her to school?”

Ways to settle an upset tummy begin with some non-medical approaches, like making meals small, and staying away from foods that are rich in fat or protein. Sips of things like clear liquids or cola seem to help. A few studies have looked at ginger as a treatment for nausea, at it is probably effective—but I’m not sure you’ll get a four year old to gnaw on ginger. Most ginger ales contain only artificial flavors, not real ginger root.

A few safe OTC remedies include antacids like Maalox or Mylanta, or a medication for nausea called Emetrol. Pepto-bismal can soothe an upset stomach and help with nausea, but there are some people who advise against its use in children because it contains an aspirin-like ingredient. In the past, taking aspirin during an infection with influenza or chicken pox was associated with a serious liver condition called Reye Syndrome. Though the ingredient in Pepto has never been linked to Reye Syndrome, some people are still leery of it.

As long as she’s overall feeling well, I don’t think a trip to the doctor’s office is warranted for several days. But if this persists, she should be seen. Since she’s vomiting a few times a day, the most likely diagnosis is a viral infection. It would be best to keep her out of school for the protection of the other children until she is well. I know this isn’t always possible for working families, but keeping her home is the best way to prevent sickness from spreading to other children.