FPIES in Babies: Symptoms, Risk Factors, and More

Understanding FPIES in Babies: A Guide for Parents

What Is FPIES?

Food protein-induced enterocolitis syndrome (FPIES) is a rare food allergy. It affects mostly children and infants. This allergy occurs in the gastrointestinal (GI) tract. It causes chronic, often severe vomiting and diarrhea.

Failure to Thrive
A child with a diagnosis of failure to thrive may have delays in many milestones, including:
  • height, weight, and head circumference
  • physical skills, including rolling over, sitting, standing, and walking
  • social skills
  • mental skills

The reaction typically begins after the infant or child consumes dairy or soy foods. The allergy may also appear when the infant begins eating solid foods for the first time.

Many children with FPIES will struggle to gain or even maintain a healthy weight. As a result, they may begin failing to meet growth milestones, including weight and height goals. Ultimately, children with FPIES may be diagnosed with “failure to thrive.”

What Are the Symptoms of FPIES?


Unlike other food allergies, an FPIES reaction is contained to the GI tract. The symptoms of a reaction may take several hours to appear. The delay in symptoms may make it harder to diagnose the allergy.

Symptoms of FPIES may also be confused with gas, acid reflux, or a stomach bug. The symptoms return after each exposure to the food allergen, so it’s the chronic and repetitive nature of FPIES that ultimately distinguishes it from a brief episode of tummy trouble. The symptoms of FPIES include:

  • chronic vomiting
  • diarrhea
  • dehydration
  • lethargy
  • changes in blood pressure
  • body temperature fluctuations
  • weight loss
  • stunted growth
  • failure to thrive

What Are the Risk Factors for FPIES?

Risk Factors

There are several risk factors for FPIES:

  • FPIES appears to affect boys slightly more than it affects girls.
  • The American College of Allergy, Asthma, and Immunology (ACAAI)) says that 40 to 80 percent of children with FPIES have a family history of allergic conditions, including food allergies, eczema, or hay fever.
  • If your child has been diagnosed with one type of food allergy, it’s possible they may have an additional allergy. FPIES is unlike most food allergies, which cause reactions within several seconds or minutes of contact with the allergen. Your child might have both types of food allergies.


All foods can cause an FPIES reaction, but certain foods are also more likely to trigger one. Milk and soy products are the leading causes of a reaction. Other food allergens that might trigger it include:

FPIES trigger foods

Most children with FPIES only have one or two food triggers. It is possible, however, for a child to have reactions to multiple foods.

How Common Is FPIES?

Experts don’t know how many children have FPIES. It ‘s considered a rare disease. In recent years, however, the number of FPIES cases has been increasing. Whether this increase is the result of wider awareness for FPIES or an actual increase in cases of the condition is unclear.

What Are the Treatments for FPIES?


If your child is exposed to the allergen that causes their reaction, you have several options for treating the symptoms. The treatment options depend on the severity of your child’s reaction and what foods trigger their reactions.

Steroid Injections

A steroid shot may help reduce the severity of your child’s immune response. This may lessen the severity of symptoms, too.

IV Fluids

If your child is experiencing severe vomiting, diarrhea, or dramatic changes in body temperature, you should see your child’s pediatrician immediately. Your child may need IV fluids for rehydration and to prevent shock.

Lifestyle Treatments

These treatments help reduce or ease the symptoms of an FPIES reaction. They don’t treat the condition itself, however. The treatments for FPIES are individualized to your child and their triggers.

If your child has a reaction to a milk product, including cow’s milk, soy, or another type, your pediatrician may recommend a hypoallergenic formula.

If your child reacts to your breast milk, the doctor may recommend you switch to a formula temporarily. Then, while pumping to maintain your supply, you can work with your child’s doctor to determine the exact allergy so that you can remove it from your diet and begin breastfeeding again.

If your child only reacts to one or two foods, they can simply avoid eating them. Ultimately, the best course of management and treatment for FPIES is to avoid the allergen altogether.

What Is the Prognosis for FPIES?

It may take several weeks or months to get a diagnosis of FPIES. Then, you will have to change your child’s lifestyle to meet the new restrictions that come with the diagnosis.

Fortunately, FPIES is not a lifelong condition. In fact, according to the ACAAI, most children will outgrow FPIES by age 3 or 4.

Once the doctor believes your child has outgrown their allergy, they will work with you to begin slowly introducing the trigger foods back into your child’s diet. They may also recommend you work with a dietitian experienced in working with those who have allergies. Your child’s doctor may want you to do food exposure tests in their office, where your child can be monitored. Once the doctor is satisfied that the trigger no longer causes an allergic reaction, you may begin feeding your child these foods again.

Unfortunately, some children may live with the condition beyond their earliest years. Some children with FPIES will deal with it into their adolescence and beyond. Thankfully, proper diet and FPIES control can help your child grow and thrive, despite the condition.

Speak with Your Doctor

when to see a doctor

If your child shows signs of FPIES, make an appointment to speak with your doctor. Identify the signs and symptoms your child experiences and when they occur. Testing for FPIES is limited and not very certain, so your child’s doctor may conduct several tests to eliminate other conditions. After those conditions are ruled out, your doctor may give an FPIES diagnosis. Together, you can begin developing ways to help your child live and cope with the new diagnosis.

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