Information packs available to download

What is food allergy?

What is FPIES?

What are the symptoms of FPIES?

Which foods cause FPIES reactions?

How is FPIES diagnosed?

I think my child has FPIES, what now?

How is an FPIES reaction treated?



Q. What is FPIES?

A. FPIES is a delayed (non IgE mediated) food allergy which leads to repeated vomiting and other gastrointestinal symptoms 1-6 hours after a problem food (or formula) is eaten.


Q. What are the symptoms of FPIES?

A. The most common symptom is vomiting. The vomiting seen with FPIES reactions is usually quite dramatic, with babies typically vomiting multiple times. Lethargy is commonly seen but in milder cases may be mistaken for 'just sleeping it off'. In more severe cases the child may appear to be 'passed out' or non responsive. Other symptoms which may be seen in some children include pale grey or blue appearance, diarrhoea (with or without blood) and abdominal pain.


Q. How is FPIES diagnosed?

A. FPIES is diagnosed by a typical clinical history, which includes profuse vomiting within 4 hours after a certain food is given on more than one occasion (this is to rule out gastroenteritis). Removal of the offending food brings resolution of the symptoms. Other conditions such as immediate (IgE mediated) food allergy, Eosinophilic Oesophagitis (EoE) and blood infection (sepsis) may need to be ruled out first.


Q. What age does FPIES typically first present?

A. FPIES presents usually in early infancy, either with the introduction of cow’s milk formula or when introduction of solids occur.


Q. My baby did not go into shock/ we did not go to hospital can it still be FPIES?

A. Yes, only 15% of babies go into shock, many recover at home with oral fluids


Q. My baby does not have any diarrhoea after a reaction, can it still be fpies?

A.  Yes, only 24% of babies have diarrhoea with reactions


Q. My baby has never had a severe vomiting reaction, just smaller amounts of vomit or diarrhoea. Is this called chronic FPIES?

A.  In the UK if there is a clear association with a food then this is likely to be diagnosed as a non-IgE mediated food allergy. If the diagnosis is unclear other diagnoses may need to be considered. In other countries these symptoms may be given the name chronic FPIES, however here in the UK, most doctors will require there to be a history of profuse vomiting as described above to make a diagnosis of FPIES. 


Q. Can babies react to breastmilk?

A. There are very few studies on FPIES reactions via breast milk. Those that have been done show that profuse vomiting reactions to breast milk in children with FPIES are rare. However, as a small amount of allergen may be transferred through the breast milk, it is possible for a breastfed child with FPIES to have symptoms of intermittent vomiting or reflux, diarrhoea, constipation, blood/mucus in the stools and poor weight gain as a result of these allergens. In these cases the allergen should ideally be identified and removed from the mother's diet if possible.

Some children have no symptoms via breast milk, in these cases the allergen does not need to be excluded from the mother's diet.  We would welcome more studies on the severity of symptoms in breastfed children with FPIES to allergens in their mother's diet.


Remember it is important that you seek professional advice before you take out foods out of your diet as you will need help with this and supplementation.


Q. Which foods cause FPIES?

A. The most common foods that cause FPIES are cow’s milk, soya, rice and grains like oat and barley. However there are case reports of FPIES to a number of fruits and vegetables, such as bananas, peas, beans and sweet potato and also meats such as beef and chicken. In theory you can have FPIES to any food, therefore it is important to have professional help in the management of your child's diet. It is also important to remember that each child is individual and most children will only have FPIES reactions to one or two foods.


Q. How is FPIES treated?

A. FPIES is treated by removing the problem food(s) or cow’s milk/ soya formula from the diet.

For babies who are exclusively breastfed and experiencing symptoms, this may mean removing foods from mums diet. Advice should always be sought from a healthcare professional before removing major food groups such as dairy from the diet to prevent vitamin/ mineral deficiencies.

For formula fed infants reacting to cow's milk formula or soya formula, a hypoallergenic formula is required. There are two types of hypoallergenic formulas, extensively hydrolysed (i.e. Nutramigen Lipil, Althera, Aptamil Pepti) or amino acid formulas (Neocate LCP, Pureamino, Alfamino). It is important that the right formula is chosen as they have different characteristics, hence professional advice is required.

If you are breastfeeding it may be advisable to continue pumping whilst trialing formula in the rare case that your child does not tolerate any of the formulas available.


For babies who are weaning onto solids, foods should be introduced slowly, in small volumes, one at a time for a 3-7 day period, under supervision of a dietitian. Any food which does not cause symptoms can be continued whilst new foods are introduced. There is very little evidence on the best way to introduce solids in children with FPIES, you may therefore find this guidance on weaning useful. Click here. For further hints and tips see our Food Trials page.


Q. My Baby is having an acute reaction and vomiting profusely, what should i do?

A. Seek medical advice immediately. If your baby is lethargic, floppy, pale or blue DIAL 999.

If your child's reaction is less severe or they appear to be recovering it is still best to have your baby checked by a doctor so please contact your GP surgery or 111 for more advice.

It is useful to have a copy of the A&E letter in the emergency plan section or the letter provided by your consultant already printed and in a convenient place such as your babies changing bag, should you ever need to go to hospital.


Q. The doctors at the hospital did blood tests that showed infection, does this mean the illness was not FPIES?

A. During an FPIES reaction there is a marked increase in white blood cells in the bloodstream, this is also a common sign of infection, so it is very hard to distinguish between the two on blood tests. Babies with FPIES will recover rapidly within a few hours once replacement fluids are given. Antibiotics are not required but some doctors may wish to give them just in case. As sepsis (blood infection) can kill.


Q. What treatment will the doctors at the hospital give?

A. The treatment is symptomatic. Depending on how ill your baby is, doctors will either give fluids by mouth (if vomiting has stopped) or intravenous fluids. Steroids are sometimes given because the reaction is believed to be due to a T cell response. Adrenalin/ epinephrine is not recommended unless there are also symptoms of an IgE mediated allergy. As stated above the doctor will need to rule out other conditions such as poison ingestion or infection. They may want to give antibiotics if they think the symptoms may be due to infection.

Two recent studies have shown that an anti-sickness drug called Ondansetron, Zofran may help to reduce the severity of reactions, so this may be something your doctor may want to consider. More information regarding this can be found on our Info for HCP's page.


Q. How many triggers can a child have?

A. There are many children with only one or two trigger foods which cause FPIES reactions. However Up to 5% of children react to more than 6 or 7 foods. Some children with FPIES will also have IgE mediated and non-IgE mediated allergies to other foods.

For those children who seem to have some degree of symptoms to many other foods. You and your medical team may need to rule out some other causes which are sometimes seen in babies in combination with FPIES.


These include:

Trialling a new food too soon after a previous reaction. This can cause symptoms if the gut is not fully healed at the time the new food is started.


Reactions through breast milk. If your child is still breastfed and is having reactions to many foods it may be worth considering that something within your own diet may be causing ongoing chronic inflammation in your child, resulting in symptoms which you interpret as being due to solid foods. Remember it is important though that you seek professional advice before you take out foods out of your diet as you will need help with this and supplementation.


Chronic gut inflammation. Some babies and children with chronic gut inflammation may benefit from medications to calm the gut and allow the introduction of food without symptoms. If you require further information speak to your medical team.


Eosinophilic oesophagitis  is an increasingly common (but still rare) disease in which a type of white blood cell, the eosinophil, causes injury and inflammation to the oesophagus (the tube that connects the mouth to the stomach). Info here

This list is not extensive and there are other conditions that may also need to considered on an individual basis.


Q. Will my baby grow out of this condition?

A. Almost certainly yes, the majority of children outgrow their FPIES reactions by the time they are three years old, with the remainder typically outgrowing them by age 5. There are however some older children and teenagers who still have FPIES. FPIES reactions to fish and shellfish have been reported in adults.


Studies have shown children with positive blood/ skin prick tests to their FPIES trigger(s) (this is called Atypical FPIES) take longer to outgrow their problem foods.


Q. How will i know when my child has outgrown it?

A. For foods that cause FPIES reactions your consultant should arrange a re-trial in hospital, usually 12-24 months after the last reaction. An intravenous cannula may be placed and a skin prick test to the food will be performed (as some FPIES triggers can become IgE allergies over time) before feeding your child the food. Your child will then be observed over the course of the day for any symptoms.

For foods that caused a milder reaction, re-introduction may be done at home following the advice of your consultant or dietitian. Further information on Oral food challenges can be found here



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