Babies can be unsettled for many reasons and it can sometimes take time and effort to work out the cause. Our page The Unhappy Breastfed Baby can help you determine whether your baby’s behaviour is due to something other than an allergy.
But when you have ruled out most of the obvious causes and your baby is still, unhappy, colicky, experiencing dry and itchy skin or passing mucousy stools you may wonder whether they could be reacting to something in their diet or environment, or something in your own diet.
Certain medical conditions can have symptoms similar to those of an allergic reaction. It may be wise to rule these out before deciding whether a baby’s symptoms are due to an allergy or food intolerance.
A baby’s immune system is immature at birth.
Colostrum, or early milk, is rich in antibodies, particularly secretory IgA (SIgA), which provide a protective coating inside a baby’s intestines1. Mature breastmilk continues to provide protection, helping to prevent potential allergens from reaching a baby’s blood.
Exclusive breastfeeding generally helps to protect against allergy but it may still occur.
If any immediate family member ( siblings or parents) has an allergy eczema, hay fever or asthma, it makes it more likely that the baby could develop allergies2.
A food intolerance does not involve an allergic reaction but can cause similar symptoms. It occurs when a baby has difficulty digesting a particular food. You may not need to stop giving your baby a food to which he is intolerant—reducing the amount may be enough.
A food allergy occurs when a baby has an immune response to specific foods. There are two types of food allergy reactions; immediate and delayed. A baby can have either or both3.
Immediate reactions are also called IgE-mediated alllergies. This is because the baby’s immune system creates specific IgE antibodies to a certain food. If a baby is given the specific food they are allergic to, the IgE antibodies will recognise it and cause the rapid release of chemicals, including histamine, that trigger inflammation and allergic symptoms. Symptoms appear within minutes, or up to 2 hours after eating the food responsible3.
Delayed reactions are called non-IgE mediated allergies because they are not controlled by IgE. Instead it is believed such reactions are regulated by immune cells. Symptoms appear 4-72 hours after eating the food3.
It is wise to see your GP or health visitor if your baby is showing signs of allergy, but some symptoms are more worrying than others. Seek immediate medical help if your baby has signs of an anaphylactic reaction: sudden onset of breathing difficulties, swelling, or collapse, with or without a rash, after physical contact or eating a particular food.
Food allergy symptoms occur in several different body systems; the tummy, airways and skin. An Allergic baby will usually have symptoms in more than one body system, but need not experience all the symptoms to indicate allergy. Many of the following allergy symptoms can also occur in normally developing children for other reasons.
|IgE mediated symptoms3
|Non-IgE mediated symptoms3
|Immediate: within minutes or up to 2 hours
within 4–72 hours
|Baby hungry for the breast but pulls away after a minute or two, arching the back and screaming*
Swelling, usually around the lips, face and eyes
Colicky tummy pain***
Loose or frequent poos
Blood or mucus in poo
Food refusal or aversion
Inflammation in the nappy area**
|Cough, chest tightness, wheeze, noisy breathing, trouble breathing
Itchy nose, sneezing, runny nose, nasal congestion, conjunctivitis
|Cough, chest tightness, wheeze, noisy breathing, trouble breathing
|Anaphylaxis: sudden onset of breathing difficulties, swelling, or collapse with or without a rash
|Reduced growth, along with one
or more tummy symptoms above
|*This may also be caused by a fast let-down. See Too Much Milk and Oversupply for
more information if you think that this may apply to you.
**Inflammation appears red on lighter skin, and darker brown, purple or grey on darker skin.
***Colic is defined as repeated episodes of excessive and inconsolable crying in an infant that
otherwise appears to be healthy and thriving.
An irritant is something that causes damage to the skin. Eczema (also known as dermatitis) and dry skin rashes can be caused by mild irritants such as bubble bath, baby wipes, skin cream, fabric conditioner or laundry detergent4. Many mothers find avoiding unnecessary products or using a different product improves things. Reading packaging can help avoid problems with common irritants such as lanolin and perfumes. Use fragrance-free products whenever possible. Be aware that herbals can also be allergenic and irritant – being natural does not necessarily mean a product is any less irritating. Hay fever symptoms and other ear, nose and throat symptoms can be caused by spring and summer pollens and other airborne allergens such as dust.
Identifying the problem food
If your baby is having only your milk
Food allergens in the mother’s diet can pass through into the breastmilk so a breastfed baby can have an allergic response or intolerance to something in the mother’s diet.
- Are you taking any laxatives, medicines, vitamins, iron tablets or other supplements?
- Do you drink lots of caffeinated drinks? Coffee, cola, tea and some pain relievers, cold remedies, weight control aids and diuretics contain caffeine. Chocolate contains a substance called theobromine that can have a similar effect to caffeine if you eat a lot.
- Have you recently eaten a new food or any particular food in large amounts?
- Are there any foods that you don’t like but have decided to eat during pregnancy or breastfeeding because you think they will be good for you and your baby?
- Are there foods that you crave? What foods do you snack on when you have a bad day?
Depending on how sensitive your baby is, removing or cutting down on the offending items in your diet may well solve the problem.
If your baby is also having infant formula or solids
The majority of babies don’t need anything other than mother’s milk before about six months — no infant formula, drinks or solids. Babies who have started solids can be sensitive to certain common foods until they are a little older.
- Could your baby be reacting to the drinks or solid foods he is having?
- Is he on any medication or vitamin supplements?
- Could he be receiving other drinks such as infant formula or juice, or solid food, from anyone else without your knowledge?
- Infant formula or follow-on formula is usually cow’s milk-based and a common, avoidable cause of allergy. Babies do not need follow-on formula at all.
Removing the offending food from your baby’s diet for now should solve the problem; they may be able to tolerate it in a few months time. If you think your baby may be reacting to a prescribed medication that they have to take, speak to your doctor, who may be able to prescribe an alternative.
Common problem foods5
Common problem foods which may be eaten by a baby or a breastfeeding mother include:
- Milk and other dairy products such as butter, yoghurt, cheese, whey, casein, caseinate, lactose
- Sesame seeds (in tahini and hummus)
- Lupin/lentils (including chickpeas which are in hummus)
- Shellfish; crustaceans (e.g. crab, lobster, crayfish, shrimp, prawn), molluscs (e.g. mussels, oysters, squid)
- Fenugreek is closely related to peanuts
- Tree nuts (almonds, hazelnuts, walnuts, cashews, etc.)
- Celery and celeriac
Common foods that can be involved in intolerance or irritation but not usually allergy:
- Sulphur dioxide and sulphites, benzoates, glutamate, salicylates, dietary amines
- Citrus fruits, strawberries, tomatoes
- Certain additives, artificial colourings, flavourings and preservatives
These can turn up in the most unexpected places so do check everything consumed including drinks and medicines. For example, some juice drinks contain milk, and wine can contain milk, egg or sulphites.
Cutting out suspected foods
If your baby is exclusively breastfed, you may need to follow an elimination – reintroduction diet. It can help to keep a food and symptom diary.
When eliminating major food groups take care to ensure you continue to eat a healthy and balanced diet. Your GP may be able to refer you to a dietician if you wish.
Only cut out one food at a time and allow 2–4 weeks to see if your baby’s symptoms improve. If there is no improvement in this time, then the food is unlikely to be the culprit and can be reintroduced3. Consider cutting out a different food.
If symptoms do improve, reintroduce the food slowly to confirm the food allergy. However, if your baby has previously experienced a severe or immediate reaction, ask your GP for specialist support before reintroducing the food.
Note: Usually a cow’s milk protein allergy (CMPA) predicts an allergy to other animal milks (e.g. goat or sheep milk), and in some cases soya. If you plan to cut out dairy you may wish to cut out other animal milks and soya at the same time, then reintroduce them each individually.
Seek immediate medical help if your baby has shown anaphylactic signs, such as a rapidly developing rash, breathing difficulties, or swelling.
A note on eczema
Elimination – reintroduction diets should not be done due to the presence of eczema alone.
Some children who have a food allergy do have eczema, but most children who have eczema do not have a food allergy. If the only symptom is eczema it is unlikely to be caused by a food allergy. It is worth noting that frequently eating a particular food may mean a baby learns to tolerate it. If the food is stopped, for example during an elimination diet, there is a risk that tolerance may stop and an IgE mediated allergy (including possible anaphylaxis) can form. If you think your baby’s eczema is due to a food allergy it is best to speak with your GP about allergy testing or to get referred to an allergy specialist6.
Introducing solid foods
Human milk contains tiny traces of whatever foods a mother herself has been eating. This is the ideal way to prepare a baby gently for the eventual introduction of solids. The best foods for your baby are usually healthy foods selected from your diet. Solids can be introduced when your baby can sit up (with or without support) and starts reaching out for the food on your plate. For more information, see Starting Solid Food.
If your baby is under the care of a paediatrician for allergies, talk to your specialist team about how to introduce specific allergenic foods.
Body tolerance levels can change
Being allergic or intolerant to something means that your body is sensitised to it, but the symptoms you display may vary in each particular instance; sometimes you may not display any symptoms. Your body’s allergen tolerance level changes based on many factors including stress and your general health, so its ability to react to immune threats also varies. If your immune system is affected by more stressors than usual, you may show symptoms of an allergy/intolerance more readily.
It can be quite an effort to be an allergy detective with a fussy baby on your hands, so seek information and support. The good news is that small changes to your diet could make a big difference to a baby with a food allergy or intolerance.
An LLL Leader can help you determine the most likely cause of your baby’s symptoms. Local LLL groups are great for practical and moral support and you may find others there who have had similar experiences. Your GP or health visitor can help diagnose food allergy and refer you to specialist services for testing and advice.
Did you know?
- If a baby reacts when their mother drinks milk or has dairy products, this is a sensitivity to cow’s milk protein, not lactose intolerance.
- Most infant formulas contain cow’s milk, often referred to as whey based or casein based.
- Soya, the basis of some infant formulas, is also a common allergen.
- Infant formula may contain fish oils and vegetable oils (e.g. palm, rapeseed, coconut, sunflower).
- Medicines and supplements can contain other ingredients that are potentially allergenic.
- If you or a member of your immediate family has an allergy or intolerance, your baby is more likely to have one too1.
Q. Do I have to give up breastfeeding if my baby is allergic to something in my milk?
A. No; eliminating the offending food from your diet will remove the allergen from your breast milk enabling you to continue breastfeeding if you wish to. See section Cutting out suspected food.
Q. Will my baby outgrow his food allergy?
A. Possibly; some children do, some do not. Children are most likely to grow out of cows’ milk, egg and soy allergies.
Q. I thought I was not meant to feed my baby egg/peanut/etc. until they were over 1 year old?
A. This was old advice. Recent research shows introducing allergenic foods from around 6 months old may help the baby to learn to tolerate the food. Introducing the food later can make it more likely that the baby will develop an allergy to the food.
Q. What’s the difference between cow’s milk protein allergy (CMPA) and lactose intolerance?
A. True lactose intolerance (reduced capacity to digest lactose) is very rare in babies and is diagnosed within days of birth. Temporary lactose intolerance or lactose overload (too much lactose for the baby to digest) can cause tummy symptoms similar to an allergy. Lactose is produced in the breast, regardless of the mother’s diet. Seek support if you suspect your baby has symptoms of lactose overload. CMPA is an immune reaction and can cause symptoms in many body systems. Breastfeeding mothers of children with CMPA generally need to exclude all cow’s milk protein from their diet – including milk, cheese, yogurt etc. See section Cutting out suspected food.
Q. Should I avoid eating a food my baby is allergic to if I become pregnant again?
A. No; as long as you are not allergic to it and it is not one the foods you usually need to avoid in pregnancy (such as undercooked meat) eating a particular food in pregnancy has no effect on the development of allergy.
Q. Is my baby allergic to a food because I ate it whilst pregnant?
A. No; eating a particular food in pregnancy has no effect on the development of allergy.
Q. If I have another baby will it develop allergies too?
A. Possibly; if you have a sibling with allergies you are more likely to be genetically predisposed to develop allergies. However, having an older sibling decreases the risk of developing allergy.
Written by Sue Cardus, Robyn Halliday and mothers of La Leche League Great Britain
- Andreas, N., Kampmann, B., Le-Doare, K. Human Breast Milk: A review on its composition and bioactivity. Early Human Development, 2015; 91 (11): 629-635.
- Muraro, A et al. EACCI Food Allergy and Anaphylaxis Guidelines. Primary prevention of food allergy. Allergy, 2014;69(5):590-601.
- NICE Guideline [CG116]. Food allergy in under 19s: assessment and diagnosis, 23rd February 2011, https://www.nice.org.uk/guidance/cg116 (accessed 26th Jul 2020).
- NHS. Contact dermatitis, https://www.nhs.uk/conditions/contact-dermatitis/causes/ (accessed 26th Jul 2020).
- Muraro, A et al. EAACI Food Allergy and Anaphylaxis Guidelines. Diagnosis and management of food allergy. Allergy, 2014; 69 (8): 1008-25.
- Young, M. Editorial: Elimination Diets in Eczema—A Cautionary Tale. JACI: In Practice, 2016; https://www.jaci-inpractice.org/article/S2213-2198(15)00573-5/pdf
The Womanly Art of Breastfeeding. LLLI. London: Pinter & Martin, 2010.
BREASTFEEDING ANSWERS – A GUIDE
FOR HELPING FAMILIES: SECOND EDITION.. Mohrbacher, N. Nancy Mohrbacher Solutions inc., 2020.
MILK MATTERS: INFANT FEEDING AND IMMUNE DISORDER. Minchin, M. Geelong: Alma Publications, 2015.
BREASTFEEDING WORKS! EVEN WITH ALLERGIES. Noble, R. Brisbane: Complete Publishing, 2017.
Is My Baby Getting Enough Milk?
My Baby Won’t Breastfeed
Rhythms and Routines
Safer Sleep & the Breastfed Baby
Starting Solid Food
Toddlers and Food
The Unhappy Breastfed Baby
Too Much milk
Thrush and Breastfeeding
Unicef Research on Allergies
NICE Guideline [CG116]. Food allergy in under
19s: Assessment and Diagnosis
GP Infant Feeding Network: Cow’s Milk Allergy
National Eczema Society
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