Q&A with Dr Adam Fox about dairy allergy and lactose intolerance
Consultant paediatric allergist and Lactofree expert Dr Adam Fox joined us in May 2011 to answer your questions on all things related to dairy allergies and lactose intolerance.
Dr Fox trained in paediatrics and paediatric allergy in some of the country's leading teaching hospitals, including London's Great Ormond St, St Mary's and Royal Free hospitals. He is now consultant paediatric allergist at Guy's & St Thomas' Hospitals as well as honorary senior lecturer in paediatric allergy at King's College London.
Q. MoreBeta: There seems to be some confusion in people's minds about lactose intolerance and general dairy intolerance, but there is a huge difference. For instance, I am a coeliac and as a result am intolerant to lactose, which is the naturally occurring sugar in milk. I am not intolerant to milk protein, which is what many of you appear to be talking about when you say you or your child are dairy intolerant. An allergy to cows' milk protein is often confused with lactose intolerance, but they are quite different things.
I can drink Lactofree milk because it is ordinary cow's milk that has been pre-treated with an enzyme called lactase, which breaks down the lactose. A baby or child or adult who is intolerant to milk protein could not drink Lactofree milk as it still has milk protein in it.
A. Adam: Thanks – you are absolutely spot on. Lactose intolerance is a difficulty digesting lactose, the sugar (carbohydrate) found in milk. It can cause uncomfortable symptoms but it's not life-threatening.
Lactose intolerance shouldn't be confused with milk allergy, which is your immune system's over-reaction to one or more of the proteins found in milk. Milk allergy can be extremely severe and in some cases can cause life-threatening anaphylaxis.
However, you can also get delayed allergies to milk, which are still caused by the protein in milk but involve a slower acting part of the immune system. These reactions can cause chronic eczema or diarrhoea, reflux or abdominal pain. Our understanding and recognition of these delayed types of allergy has not been great over the past few years and they have often been referred to as cow's milk intolerance (hence the confusion with lactose intolerance, although they are very different conditions and we try to avoid this term now).
Lactose intolerance doesn't involve the immune system so, while it can cause a great deal of discomfort, it won't produce a sudden or dangerous reaction. Unfortunately, many people, doctors included, get these very different conditions confused. Newspaper and magazine articles sometimes even use the terms interchangeably, so be very careful how you interpret them.
Q. Jackie83: My son was born four weeks early and seemed to be very unsettled and uncomfortable after breastfeeding. He had cramping and very bad wind that nothing seemed to help, and feeding times were very hard and emotionally draining, so after six weeks I finally switched to formula.
I tried a colic treatment, after reading that premature babies can react to lactose badly due to their immature digestive system and there seemed to be a big difference. But how do I wean him off? Every time I've started reducing the amount he seems very uncomfortable again. However, he's also showing symptoms of silent reflux so the GP gave us infant Gaviscon to try and that has made things better.
How do I know if he definitely has a lactose intolerance rather than it just being something else like reflux? Will his system learn to cope if I persevere with weaning him off it and get used to lactose, or is it better to just keep up with the Colief and keep him off lactose completely?
A. Adam: Lactose intolerance is very rarely a cause of colic and, if this is the case, rather than using Colief, just switching to a completely lactose-free infant formula would completely resolve the problem. I would chat to your doctor about this, as there may be a delayed type milk allergy (if you are breast feeding, try cutting milk out of your own diet for a couple of weeks) or simply undertreated reflux.
Q. InAStateOfReflux: I have read that this transient lactose intolerance can be a common cause of 'colic' in babies. It could end up being a big barrier to breastfeeding if it is not recognised and treated correctly, I would imagine, as it was to me.
Why can't doctors test for this? And why do GPs not recognise the problem and take it seriously? Or, if they do not have the specialist knowledge, why do they not make appropriate referrals more readily? If lactose intolerance is common, then it should be recognised so that families can be supported in continuing to breastfeed, and reassured that in many cases babies can grow out of it (although I know this is not always the case).
A. Adam: I am not convinced by this at all. Our understanding of colic is poor and there is no good evidence that putting colicky infants onto lactose-free infant formulas is helpful in a significant number of kids. There are a group of kids (with clues your doctor should ask you about) who may benefit from a change in the mum's diet (to exclude milk) or a formula change, if bottlefed, if there is a delayed type milk allergy, while in others anti-reflux may help, but in the majority neither do. Each infant needs thinking about individually, as there is no single cause for 'colic', although it's interesting that colic is very rare in certain cultures, especially those where babies are swaddled.
Q. BlameItOnTheBogey: Dr Fox, my daughter has an allergy to cow's milk protein. She's only 18 months, and was diagnosed at six months after a violent reaction to the first food I gave her (porridge made with milk). So far, she has been tested for everything going and has no other known allergies. Is there a critical period during which children develop allergies, or could she suddenly react to something which she has previously been able to eat? She's showing all the signs of growing out of her milk allergy and I'm really hopeful that that might mean she is allergy free one day but wonder if that is unrealistic?
A. Adam: Most immediate type food allergies develop in infancy, although these can develop later even after the food has previously been tolerated, but that is rare. Most kids do outgrow milk allergy, although often later than we previously thought. The best study suggests on average by eight to 10 years, but some may outgrow it much earlier and others never do.
Q. BalloonSlayer: Is cow's milk protein always present in a mother's breastmilk if she consumes cow's milk? I ask because I knew my oldest son was allergic to milk (and soya), and his severe eczema improved hugely when I cut out soya and milk from his diet, but I didn't exclude them from mine while breastfeeding him.
When I tried him with cow's milk (on a dietitian's advice) at a year old, he had an extremely serious reaction, after which he had to carry an EpiPen. His allergy to milk had obviously got a lot worse in the seven or eight months since he last had cow's milk. However, he went on to always react to the smallest trace of milk contamination in any food he was given, yet he would never have a reaction to breast milk. Why is that?
A. Adam: Some milk proteins in a mum's diet will get through to the breast milk and while some infants do react to this, others don't. This relates either to the sensitivity of the infant to milk – those who are less sensitive tend not to react - but also to the way the milk is presented to the baby, for instance along with other protective antibodies in the breastmilk, which may minimise the effect they have. Alternatively, the specific milk protein your child is sensitive to may be one that gets broken down or reduced as the breastmilk is formed.
Q. Mintyneb: My four-year-old daughter is allergic to cow's milk protein (CMP). It presented itself as projectile vomiting and extreme listlessness after being given small amounts of formula milk as a small baby and then hives on her face after contact with cheese/milk while weaning her.
At the age of one, she had her first RAST test with a score of two. Last year (when she was three years old) it had risen to eight and then in February this year it had gone up to 24. Having been told that it was quite likely that she would outgrow the allergy before starting school, I am beginning to wonder if she will ever outgrow it.
Will it continue to get worse? She had an accidental exposure to ice-cream last December where her fingertip touched a dessert and despite having wiped it clean she then rubbed her face and a trace, that must have been left under her fingernail, caused her to have hives all the way across her cheek and forehead and her eye to swell up. Two doses of Piriton finally got her eye back to normal. but I'm worried that this might not be enough if she is accidentally exposed to CMP in the future.
Finally, is there anything to be gained by seeing an allergy specialist? My daughter also has cystic fibrosis so we see a hospital dietician every two months, but allergies are obviously not their specialty so I'm wondering if there is anything we might be missing out on?
A. Adam: It's easy to fall in to the trap that the higher numbers on testing mean the allergy is more severe but this is not the case. The size of the allergy tests relates to the likelihood that you are allergic to that food, not severity of a reaction.
Severity of reaction tends to relate to loads of factors, most importantly your state of health when you have the reaction (which a test can't predict).
The idea that reactions get worse on each exposure is a myth. The most severe food allergic reactions occur in those who all have asthma or have had anaphylaxis (a severe reaction involving difficulty breathing or a drop in blood pressure) – these kids should definitely be carrying adrenaline injectors around.
If you feel you want to know more about the allergies then seeing an allergist should be helpful. As mentioned in one of my other responses, most kids do outgrow milk allergy although often later than we previously thought. The best study suggests on average by eight to 10 years but some may outgrow in much earlier and others never do.
Q. Nanatothree: My three-year-old grandson was diagnosed with cow's milk protein allergy when he was 10 months old, after symptoms that seemed to be present from birth. He was dairy-free for a year and then tested with skin prick tests and RAST test. We have been told he has an IgE result of 491 and that this is a severe allergy to CMP so he is still dairy-free now. He is a very poor sleeper and will wake up scratching at his body. My question is, should he be eating beef? As this has been mentioned by a friend and I must admit we didn't think to omit this from his diet. Is he likely to outgrow it?
A. Adam: Yes, but you may have to be patient. Recent research has suggested we had been a little optimistic about how early milk allergy was outgrown. The high total IgE level you mention does not tell you anything about the severity of the milk allergy, just that he is an allergic child. Unfortunately, the allergy tests do not tell us about the severity of reactions, which are unpredictable.
Regarding beef: this is an uncommon allergen and very seldom a problem in milk allergic problems, but if you suspect he has had a reaction you could ask your doctor for an allergy test.
Q. Rainbowrain: My son was breast-fed and formula-fed when he was born, and during this time we noticed a lot of smelly farts and bloated tummy but were told this was normal. Four months later he was in hospital due to bloody diarrhoea, and although we were never given a conclusive answer as to what this may be due to, we suspected that it was cow's milk protein intolerance. Since then it's just been breast milk and dairy-free food.
I give him the odd yoghurt to try, which does cause him to resume farting a bit, something which hasn't happened since the hospital visit. I'm not sure if this is due to intolerance. What I should do next? He is one now, so do I start introducing dairy or not? Would it help build tolerance? I've been to GPs but don't seem to get any advice on it.
A. Adam: It may be that he had a delayed milk allergy (often referred to as a milk intolerance) and these can be outgrown early (by the age of one). Either he is or isn't still allergic and reintroducing is probably the only way you can find out. I would suggest you go back and discuss this with your doctor, according to the individual circumstances. There are now guidelines from NICE on this to help guide his decision-making.
Q. Misssic: Our son has 'off the scale' allergy to milk (EpiPens always at the ready) and I just wondered is the statistic that 80% outgrow it by the age of five is correct? I am intrigued how you can outgrow an allergy? Is it genetic and does this mean if we have another child there is a good chance he or she will have allergies - no-one on my side of the family, but my husband's mother/family have eczema.
A. Adam: This statistic is slightly outdated and more recent studies suggest that 50% of children will outgrow an allergy between the ages of eight and 12. An allergy to milk, eggs, wheat and soya can be outgrown while it is less common for a nut or fish allergy to simply go away. However, we still don't fully understand why some allergies disappear and others don't.
A propensity to allergies tends to develop due to genetics, but an allergy to something specific (like nuts) is not inherited. Rather, if both parents have the allergic tendency (meaning they have asthma, eczema, hayfever or a food allergy) then the child has an 80% chance of also having some form of allergy. However, the exact allergy or allergies that the child develops seems to also depend on environmental factors. But unfortunately this means that if you have one child with allergies then there is a good chance that your other children will also have an allergic tendency.
Q. Libelulle: My three-year-old daughter is allergic to dairy, diagnosed at eight months old. At first, she looked to be gradually outgrowing her allergy - she could tolerate small amounts of cooked milk in baking, and her reactions became less severe (sneezing and streaming nose rather than hives and lip swelling). However, in the past six months or so her allergy seems to have worsened again - even some foods which only have a 'may contain traces of dairy' warning now provoke consistent and immediate complaints that they make her mouth and throat hurt.
Am I right in now feeling gloomily pessimistic about her chances of outgrowing her allergy, and feel that the fact that they appear to have worsened is presumably a bad sign? We now avoid all dairy like the plague, but I'd also be interested to know how long we now wait until giving her another challenge. In the past, we have received conflicting medical advice about whether she should be 100% dairy free, or whether we should be 'inducing tolerance' and giving her as much dairy as she is able to consume without reaction. What is your view on this?
A. Adam: If she is allergic (sounds like she still is) there is no evidence that continuing to try to get her to eat some, causing reactions, will in anyway help her outgrow this. Trying to 'desensitise' at home is not a good idea as it can cause very severe reactions. Many milk allergic kids will tolerate baked milk, eg in biscuits, and if they can then including this in their diet is fine but probably doesn't help them outgrow the allergy quicker.
Q. Tak1ngchances: I suffered with severe allergies to dairy products when I was a child (until I was seven). I am wondering if this is a hereditary thing and if I am likely to pass the allergy to my child. My husband and I are currently trying to conceive our first. Neither of my parents have any food allergies.
A. Adam: You can pass on an allergic tendency but not a specific allergy. If your husband has any allergic conditions too (eg eczema, food allergy, hayfever) the chances of your child having an allergic tendency are about 80%. Exclusive breast feeding for four to six months is the only thing really shown to help reduce the risk of allergy problems.
Q. Pancakeflipper: Could you please explain how a milk intolerance is 'tested'? Are there many 'medical' tests to do so, or do you just wait for reactions like face swelling, vomit and diarrhoea ? Ours was 'trial and error' with foods and it was a miserable experience.
A. Adam: Immediate milk allergies are tested for with either a blood test (called specific IgE) or a skin-prick test. These are very reliable when interpreted by an experienced doctor. Delayed milk allergies (referred to sometimes as milk intolerance) does not have good tests so, when suspected, diagnosis is made by seeing if symptoms improve when the food is excluded and return when it is reintroduced.
Be very wary of tests available on the web or high street – there are lots of them and they have no benefit for diagnosing either immediate or delayed type food allergy.
Q. Prairiedog: I have a two year -old who has been tested for allergies and appears to have none. However, she has almost constant diarrhoea and I think it is milk, soya and egg which cause this. Is there any way to test for other things she may be intolerant to? Will strictly excluding all of these from her diet help her to get over the intolerance with time?
A. Adam: Allergy tests only show up immediate type allergies, not delayed ones, so the negative tests do not mean your child doesn't have allergies. Milk, egg, wheat and soy are the most likely causes and you will only know by cutting them out and then reintroducing them. I would advise you only do this together with your GP or a dietician being involved.
Q. ronshar: My main question is how on earth do I get my children to see an allergist? My GP surgery refuses to send any of my children to have allergy test. My oldest, 11, has a nut allergy, but to which one, and how severely, is a mystery so we live in fear! My second daughter, who is six, has a dairy allergy, which seems to be getting worse rather than better with age. Again, we don't know what she is allergic to so we avoid all dairy.
My son, who is two, has had problems from birth, which led me to cut all dairy from my diet as I was exclusively breastfeeding. He wouldn't tolerate Nutramigen (the special food for children with a cow's milk allergy or lactose intolerance). He is unable to tolerate anything with dairy in. He doesn't come out in hives, but it just goes straight through him - he ends up with extremely smelly, loose stools. But we don't go to the doctors because they are not interested in doing anything to help us. What can I do to try and find out what exactly is wrong with my children?
A. Adam: You really need to see a doctor with experience in paediatric allergy as I strongly suspect most of your questions could be answered. The new NICE guidance for GPs on food allergy is clear that children such as yours should be referred to a specialist, so please discuss this with your GP.
Q. Julezboo: My third son was born five weeks early. We had a hellish 12 weeks when he was finally diagnosed with a cow's milk protein allergy. I would like to know the best way to tackle weaning when the time comes. Do I need a referral to a dietician? My health visitor is not really around much. He is 16 weeks old now and I have read a number of people'se experience of early weaning helping reflux (which he also has). Would his early birth be to cause of this allergy? There are no other allergies in the family at all.
A. Adam: Prematurity is not a particular risk factor for food allergy. If he has a known milk allergy you should definitely be getting guidance from a dietician – you can ask your GP to refer to the community dietician if the hospital one isn't working out.
Q. Munkiii: My daughter is five-months-old and has been diagnosed with cow's milk allergy and as such is on Nutramigen. She also has very severe reflux and as such is on a high dose of the colic treatment Infacol (2.5ml before feeds) as well as ranitidine and carobel.
My question is really about weaning, we are due to see a dietician alongside her consultant but I wondered what your opinion was on how to challenge her with dairy and whether there are any other associated allergic reactions we should watch out for?
A. Adam: If she still has the ongoing symptoms you describe, I think you need advice as to whether you are on the correct formula. If the underlying problem is milk allergy, then it may be that the small amount of milk in Nutramigen is causing the persistent symptoms. Changing to a completely broken down formula (Neocate or Nutramigen AA) may well help, so please ask for advice on this from the dietician or doctor.
Q. dietstartstmoz: Our second son, who is almost four years old, was diagnosed with autism about two months ago now. He has always had very loose bowel movements, usually three or four times a day, and he has been tested for coeliac disease and was negative. I have been informed of the Sunderland test through Mumsnet, and have requested a pack but haven't sent a sample off yet. (It is a urine test that looks at the amount of peptides in the urine, costs £60 and is done by an autism research centre at Sunderland University.)
We know dairy-free diets can help lots of children with ASD, and we have cut down on the dairy and DS is now doing more solid bowel movements, but not quite there yet, some can still be very loose. Can we request any similar sort of testing on the NHS? Our doctor and paediatrician are not interested in testing further and we have not have a referral to a dietician.
A. Adam: The urinary peptide tests have not been scientifically proven to be useful and hence aren't available on the NHS. Some autistic children have very difficult problems with their stools and the most common problem is constipation (which can cause loose stools once the rectum is packed full of solid stools) but also sometimes inflammation in the gut, which can cause diarrhoea. Ideally, he should be assessed by a paediatrician with a gastro-interest to explore this.
Q. Sphil: My eight-year old son is autistic and has been on a dairy-free diet since he was five months old, following the advice of a dietician at the time, but I don't remember what specifically he was tested for, so I want to start reintroducing foods. He doesn't have immediate reactions, and is sensitive to eggs, nuts and gluten as well as soya. Reactions are increased eczema, loose bowels and an increase in autistic behaviours. What's the most reliable test?
A. Adam: There are unfortunately no reliable tests for this sort of problem, which is what makes it so tricky. Excluding and reintroducing one at a time with careful observation is the best there is at present.
Q. twolittlemonkeys: My son (aged five) is almost certainly autistic, probably Asperger's or on the high-functioning end of the spectrum (currently awaiting diagnosis) and has soiling problems. My GP shrugged this off when I took mu son recently. He doesn't have extreme reactions but having read that there are links between soiling and behaviour in autistic children and dairy, I am keen to find out if we can do any allergy testing. He loves yogurt, cheese, milk and hates most of the dairy-free alternatives.
Can he be tested to ascertain whether it is due to dairy intolerance? How long does a child need to have a dairy-free diet before noticing a difference with regard to these problems if dairy is the cause?
A. Adam: The most likely link here is constipation – very common in autistic kids and the most common cause of soiling. I would push for this to be considered before food exclusions.
Q. Likeaninjanow: I have a three-year old son who is allergic to many things, including cow's milk protein. It has been a difficult journey from when we started weaning at six months. We have only managed to get EpiPens after much fighting with health professionals, despite him being anaphylactic to numerous foods and us having to call 999 more than once.
It is now under control somewhat, but I'd really like to know what is being done in the way of research into the causes of such allergies. Can you elaborate on that? Is there funding available? I'm in Scotland, if that makes any difference. Currently, we see a paediatrician twice a year at best.
A. Adam: There is a lot going on – here and abroad. Check out the Anaphylaxis Campaign website and keep an eye out for a supplement on this topic in the Saturday Times.
Q. Bumperlicioso: My younger daughter appears to have some sort of dairy intolerance. She was being sick in the night from excess phlegm for about six weeks (since being weaned on to solids basically) and the only thing that stopped it was cutting out dairy (well, obvious dairy products). She is breastfed and as far as I know my milk isn't affecting her, it certainly isn't making her sick.
How do I get my GP to take me seriously? He doesn't seem to believe in dairy intolerance. How do I know if it is a cow's milk protein or lactose intolerance, and does that affect the things you can/can't have or whether they are cooked?
The other day I accidentally gave her an omelette with Parmesan and she came up in hives around her mouth, having previously had it at the beginning of weaning with no such effect. Does staying off dairy make the intolerance worse? I'm fed up with playing food detective and have no idea where to go from here in terms of reintroducing dairy to see if it has an effect. I wish my GP would be more helpful.
A. Adam: What you describe sounds much more like a milk allergy. I absolutely agree it should be a medical professional not yourself doing the detective work. I would advise you look at the parent's guide that accompanies the NICE Food Allergy guideline that came out in February 2011 (look on the NICE website). It goes through exactly what your GP should be asking about and testing for in this circumstance, and GPs do adhere to this.
Q. Serapisbey: My daughter is eight and has a dairy intolerance. It started once I'd stopped breastfeeding when she was two months. After one vaccine she developed a severe egg allergy - couldn't even touch an egg without her whole hand swelling up. I went down the homeopathy and restricted-diet route. On the whole it's been a successful journey. What has been a real help is the lactase enzyme tablets, which she takes before eating, and now she can have some cheese, chocolate, and even egg.
Why, oh why doesn't the pharmaceutical companies make these tablets to sell on prescription? They can really change a child's life and, coupled with a proactive, non-invasive approach, are surely cheaper? What are your views on this? Homeopathic remedies seem much cheaper and better than piriton as well. It makes me really cross that GPs don't, on the whole, take dietary issues very seriously.
A. Adam: As milk and egg allergies are often outgrown in early childhood, it is possible to think that treatments such as homeopathy have been successful, when in fact this is just the natural course of the disease. Medicines can only be licensed for prescriptions if they have undergone very stringent testing to prove they are both safe and effective.
Q. rockinhippy: Both me and my daughter are lactose intolerant, but neither of us were born that way, so I'm curious to know if there are any definitive links to either antibiotic use and lactose intolerance, or Helicobacter pylori infection and lactose intolerance?
I ask as I've noticed the beginning, and worsening of, my daughter's sensitivities, lactose included, after antibiotics, more than just the usual tummy problems associated with antibiotics. I've also recently been diagnosed with H. pylori, which I have probably had for years and years, but have never previously tested for, just fobbed off with IBS/GERD. Could there be any possible link there, too?
A. Adam: Lactose intolerance can certainly be the result of inflammation in the gut caused by infection, coeliac disease or even H. pylori, but by far the most common cause is genetic. Mammals are built to digest lactose from breast milk but, once we pass infancy, most of us lose the ability to tolerate lactose (as we don't rely on milk) and thus become lactose intolerant.
Q. PrettyCandles: What do you think about Guernsey milk and the theory that the form of casein it contains is less intolerable to humans than the form of casein in Friesian and Holstein milk? (For the benefit of other Mumsnetters who may not know what I am talking about, almost all dairy-farmed animals produce milk in which the beta-casein is predominantly A2, except for Friesian and Holstein cows, in which the nsumption is of A2 beta casein milk.)
My brother was a typically sickly, snotty, asthma-y, weedy kid in the 1960s and 70s. As an adult he realised that milk made him ill, and cut it out of his diet. He is now a farmer and has access to unhomogenised milk from a single herd of pure-bred Guernsey cows, and has discovered that he can safely drink their milk with no ill-effects, whereas 'conventional' milk still makes him ill.
I would also like to know whether, for someone with a dairy intolerance that is quality-of-life-affecting, rather than life-threatening, it is better to totally exclude dairy products or to consume them only in amounts that are small enough not to set off a reaction.
A. Adam: My experience has been that if your immune system has a problem with milk ie you are allergic, then it doesn't matter where the milk comes from, it is still a problem. Virtually all milk allergic kids will also react to goat/sheep milk. Very occasionally, I have patients who can tolerate specific milk-containing products yet react to others. This is most likely related to them having a problem with a specific milk protein that is not found in that product due to the manufacturing process. This may explain your brother being better with one milk rather than another.
As a rule, with delayed milk allergy (where there is no risk of anaphylaxis), if you can tolerate small amounts of milk without symptoms then there seems to be no harm in having them, but there is nothing to suggest that this would help you outgrow the problem.
Q. MoreBeta: I would like Lactofree cream and plain yoghurt, too. If you can lobby the manufacturers of Lactofree to do some, I am sure they would sell well. Having said that, I have never seen the Lactofree cheese or fruit yoghurts in my supermarket - only the milk.
A. Adam: I can only ask!
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Last updated: about 3 years ago