Allergies Explained - go back to home page Allergies

Grass pollen discharging granules on exposure to water - picture by Dr H Morrow Brown

Dust Mite - picture by Dr H Morrow Brown

Dr H Morrow Brown MD
General Medical Council Registered Specialist
for Allergy and Respiratory Medicine


Milk Allergy and Intolerance

• Home • About Dr H Morrow Brown • Contact Dr Morrow Brown • UK Allergy care • Disclaimer •

A Broad Introduction
Allergy Concepts
Food Issues
Rhinitis & Hay Fever
Children & Infants
Allergy to Animals
Finding Answers



Search the website

index sitemap advanced

How Milk Causes Problems from Cradle to Grave

The Dairy Revolution

MILK is for calves pictureThe widespread availability of milk and milk products today would be impossible but for the inventions of pasteurisation, refrigeration, and improved animal husbandry over the last 150 years. These developments have resulted in the production of such enormous quantities of milk that modern marketing techniques and aggressive advertising have become necessary to ensure its consumption. But cow’s milk was intended for calves, not for babies, who should always get human milk if possible.

Milk from all mammals is so similar that most babies can tolerate cow’s or goat’s milk in infant formulae, but a minority are unable to tolerate cow’s milk, and a few become very allergic to it. Goat’s milk is often suggested as an alternative, but goat’s milk is so similar in chemical structure that it is unacceptable. Occasional miraculous improvements from goat’s milk in babies with severe eczema hit the headlines, but it is uncommon.

Milk is seldom considered as a cause of disease, and its undoubted nutritional benefits accepted without question. But we were never intended to drink the milk of another animal from cradle to grave, and everyone cannot be expected to adapt seamlessly to this major change in diet. Most Asiatic people cannot tolerate milk because they become lactase deficient after infancy.

Milk and milk products can be the hidden cause of a great deal of ill-health at any age. There is even good evidence that increased consumption of milk may be responsible for the enormous increase in coronary disease which has also arisen since the industrial revolution Many years ago Dr Osborne, a Derby Pathologist published a monograph describing degenerative changes in the coronary arteries of bottle fed babies who had died suddenly which were absent in those who had been breast fed.

Milk Allergy is uncommon and produces acute problems, sometimes anaphylaxis, when tiny amounts cause rapid reactions which may be dangerous. Skin tests are often positive, blood tests show that there are IgE antibodies to milk in the blood, and the allergy may persist for life. Colic, screaming, vomiting, diarrhoea, colitis or eczema in totally breast fed babies suggests that sensitization of the foetus to foods in mother’s diet may have occurred. If manipulation of mother’s diet by excluding milk products, beef, and egg brings improvement then a serious allergy to milk may be present, and great care should be taken when introducing cow’s milk formulae because reacting to traces of cow’s milk protein in breast milk could indicate a dangerous allergy. That milk allergy can occur on the breast may not be believed, but demonstrating that the problems stop when the nursing mother stops milk, and recur she starts milk again should convince the most sceptical health professional.

Woman breast feeding a babyMy most striking case was a breast fed baby whose mother had noticed that every time she took wheat or milk the child had eczema and diarrhoea, and that one drop of milk or of a formula containing wheat caused alarming swelling of the mouth and tongue. This history was supported by positive skin tests and RAST for milk, beta lactoglobulin, and wheat.

This uneducated but intelligent mother had made the diagnosis herself, and all she wanted was confirmation, but she had not only been rubbished by her family doctor but also rejected by a paediatrician who told her that skin tests could not be done until the child was six years old, a common medical fallacy. The skin test reactions in this baby are shown below. Fortunately no-one had insisted on a milk feed, which might have been fatal.

I have known of milk allergic children deliberately given milk in hospital, and the ensuing reaction dismissed as psychosomatic. Dangerous reactions can be caused by well-meaning relatives, doctors, nurses, and health visitors who scoff at the idea that the idea that milk can be harmful.

Prick test reactions to wheat and milk in the breast fed baby

This baby dabbled his hands in spilt milk, thus making the diagnosis of milk allergy at a very early age from this skin reaction. Obviously babies can be skin tested !!

A sensitizing dose of milk may still be given by well-meaning but ignorant nursing staff in maternity units who give a bottle in the night rather than wake an exhausted mother to give the first feed of breast milk containing colostrum full of protective antibodies.

The result may be that the first taste of milk formula after stopping breast feeding may cause an alarming reaction, and mother may be unaware that the baby had been exposed to cow milk at birth.

I always remember a well-informed medically qualified mother who had to throw bottles of feed at the nurses before they would stop offering bottles to her baby.

Milk Intolerance is common but often not recognised
To illustrate the many ways in which milk intolerance can cause illness I will describe interesting cases seen over many years which could help the reader to recognise milk intolerance in its many disguises. Descriptions of the varied manifestations of milk intolerance by means of memorable case-histories can emphasise diagnostic clues in a way that tables of statistics can never achieve. The enormous range of problems which can be caused by milk is such that a diet completely free from any trace of milk products may be worth trying at any age if there is the slightest suspicion that milk might be involved because there no test yet available which can reliably diagnose or exclude the possibility of milk intolerance.

Diagram of the human gutReferring to the Global Diagram in the Introduction showing how allergies can affect any organ or system of the body, milk is taken into the stomach, and then passes into the intestine, or “gut”, which is a very large organ composed of living tissue devoted to the digestion and absorption of the food we must eat to survive. Food is broken down by digestive enzymes into small molecules of soluble substances which can be absorbed through the gut wall into the blood stream and metabolised to produce energy, but some undigested large molecules of milk will inevitably get into the blood and can reach a sensitised organ to cause a reaction such as eczema or asthma. Fortunately the majority of mankind are ordinary individuals who have no problems at all because they are perfectly adapted to tolerate the unnecessary milk in the modern diet.

My personal experience has been mainly involved with chronic intolerance syndromes at all ages, because acute allergic reactions to milk formulae are usually, but by no means always, identified by paediatricians shortly after birth, and are uncommon. Intolerance to milk is not IgE mediated, no antibodies are involved, it is frequently not diagnosed when it should be, and it is common. Skin tests are negative, specific IgE in the blood is absent, and anaphylaxis does not occur. Reactions are delayed or slow, may take days to develop, and normal amounts of milk are required to trigger a reaction. No validated immunological tests are yet available so it is essentially a clinical diagnosis based on the history.

The gut is obviously the most frequently involved organ system in childhood, frequently recovering spontaneously in time, thus confusing and often preventing the diagnosis of milk intolerance. The gut can be affected from one end to the other, from mouth ulcers to colitis or an itchy anus.

Rejection of a formula feed by vomiting or by diarrhoea, or projectile vomiting which may be mis-diagnosed as pyloric stenosis, may not be recognised as possibly due to milk. Damage to the gut lining caused by milk intolerance may lead indirectly to many other problems such as secondary lactase deficiency, malabsorption, failure to thrive, steatorrhoea with floating fatty smelly stools, occult bleeding, anaemia and colitis. Chronic constipation is also an unusual presentation of milk intolerance.

Onset of symptoms soon after changing from breast to bottle should give rise to a suspicion of milk intolerance. Onset at weaning suggests the development of allergy or intolerance to other foods, so mother’s memory of the relationship of symptoms to the introduction of new foods can be very important evidence. Vague abdominal colic for no reason, with bloating and a tendency to either diarrhoea or constipation can be due to milk intolerance.

The fact that the many and very variable symptoms of milk intolerance often resolve spontaneously has greatly reinforced scepticism in both medical and nursing professions regarding this diagnosis. Annual double blind challenges with milk have shown that milk intolerance in infants recovers spontaneously within a year in 50% of cases, in two years in 75%, and 90% by three years.. As a result milk as the possible cause of a problem is often dismissed, or even blamed on parental mismanagement. False reassurance is often given, and great distress caused to both children and parents while waiting for a remission, when simple avoidance could have brought blessed relief. This tendency to spontaneous recovery is probably why many doctors and health visitors were reluctant to accept the diagnosis of milk intolerance, and could not believe that milk can be bad for you, but this out-dated opinion is no longer quite so common.

MilkSimultaneous involvement of many organ systems is common and can cause a diagnosis of milk intolerance to be discarded because it seems impossible for one food to cause so many symptoms. On the other hand when several foods are also involved, avoiding milk alone may be ineffectual without avoiding the other foods at the same time, so this also can be cause of prematurely discarding this diagnosis. A trial diet containing only the few foods which very seldom cause allergy or intolerance may be necessary to establish beyond doubt whether other foods have any relevance to the symptoms. Most adult patients can be persuaded to try this approach, as all they have to lose is a little weight, but infants have little choice in the matter.

The extent of processing influences the potential of milk or formula to cause reactions. For example one little boy could tolerate milk sterilized at 100 degrees, but pasteurized at 60 degrees caused asthma. Others may tolerate pasteurized, evaporated or condensed milk, but this is rare.. The development of extensively hydrolysed formulae where the milk proteins have been destroyed as far as possible, or Complete Elemental diet 028, can be very helpful for test diets. These special formulae can be prescribed on the NHS.

The only way to make a definite diagnosis is by demonstrating improvement by avoidance, followed by re-introduction which can be seen to reproduce the symptoms on at least two, or ideally three occasions. In milk intolerance normal amounts of milk are necessary to reproduce symptoms, and the reaction, whatever form it may take, is usually delayed. It is difficult to realise that infants are consuming the equivalent of ten litres of milk a day for a 70 Kilo adult! Some milk intolerant adults are positively addicted to milk and take large quantities, in marked contrast to those with IgE mediated allergy who react very quickly.

When milk intolerance gets better spontaneously in late infancy, it is often replaced by inhalant allergies. The persistence of covert symptoms of milk intolerance such as vague abdominal pains and behaviour problems may be the unrecognized cause of long-lasting misery for both child and parents. A craving for milk and consumption of large quantities can be a useful pointer because it is not uncommon for the patient to have a craving for the very food which is the cause of the misery.

To diagnose milk intolerance demands a high index of suspicion, knowledge of the diagnostic pointers, awareness of the right questions to ask the patient or parent, and, above all, time to listen. It is important to realize that laboratory tests are no help, and that a negative RAST or skin test does not exclude intolerance. Negative tests can lead to the parents being incorrectly assured that milk cannot be the answer. The infant feeding history and the family history are most important at all ages, with reference not only to the patient but also near relatives, who may display different manifestations of milk intolerance in other organs of the body. Even transient infant feeding problems recalled by an elderly patient can suggest milk as a possible cause of “ late onset” asthma. Mention of malabsorption, chronic diarrhoea, or constipation, also suggest a milk problem.

The simple experiment of removing milk from the diet to find out if the patient gets better would not seem to be a revolutionary concept, yet the resistance of some medical practitioners, and even some paediatricians, to this simple approach is remarkable. When the suggestion that milk may be causing trouble is made by parents or by patients themselves the idea is even more likely to be rejected, thus driving them into the hands of the quacks and charlatans who have no inhibitions about giving all manner of “advice”.

Perhaps it is surprising that adverse reactions towards the first foreign proteins we encounter are so uncommon, and fortunate that most people can tolerate cow’s milk, which we now consume daily from cradle to grave in much larger amounts than our grandparents did.

Management of Milk Intolerance

Management cannot begin unless intolerance is suspected or recognized. Diagnosis is easier in infancy as the diet is so simple, but becomes progressively more difficult with increasing age involving a wider range of foods. Complete exclusion of all milk products, including beef, is the first step whatever the age. Soya formulae are the first choice, but remember that with increased usage of milk-free formulae allergy or intolerance to soya has become more common. Other mammalian milks such as goat or sheep are often recommended but may not be tolerated. Beef should be excluded at first in all patients because it is the source of cow’s milk. It is difficult to understand why British dietitians will not accept that beef should also be excluded, because in my experience one case in four also reacts to beef, as was recently confirmed by a group in the USA..

A joint of roast beefBeef is also the source of gelatin, which has been definitely proved to cause occasional anaphylaxis when contained in vaccines, and is also when used in sweets such as jelly-babies, and for making jellies. Guidance on avoidance of milk products should be available from the dieticians at any health centre, but these views on milk and especially beef may be unacceptable. Supermarkets now offer a range of “free from” products, and useful lists which are very helpful.

Symptoms should disappear completely in a week or two on strict avoidance, but may take longer, so it is important not to conclude prematurely that milk has been exonerated. The quicker the improvement the more likely is milk the correct answer, the slower the response the less likely.

Reintroduction of normal amounts must reproduce the symptoms, which are often delayed, and they should vanish again on withdrawal. This sequence should be repeated twice more to be really certain that a valuable food must be avoided, and that a milk free diet is really necessary. This test should be performed within a month, accidental challenges often providing the most convincing evidence.

If a milk-free diet alone does not produce improvement it is unwise to assume that food intolerance has been totally excluded. Multiple sensitivities are common, so it may be necessary with older children to introduce a diet for a week or two consisting of only the very few foods which hardly ever cause intolerance syndromes, followed when successful by reintroduction of single foods one by one to find the culprits.

Double blind placebo controlled challenges, although necessary for research, are impractical in clinical practice. In the past I found it more difficult to control the diet in hospital than when collaborating closely with the patient or mother as an out-patient. Of course the full cooperation of the family as partners in the enterprise is essential to ensure rigid adherence to a diet.

In my experience handing out diet sheets provides totally insufficient motivation, and if a dietitian is involved she should be one of those very rare individuals who are really interested in food allergy and intolerance. The best results are obtained by arranging for weekly telephone reports which maintain contact with the patient and give encouragement and support for their efforts.

The above comments apply to suspected milk intolerance at any age, sometimes quite elderly. The many effects of milk in causing other manifestations of allergy are to be found elsewhere in this website, and the clues to the diagnosis are usually somewhere in the history, which takes time to sort out.


"It is a paradox that while Britain has the highest incidence of allergic disease in the world, it also has the most inadequate allergy service"

• Home • About Dr H Morrow Brown • Contact Dr Morrow Brown • UK Allergy care • Disclaimer •

Copyright © 2011 Dr. H Morrow Brown. All Rights Reserved