Milk Intolerance Spectrum

Dr Harry Morrow Brown (Emeritus Consultant Physician & Allergist from Derby) has spent nearly 50 years studying and working with allergy of all kinds. One of his special interests has always been milk allergy and the relationship of asthma to allergy. The following is the bones of his paper which was published in the Journal of Nutritional and Environmental Medicine in 2002.

Fifty years ago, when tuberculosis was rife, Chest Clinics looked after the whole family from cradle to grave. My unique experience working in such a clinic gave me the opportunity to observe how allergy or intolerance to milk and other foods could affect two or even three generations. This would be impossible today because specialisation has created barriers to the holistic approach which is essential for the recognition of the diverse illnesses caused by reactions to food or environment.

When allergens are ingested, inhaled, or contacted, they are distributed in blood and body fluids to every cell in the body. The symptoms that result will depend on which organ or organs have been sensitised. To complicate the issue, there may also be several allergens involved. In eczema for example milk proteins absorbed from the gut reach the sensitized skin where the reaction takes place. If milk is the only allergen to which the skin is sensitized then milk avoidance should be completely effective, but the skin could also be sensitive to environmental allergens such as dust mites or pets explaining why avoidance of milk alone is often ineffectual.

In the 20th century advances in animal husbandry, nutrition, and food technology revolutionized the dairying industry. Improved hygiene, pasteurisation, and tuberculosis free herds made cow's milk safe, and enormous quantities were produced which had to be sold. Milk Marketing organizations have promoted the value of milk to such an extent that the medical profession, as well as the general public, have become convinced that milk is always good for you. The idea that milk can be also very bad for you has become almost heresy, and the fact that cow's milk was intended for baby cows, not for baby humans, seems to have been forgotten.

Breast milk from mother or wet-nurse was the normal infant feed until about a hundred years ago when technical developments enabled the manufacture of cow's milk based infant formulae. As a result, until the recent revival in breastfeeding, few babies ever tasted the food that nature intended for them.

The simple experiment of removing cow's milk products from the diet to find out if the patient gets better would not appear to be a revolutionary concept, yet the resistance of practitioners, and even some paediatricians, to a trial of this simple approach is remarkable. When this suggestion comes from patients or parents it is even more liable to be rejected.

Milk Allergy

It is essential to define the differences between IgE mediated allergy (involving the immune system) and intolerance - although they can co-exist. IgE mediated allergy to milk is uncommon. Reactions are sudden and dramatic and can be triggered by very small amounts of milk.

Since the revival of breast feeding the incidence of allergy among breast fed infants to foods in the mother’s diet has increased, so that colic, diarrhoea, crying after feeds or eczema in totally breast fed babies should suggest allergy to milk or other foods in her diet.

If exclusion of milk products, beef, and egg from the mother’s diet brings improvement, allergy may be present, so great caution should be exercised on introducing milk formulae. Reacting to minute traces of cow’s milk protein in breast milk indicates a high degree of sensitivity. Dangerous reactions can be caused by well-meaning relatives, doctors, or nurses who scoff at the idea that milk can be harmful. A sensitizing dose of milk may be given by well-meaning but ignorant nursing staff in maternity hospitals who give a bottle in the night rather than wake mother to give the first feed. As a result the first taste of milk formula after breast feeding ceases may cause an alarming reaction.

My 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 intelligent mother made the diagnosis herself yet she had been rubbished both by her family doctor and a paediatrician.

In Britain recognition of milk allergy has been very slow amongst health professionals. From 1960 to 1988 twenty papers were published by Professor Robin Coombs, Bill Parish, and collaborators supporting the theory that some cases of cot death could be caused by an IgE mediated anaphylactic reaction caused by inhalation of a cow’s milk formula feed. Yet this work attracted little attention and was never followed up. (1)

Milk Intolerance

Intolerance to milk does not involve the immune system, is frequently undiagnosed, and is common. Skin tests are negative and anaphylaxis does not occur. Reactions may take days to develop, and normal amounts of milk are required to trigger a reaction. The only way to make a firm diagnosis is by demonstrating improvement on avoidance of milk, followed by ‘challenge tests in which symptoms can be shown to recur on the ingestion of milk. Annual double blind challenges have shown that milk intolerance in infants recovers spontaneously in a year in half of the cases, three-quarters in two years, and 90% in three years (2). This tendency of milk intolerance to spontaneous recovery has greatly reinforced skepticism among the medical professions regarding the diagnosis. As a result milk as the possible cause of a problem is usually dismissed, or even blamed on parental mismanagement.

To diagnose milk intolerance demands a high index of suspicion and awareness of the right questions to ask and, above all, time to listen. It is important to realize that skin and laboratory tests are no help. The infant feeding history and the family history are most important at all ages. Even transient infant feeding problems recalled by an elderly patient can suggest that milk is a possible cause of ‘late onset asthma. Mention of malabsorption, chronic diarrhoea, constipation, colitis or projectile vomiting may also suggest a milk problem.

In infants the gastro-intestinal tract is the main target, but the symptoms can be extremely variable and change with time. Onset of symptoms soon after changing from breast to bottle should give rise to a suspicion of milk allergy or intolerance. Onset at weaning suggests intolerance to other foods. Vague abdominal colic for no reason, with bloating and a tendency to diarrhoea or constipation can be due to milk intolerance. Milk intolerance causing severe gut inflammation can damage the lining of the gut sufficiently to cause secondary lactose or gluten intolerance, which may clear up spontaneously and quite rapidly once milk is avoided.

Simultaneous involvement of all of the body's 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. If several foods are involved avoiding milk alone may be ineffectual and a trial diet containing only a few totally non allergenic foods may be necessary to establish beyond doubt that it is food that is causing the symptoms. It should also be remembered that the extent of heat processing of the food influences its allergenicity. For example one little boy could tolerate sterilized milk, but pasteurized milk caused asthma. Milk intolerance often disappears in late infancy, only to be replaced by inhalant allergies. A craving for milk should always arouse suspicion as it is common for the patient to have a craving for the very food which is the cause of the misery.

Management of Intolerance

Management cannot commence unless intolerance is suspected or recognized. Complete exclusion of all milk products is the first step whatever the age. Soya formulae are the first choice substitute for infants, although intolerance to soya is becoming more common. Other mammalian milks (goat or sheep) are often recommended but rarely 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 I have found it so difficult to convince British dietitians that beef should also be excluded, but about one case in four reacts to beef, as recently confirmed (3).

My most striking case was a baby whose incessant watery diarrhoea was so malodorous as to make the home almost uninhabitable. A hospital dietitian had put him on a milk-free, but not beef free regime and there was no improvement. In spite of the constant screaming and the smell, his parents took him on a bus tour round Europe for two weeks! Fortunately he was perfectly well on the bus but promptly relapsed on return home. On investigation it was found that by chance they had taken with them a large supply of infant foods from a different maker which did not have a beef broth base. When all trace of beef as well as milk was excluded his symptoms cleared in a few days.

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 is in the clear. For the diagnosis to be reliable reintroduction of normal amounts must reproduce the symptoms, and they should vanish again on withdrawal. Multiple sensitivities are common, so it may be necessary to introduce a diet consisting of only the very few foods which hardly ever cause intolerance for a few weeks, followed by a serial re-introduction of each suspect food.

Although at the present time the medical anecdote is unfashionable, a striking story is much easier to remember than a statistic, and can lead to the recognition of similar cases. I therefore make no apology in relating a few relevant cases from my experience in practice.


A lady who had had severe infant feeding problems followed by chronic asthma was first seen aged 28. She had been given oral steroids for the first time and had such an emotional crisis that she was admitted to a psychiatric hospital. where the steroids were blamed for her emotional state, and her bronchodilator spray was taken away from her! No notice was taken of the fact that she had had her first child two weeks before, her husband had been made redundant, and he had also broken his leg so that he could not drive.

Unsurprisingly, she walked out, and was then admitted to my Chest Hospital. Her asthma was treated with high dose steroids without any emotional consequences, but milk was totally avoided because of her infant feeding history. Steroids were gradually stopped, and she became free from asthma without any medication for the first time since infancy. She had very major skin test reactions to dust mite but negative skin and blood tests to milk although it was in fact the milk which was the major allergen. Which proves yet again that one cannot rely on skin or blood tests when milk allergy is suspected, but must assess the patient in the light of their medical and familial history.

Runny Nose and Glue Ear

David was aged ten, and had had perennial rhinitis (runny nose), frequent otitis media (glue ear), and frequent tonsillitis for five years, and been hyperactive since infancy. His nose was almost completely blocked, he was partially deaf due to the otitis media, and he was very difficult to handle. The clues were that his mother was atopic (prone to allergy), his sister had been suspected of being intolerant of milk as an infant, and his grandfather had died of ulcerative colitis when on a high milk diet. Skin and blood tests were all negative. After milk avoidance for eight weeks his hearing had recovered completely, and his nose was completely unblocked. His behaviour had become normal for the first time but reverted every time he stole milk from the refrigerator.

Malabsorption and Milk

A girl aged one was referred with chronic asthma. Her mother and grandmother had a history of bronchial problems. She had been bottle fed, and had been hospitalized with gastroenteritis, malabsorption, and failure to thrive. She was very small and miserable. It was established that vomiting and diarrhoea were associated with milk and beef based baby foods. All symptoms subsided on avoidance of milk and beef products. She was then lost sight of until age five when she was a miserable but hyperactive stunted child with a pigeon chest, asthma and loose motions. On total milk avoidance the hyperactivity, tantrums, loose motions, and asthma disappeared again in a few days but would reappear within 4 hours of drinking milk. Off milk products she began to grow rapidly, but by age eight she had become sensitive to grass pollen, dog, and horse. Age ten she was an active delightful child with a normal peak flow rate. Aged twelve she won a five mile cross-country race against much bigger children, but she never achieved normal height.

Eczema can have multiple causes

John aged two had very severe eczema which improved considerably on milk avoidance, but cleared completely when the family went on holiday. On the way home in the car the family dog was collected from the boarding kennels, and by the time they reached home John was scratching himself to pieces. The dog was found a good home and John had no further eczema.

A girl aged five had severe eczema which cleared completely on avoiding milk, but relapsed acutely when she went to stay for a week with her grandmother who had a dog. If she had always lived with her grandmother and the dog, avoidance of milk would not have cleared the eczema so would have been discounted as a cause of her eczema. In fact her eczema was multi factorial and required the avoidance of both milk and dogs to be resolved.

Irritable Bowel Syndrome

Although the current opinion regarding IBS is that it is usually psychosomatic (imaginary), Dr John Hunter in Cambridge has shown clearly that normal amounts of foods, particularly milk and wheat, will provoke symptoms of IBS. [4] Personal experience over many years has confirmed his views.


Although chronic constipation is an uncommon symptom of milk intolerance, it is not unknown.

My best example is a girl aged nine who had a history of severe infant feeding difficulties, followed by chronic asthma, and constipation so severe that she usually passed a motion once in about two weeks. The product was described as being the size of a milk bottle (!), which had to be broken up to be flushed away. A paediatrician had insisted that all her problems were due to the marital discord which had led to her mother’s divorce, but avoidance of milk products not only resolved her asthma in a week but she also passed normal stools daily for the first time since infancy. Re-introduction of milk repeatably reproduced both asthma and constipation.


Diarrhoea is a common presentation of intolerance, especially in infancy. When due to milk intolerance it can cause damage to the wall of the gut which, in turn, can cause lactase deficiency (inability to digest the lactose sugar in milk), malabsorption of nutrients, fat or blood in the stools, failure to thrive, and anaemia.

A five-year-old boy was referred with rhinitis and cough, but also had a history of projectile vomiting which ceased as the rhinitis and cough began. He had constant rumbling stomach, wind and bloating, and only two very smelly motions per week. He was very difficult to handle, but all skin tests were negative. Avoidance of milk resulted in disappearance of all symptoms in a week and normal behaviour. His mother commented that when she gave him test feeds of milk his behaviour became as foul as the smell of the huge stools which ensued!

Musculo-Skeletal System - Arthritis

I have seen at least 30 cases over the years where I have suspected food although this has been dismissed by medical advisers. The clue has often been that when the patient is unable to eat for some reason the joint pain improved.

A lady aged 34 had a history of fluctuating pain in all her joints, her abdomen, chest and shoulders without any evidence of joint disease. She had had extensive investigations and variable diagnoses by three physicians, an orthopaedic surgeon, and a psychiatrist who diagnosed manic depressive psychosis in a hysterical personality. Skin and blood tests were all negative. She then began working in London staying, during the week, with a vegetarian who did not take milk. Her pains got progressively better in the week only to relapse abruptly at home during the weekend. When she gave up this job and returned home to a 'normal' diet she became much worse but a milk free diet gave complete freedom from pain within a few days, repeatedly provoked by a trace of milk. The emotional disturbance, which had doubtless been secondary to the milk intolerance, also disappeared.

A teacher aged 53, had had worsening polyarthritis for four years which cleared completely on a 'few foods' diet. A small amount of milk would repeatably cause a relapse in six hours lasting for three days. She was very happy avoiding milk products, but observed that her joints ached the morning after intercourse. Using a condom prevented this effect. So her husband also avoided milk. He discovered that his chronic otitis externa (swimmers' ear) cleared up for the first time in 30 years while intercourse without a condom no longer caused her joints to ache. To confirm this bizarre example of milk allergy or intolerance in a manner acceptable to evidence based medicine intercourse would have to be repeated with another partner when taking milk and when abstaining from milk, and all participants would have to be blindfolded. They did not feel that they were prepared to cooperate in this experiment!

Central Nervous System

The emotional aspects of milk intolerance are variable and bizarre. Milk intolerant children often have a short attention span, cannot sit still, and have tantrums, poor co-ordination, a tendency to self-injury and destructiveness, which occur repeatably after consumption of milk.

A girl aged ten had been formula fed, and had eczema from birth to age four. Aged about one she had frequent sinus infections, and serous otitis media (glue ear) for which grommets were inserted twice, orthodontic problems and a high palate. At 6 her school report commented that her behaviour and writing varied from day to day. She had very heavy shadows under the eyes which suggests intolerance. Her mother had noted that she became hyperactive and aggressive after having anything containing dyes such as tartrazine. Blood tests were unhelpful, but milk avoidance brought a dramatic improvement. In the ensuing years she progressed very well both physically and mentally, except when she had milk or milk chocolate, for which she has a definite addiction. The orthodontic problems, which are often due to unrecognized nasal allergy, resolved completely.

Why not treat Intolerance in General Practice?

The general practitioner, who ought to know the family and their environment better than anyone else, is at the present time the only medical professional who is in a situation to recognize and treat intolerance to milk or other foods. Unfortunately ignorance of the enormous potential of food to cause disease is very common not only amongst GPs but even amongst children's specialists, and expert advice is very difficult to find. Paradoxically, the remarkable increase in allergic disease in recent decades has been accompanied by a progressive decrease in the number of clinical allergists in the NHS, until now there is only one for every three million people in Britain.

I have no doubt that intolerance could be treated effectively by the family doctor by simple dietary manipulation, given the time, the knowledge, and the motivation. It can be an inspiring and rewarding experience to actually cure a patient by identifying the cause and avoiding it, rather than simply masking the symptoms with suppressive drugs. Intolerance to foods other than milk is also common especially to wheat (often the cause of IBS) - as is undiagnosed coeliac disease for which really accurate blood tests are now available to the General Practitioner.

Perhaps food allergy and intolerance could become the special interest of one of the partners in the practice, or the practice nurse, and could include all the ailments caused by milk and other foods in adults and children. However, for success it is vital that the patient is seen by the same doctor or nurse on every occasion. It is essential to realize that each case has a unique pattern of response which can only be sorted out by trial and error and observation of the relationship of symptoms to foods. It is also essential to increase the awareness of patient or parents to the possibilities. Properly informed, the intelligent patient will often find the answer before their medical adviser.

[1] Coombs RRA, Parish WE, Walls A F, Sudden Infant Death Syndrome Cambridge Publications Ltd, pub 2000 Cambridge
[2] Hill DJ, Hosking CS, Emerging disease profiles in infants and young children with food allergy Pediatr Allergy Immunol 1997, 8 (supp 10 ) : 21-26
[3] Werfel SJ, Cooke SK, Sampson HA. Clinical reactivity to beef in children allergic to cow’s milk J All. & Clin Immunol. 1997;99:293-300
[4] Hunter JO, Jones VA, Food and the Gut Bailliere Tindall London 1985

The full text of Dr Morrow Brown’s article can be found in the Journal of Nutritional & Environmental Medicine (2002) 12(3), 153-174

You can contact Dr Morrow Brown at Highfield House, Highfield Gardens, Derby DE22 1HT
Tel. 01332 331500 Fax. 01332 361748

His book, All about Asthma and Allergy, is available direct from Dr Morrow Brown - price £10 inc P&P

First published in 2003


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