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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


Hidden Food Allergy and Intolerance

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Case Histories illustrating how hidden food allergy or intolerance can cause severe asthma

Food allergy or intolerance may lurk undetected for many years totally concealed by obvious positive skin and blood tests to dust mites and animals. Very few consultants are aware of this possibility in so-called “brittle” asthmatics who may not have had any allergy tests at all and rely on drugs only.

Three small kittensA good example is Ann, who came from a very allergic family, and was first seen in 24 years ago in 1981.At the time she was aged 27 with a history of chronic asthma since childhood, much better when away from home away from the dog, and also better on leaving home to get married until they introduced dogs again. She was instructed to get rid of the dogs, and her peak flow rate doubled, but she was also very sensitive to house dust, so she was completely desensitised by a series of injections. It then became obvious that contact with visitors who possessed cats, dogs, or horses was enough to cause an attack of asthma. Visiting friends who had a cat resulted in admission to hospital with severe asthma for a few days. Accepting a lift in a car which had a horse blanket on the back seat which had had a cat sleeping on it, brought on an acute attack.

With careful avoidance of animals and having no effects from house dust her asthma was easily controlled, and she was not seen again for six years. She had begun to react to dust again in 1990, especially when she was studying in the University library near an air duct discharging into the room. On reassessment it was clear that apart from still reacting to traces of animals on other people’s clothes the major problem was dust mite but by this time desensitising injections had been banned for asthma in the UK, so she could not have specific treatments to desensitise her once more .

Bottles of AcarosanThis time Acarosan was available to kill off the mites, plus removal of carpets, and new bedding. These measures brought remarkable improvement in the home environment, but she was so sensitive to dust mites that she would begin to cough and wheeze in any carpeted area, even one of these lifts which has carpet on all surfaces. At University she had to take an examination in a room which was totally carpeted, but developed asthma and coughing to the extent that she had to take the exam again in a room with no carpets.

For the next few years she was able to control the asthma with difficulty using Becotide and bronchodilators, and the home environment was made free from carpets and soft furnishings which could harbour the mites. In 1998 the asthma became completely uncontrollable as a result of exposure to horses when taking her children horse-riding. On reassessment of the home environment by using extracts of the house-dust for skin testing it was clear that the mites had returned in force, so this was dealt with again using Acarosan, and she was reasonably stable for another seven years.

Antacid tabletsThen she began working in a social services office which was very neglected and dirty with ancient carpets and a leaky roof. The acid rain dissolved some of the plaster so that when the roof dried out tiny stalactites formed which she brought to show me!

She developed asthma whenever she worked in this office which got worse from Monday to Friday and was better at the weekends. She had also developed reflux of gastric acid which caused coughing so severe that she could hardly speak on the telephone.

Treatment with drugs to suppress the acid was very helpful, but she then gave a new history of severe indigestion and high consumption of antacid tablets for about twenty years at least which neither she nor I had connected with her allergies.

The Belated Discovery of the Food Factor

At this consultation I observed that she had very heavy shadows under the eyes, an appearance often suggestive of a food allergy, and on questioning she admitted that she had noticed that many milk products and other foods made the asthma worse. She was placed on a diet containing only the few foods which rarely cause allergic problems, with the result that within a few days the asthma, cough, and also chronic indigestion with reflux, all practically disappeared, except for asthma when she worked at the dusty dirty office.

Foods were then reintroduced one by one, and it was repeatedly shown that any trace of milk or beef, potato, chocolate, any citrus fruits, or wheat would cause cough, sputum, and wheezing. A few chips produced cough and wheeze in half an hour, a little milk in tea or a rare steak caused cough and wheeze in a few minutes for two hours, and wheat caused not only wheezing and cough for a full day, but also bloating with an increase of six inches in her waist measurement. Chocolate and red wine produced migraine. It is characteristic of food allergy and intolerance that these were the foods she was most fond of, and she found it very difficult to abstain from eating them.

Becotide inhalerAs a result she lost 21 pounds in weight, which was very welcome as she was obese anyway. She now has no bloating after meals and no indigestion for the first time in over twenty years, and has practically no asthma. Her drug requirements are much less, taking only Becotide 100 mgm morning and evening, with no bronchodilators and no antacids. When she had a wheezy attack recently there was panic because she did not know where her Ventolin inhaler was! Her lung function tests were normal for her age and height for the first time in 24 years, and she for the first time was able to go cycling with the family, going up hills without difficulty. The heavy shadows under the eyes faded appreciably, and the only time she had asthma was when she went to work in the dirty office. Fortunately this office has now been demolished, she works in a clean new office, and she has no asthma at work or home for the first time in years.

Gravy in a dishSince then she has completely abstained from these foods except when taken by accident or for a deliberate test. Yoghourt will bring on a runny nose in minutes, followed by excessive secretion of mucus, cough, and wheeze for 12 to 24 hours. On holiday she had what was said to be a turkey sausage, but she began to cough uncontrollably. The chef had to confess that there was some beef as well as turkey in the sausage. Potato causes acute indigestion, wheezing, and nose running. A very small amount of gravy in a restaurant caused acute indigestion for 24 hours, cough, sneezing, and wheezing, and this was found to have been made with beef stock.

This remarkable case history, over on less than a quarter of a century, demonstrates just how complicated allergic problems can be to manage unless the causes can be identified. The obvious allergies were the extreme sensitivity to animals and mites, which completely obscured the background food allergies. This case demonstrates dramatically how suppression with drugs is only one part of the treatment, and why all possibilities must be considered. The fact that the chronic indigestion has ceased completely for the first time in 20 years, and only recurs when the wrong food is eaten, suggests that the stomach was hypersensitive or allergic to these foods and that the secretion of excess acid was due to an allergic reaction. But nobody had connected her indigestion with her asthma, including myself!

A Very Complex Problem without Hard Evidence

OrangesDenise was 46 when first seen, with a family history of asthma back to her maternal grandmother and onwards to her two daughters, one having intolerance of gluten, not wheat, and the other hay fever. She had been diagnosed as Coeliac disease as a child, but this diagnosis was revised later. She had had undiagnosed asthma since childhood and was aware that chocolate, tomatoes, and oranges caused itching and swelling of the face. The asthma had recently become a problem and was difficult to control in spite of treatment with Becotide for the first time.

A field of newly cut grassShe stated that egg caused diarrhoea, that she had a craving for cheese, and got severe hay fever and wheezing if she was near grass cutting, laurel hedges, cut grass, and raking the lawn. She also was worse if it was raining. She had had an aversion to milk as a child, and if she drank any she got a runny nose and itchy eyes. Her symptoms improved if she drove into the middle of Birmingham away from the country, suggesting sensitivity to mould spores.

On return from holiday she found that there had been a leak from the upstairs bathroom, with the result that the paper on the ceiling below was bulging with water, and there were small mushrooms growing on the paper. The effect of exposure to this house brought her peak flow down by 50% in 15 minutes, so she had to live elsewhere until the house was dried out, always having asthma when she came to see how drying out was progressing.

She was skin tested with a great many allergens but responded to none. Total IgE was low, and no IgE antibodies against anything tested were found in her blood, even when sent to Dr Roland Van Rhee in Holland, an internationally renowned immunologist. She was having rapid reactions characteristic of an IgE mediated allergic reaction, yet neither skin nor blood tests could confirm that this was occurring. Samples of mouldy carpet were found to be growing Stachybotrys, a rather toxic mould which has been known to cause asthma.

Breaded fishShe was controlled with Becotide for some time, but she has also learned how to track down her various food allergies with great success by following my dietary instructions. I considered that it would be only by careful dietary manipulation that she would be able to identify the causes of her problem. She has discovered that she is reproducibly allergic or intolerant of all dairy foods, gluten, fish, and shellfish, and that intentional or inadvertent consumption of any of these would produce wheezing, itching, and sneezing within an hour. From her reports it is evident that the trigger foods also affect brain function as well as the gut and respiratory system.

She can take gluten free bread, so she can tolerate wheat, but anything containing gluten causes bloating and constipation for several days followed by watery vile stools for a week, but tests for coeliac are negative. She can tolerate potato yet reacts to tomato. She found that fish was one of the worst to cause asthma, and even the smell of fish will cause a running nose at once. In the past she had severe reactions to eating fish, once even becoming unconscious for a short time until she vomited up the fish and recovered.

Dairy productsHer sensitivity to dairy foods is extreme, and she has a craving for cheese. Even a trace of whey in a meal in a restaurant has several times caused severe abdominal cramps and diarrhoea within an hour, and is also followed by a very rapid pulse and a zombie-like feeling when she cannot think clearly for some days. Any dietary mistake or indiscretion also causes tiredness and feeling generally miserable for a few days, more like an intolerance reaction.

As a result of careful avoidance of these foods she has been in good health for the last thirteen years, and does not require any medication except an occasional antihistamine. Obviously this is yet another case where the hidden food intolerance or allergy was the major problem, and her more obvious reactions to moulds in damp houses or in the garden are no longer enough to set off her reactions.

It would appear that as long as she avoids the foods to which she reacts the exposure to moulds and other allergens is insufficient to push her over her tolerance level. The total failure of two laboratories, one with international reputation for research, to explain any of her problems by immunological results is of great interest.

It must be said that once she was shown to way to sort out her problems in an orderly manner she followed that path meticulously and achieved good health without drugs. Whatever the actual mechanism involved, it is evident that the brain, the digestive tract, and the lungs are all involved in the reactions. Just as in the case of Ann, as long as the foods are avoided the inhalant allergens have no effect.

This case is another where a modern evidence based approach to the problem would have been totally unproductive, as the total absence of any objective evidence from scientific tests would lead to a diagnosis of chronic late onset type asthma with a prominent emotional component.

As usual, the clinical key to the problem lay in a careful history which picked up the possible causative foods, followed by teaching the patient how to investigate the cause/effect relationships of her symptoms with foods. Of course this entailed involving the patient as a partner in the investigation, as otherwise nothing would have been achieved.

Dust Mite Allergy Concealing Milk Allergy as the Major Cause of Asthma

Ventolin inhalerMary had had severe infant feeding problems followed by chronic asthma until she was seen for the first time aged 28. Her story was that she had been given oral steroids by her GP for the first time for her asthma and had developed such an emotional crisis that she was admitted to a psychiatric hospital.

Steroids were blamed for her emotional state, but in my experience this is an exceptionally rare side-effect. In the Psychiatric Unit her Ventolin inhaler, which she regarded as her ‘lifeline’, was taken away from her, presumably in case she over-used it, and no attention was paid to the fact that she had had her first baby two weeks before, her husband had just been made redundant, and he could not visit her because he had broken his leg and could not drive!

Unsurprisingly, she discharged herself from the Psychiatric Unit, and was very soon admitted to hospital under my care. Her asthma was treated with high dose of oral steroids without any emotional consequences, but the essential difference was that at the same time milk was totally avoided because the significance of her infant feeding history suggesting milk allergy was recognized. Steroids were gradually stopped, and she became free from asthma without any medication whatsoever for the first time since infancy.

As shown in the Peak Flow chart below, provocation tests with small amounts of milk before leaving hospital produced repeatable reactions which were unexpectedly severe and clearly indicated that she was allergic, not intolerant, of milk as even a tiny amount caused severe asthma very quickly.

She also had very large skin test reactions and a very positive RAST test for mites, but the skin prick test and RAST blood test for milk were negative. In this case the important allergen was milk, which was hiding in the background while the immunology and skin tests pointed very clearly to dust mite as the major cause of her asthma. The correct diagnosis was suggested by the history, but the scientific tests indicated a superficial dust allergy of no importance as the cause of the asthma. She has been well ever since, except for very mild dust sensitivity, but has to avoid milk products indefinitely.

Chronic indigestion with acid reflux is well known as a common cause of severe cough, but if the cause of the excess acid is another allergic reaction in the stomach a diet trial would be an excellent way to exclude this possibility, which was first suggested in 1926 but long fogotten!! There is nothing to lose except some weight !!

These “anecdotal” reports suggest that it might be worth while placing all the severe, and especially the steroid dependent, asthmatics who are often labelled “Brittle Asthma” on a “Few Foods” diet just to make sure that a food allergy or intolerance is not being overlooked. There is nothing to lose except a few pounds, because if there is no improvement after three weeks a hidden food allergy has been excluded.


"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"

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