Q Having read 'Choking on Medicine' (vol 4 no 6), how real are the dangers of coming off asthma drugs, and what precautions should be taken?- P D W, Dyfed.

A Here are the suggestions of John Mansfield and David Freed, who wrote the original story we extracted.

'You could try Fox's approach to a new case of asthma in a child - reassure the parents and ignore the condition. The patient may suffer but he will not die unless you treat him.

'You could try to identify the offending substances and try to avoid them. In practical terms this could begin before birth, with pregnant mothers avoiding the commonest food allergens, continuing avoidance during lactation and at the same time reducing the dustmite levels in the house by well-established house-cleansing methods. Although laborious, this regime does prevent much allergy in genetically susceptible babies.

'You could try to find out what is causing the individual patient's asthma by taking a highly detailed history, which is oriented toward cause and effect. Patients who are sensitive to inhaled allergens often have observed that dusty environments, damp, mouldy places, animal hair, feathers and so forth provoke their asthma. 'Sometimes the asthma occurs seasonally and is hence related to summer pollens or moulds which are prevalent at certain times of the year. These patients are usually positive in a prick test to housedust, dustmites, moulds, animals, feathers and summer pollens.

'Other asthmatic patients, who do not have these features in their history and may be negative to inhalant prick tests, usually are labelled 'intrinsic asthma'. In our experience, such patients are usually food-intolerant; sorting out their specific intolerances usually leads to a successful resolution of their problem. (See also Rowe AH, Food Allergy, Springfield: Charles C Thomas, 1972).

'A strategy used in many clinics such as ours is to put a patient on a 14-food oligo-antigenic diet (lamb, cod, trout, mackerel, salmon, pears, carrots, Chinese bean sprouts, sweet potatoes, parsnips, turnips, Swedes, marrow, courgettes and bottled water). In patients whose asthma is related to food, symptoms normally clear within seven days on this diet. Reintroducing foods back into their diet sequentially and observing reactions, which vary strongly from patient to patient, usually isolate the culprit or culprits, although cow's milk and various grains such as wheat and maize figure predominantly in many cases.

'If the patient appears to be suffering with inhalant allergies, and avoidance regimes such as frequent vacuuming and chemicals to inhibit housedust mites have been tried and failed, the only satisfactory method of dealing with this problem, in our view, is intradermal neutralization therapy, or desensitization. 'This technique consists of testing the patient's skin with various concentrations of suspected allergens, either inhaled or food. Reactions may occur on the stronger concentrations of the allergens tests and the patient is then tested with successively weaker extracts until a neutralizing concentration is identified. This concentration is the strongest concentration which doesn't provoke a positive wheal reaction.

'The practitioner then makes up a cocktail of neutralizing levels of the offending allergens and administers this cocktail either under the skin or the tongue, depending on age and other factors. The benefit is usually obvious within a matter of days. 'Some patients may respond to simple neutralization with a cocktail of inhaled allergens and may need no further treatment. After about a year of neutralizing injections, they are normally completely desensitized. Other patients may become symptom-free on the elimination diet. Still others have both food and inhalant allergies and may need to be neutralized before they attempt an elimination diet. The most complicated of all are patients with both kinds of allergies who also have nutritional deficiencies of, say, magnesium, B6 or B12. These deficiencies can be determined by sweat tests, hair mineral analysis, red blood cell magnesium, etc, and vitamin B deficiencies, by function tests on blood specimens.'

We would only add that before undergoing desensitization or anything in which substances are injected into you, you might try other methods such as those outlined in WDDTY Alternatives, on asthma, vol 4 no 4. If they don't work, desensitization appears, at least at the moment, to be a safer option than the known dangers of asthma drugs like steroids (see our Case Study, p 10).