Asthma is a chronic disease with acute exacerbations. The nervous idiosyncrasy which is present in the subjects of this affection is usually accompanied by certain idiosyncrasies as regards diet. An attack may be precipitated by some article of food, not in itself indigestible to ordinary people, such as an egg, oatmeal, etc., or by some of those foods which more frequently induce gastric disturbance, such as pork or lobster. These peculiarities are common to asthmatic patients as a class, but the special peculiarity varies with the individual. In some of these cases the food may really act as a poison, and its toxic effects are manifested by an attack of asthma after absorption into the system. In other cases, however, the effect is produced so quickly, while the patient is still at the meal, that there appears to be some stomach reflex set up by a certain article of diet, which precipitates an attack. One cannot say beforehand what special article of food will induce asthma in an ordinary case, but when the sufferer has discovered this for himself, it is clearly indicated that he should avoid this food in the future.
Asthma is a disease which can be very greatly ameliorated but cannot be cured by diet. The asthmatic subject must be taught to regard his digestion, and the selection of suitable food, as of the first importance. The pleasures of the table are not for him. The treatment of a case will commence with the ordering of a diet of simple, wholesome, well-cooked food. Perhaps it is better to say what he should not take rather than what is to be allowed. In the forbidden list will be placed rich sauces, pastry, sweetened puddings, cooked butter, cheese, nuts, dried fruits, pickles, salmon, pork, sausages, and all re-cooked meats and made-up dishes, because of their liability to cause digestive disturbance. To this list will be added the stronger wines, such as port, sherry, and Burgundy, except in strictly limited amounts. There will also be included any article of food which tends to induce an attack, as observed by the patient himself. The aid of the sufferer must be obtained in watching the effect of this simple diet and noting any bad effects from special food materials. For it is only by close observation of each individual case that any correct conclusions can be drawn as to the effect of treatment. In some there will be found a difficulty with the digestion of proteins (meat more especially), in others with the carbo-hydrates (bread and puddings), and in others with the fats. This will lead in one case to the trial of a meat-free diet, and in another to a reduction in the carbo-hydrates or fats. The conclusion, however, must not be drawn that because one patient has definitely improved on a vegetarian diet that therein lies the chief hope for all sufferers from asthma. In the majority of cases the fault will be found to lie not in the food material, but in the idiosyncrasy of the patient. Gout is the underlying cause in many cases of asthma, and for these a special regimen may be required (vide Gout). At the same time one must not too readily ascribe every case of asthma to this origin, even if some of the patient's relatives or ancestors have had gout, or if the patient has been informed that he is suffering from " suppressed gout".
In addition to rendering the food suitable for the digestive powers of the patient one must also regulate the quantity at a meal, and the meal-times. A full meal will often precipitate an asthmatic attack, and if too much is taken at one time the breathing will almost invariably be affected. The patient must, therefore, be warned to avoid eating much at a time. Three moderate meals a day can be taken in many cases without disturbance, but in other cases it is advisable to order four meals a day, so as to avoid overloading the stomach. A heavy meal in the evening is especially apt to induce an asthmatic attack during some period of the night. The evening meal should be light and should be taken at least three hours before going to bed. A little fish or chicken or a cutlet, with one vegetable, and toast, followed by biscuits and butter, will supply the needed nourishment in a digestible form. The midday meal should be the most substantial one. Tea, coffee, and cocoa may be allowed to form part of the dietary, provided that they are not found to increase the difficulty of breathing.
In an acute attack the diet must be very limited and as digestible as possible. Fluids are preferably employed in the form of plain meat-soups, bread-and-milk, or milk and Benger's food. It is at this stage that a demand for stimulants is usually made by the patient, as he has experienced relief from whisky or brandy already supplied by the home authorities. There is no doubt that alcoholic drinks relieve an asthmatic attack, but this fact only makes their use the more dangerous. This is not the case of an attack of passing illness, but of a disease which tends to return, often with increased frequency. If alcoholic stimulation is prescribed, the tendency will be for the patient to resort to it whenever his breathing becomes troublesome. In but too many cases one finds that large amounts of alcohol are consumed by the sufferer from asthma, and that in time he becomes a confirmed tippler, on the ground that he cannot get on without regular alcoholic stimulation. For these reasons, and considering the responsibility of the medical adviser, it is probably wiser not to order alcohol in any form for the relief of asthma. Other means, unattended by the same risks, can be employed, such as strong tea or coffee, and various drugs. In chronic cases it is not necessary to forbid the lighter alcoholic beverages, such as beer, Hock, or claret, provided the patient has been in the habit of taking them in moderation and without harm to his digestion. It is never wise to order them, or to approve of their being taken, to the extent of marked stimulation.