Should an allergic person avoid Milk?
Cow's milk is not an uncommon allergen in infancy, probably because it is the major foreign protein food during the early months of life. It has been estimated that milk allergy occurs approximately in 0.5 percent of children. Milk allergy manifest itself by a variety of symptoms. The commonest symptom is that of the infant feeling unwell when he is put on a milk other than that of his mother, and a need is felt to change from one milk to another. Other symptoms pertain to alimentary tract and respiratory tract. There may also be eczema or urticaria. Whenever possible the infant should breast-fed. This reduce the chances of the development of allergic symptoms. Giving  cow's milk should be delayed up to the age of 9 months to a year in a potentially allergic child. 

Many a time, the diagnosis is missed because allergy to milk is not suspected. The best way to make a diagnosis is by eliminating milk from the diet and then rechallenging the process to administer antigen to evoke an immunological response. Milk must be eliminated from the diet for at least two weeks. If during this period there is marked improvement in the health of child, or when reintroduction of milk brings back the symptoms, the diagnosis is established. After the diagnosis is clinched, the offending milk must be removed from the diet. Milk prepared from soya beans is a good substitute. If it is not locally available, it can be prepared in the house. The soya bean milk should be given up to a year or so and then a re-trial could be made with the offending milk. If the child does not tolerate it, soya bean milk may continue to be given; if few symptoms appear then the cow's milk may gradually be added in the diet. Soya bean milk is as nutritious as mother's milk; however, this needs to be supplemented with vitamins and minerals.

Wheat Allergy
Next to milk, wheat is the commonest source of food allergy. This is detected when the infants for the first time is given cereal, and develops a rash, abdominal colic or diarrhoea. An older child or an adult may have asthma or a patch of eczema which is found to be improved by not taking wheat in any form. The treatment is avoidance of wheat in all its different preparations. 

Egg Allergy White of an egg is pure albumin ( a protein) and being a foreign protein, it is potent source of allergy. Taking of a raw egg by a person allergic to it, can cause a most severe reaction, including collapse and shock. Even the smell of egg's contents can cause allergic reactions in highly sensitive people.

Fish Allergy
Fish and other sea foods are amongst the most potent allergic agents. There is a cross reaction among various sea foods. Those who have reaction to fish should avoid other sea foods as well. Here again, even the smell of fish can produce urticaria in some people who are strongly allergic to it.

Other Food Items 
Most of the nuts, e.g. almond, walnut can cause allergic reactions. Persons who are allergic to them have to avoid them and also preparations like cakes and cookies containing nuts. Other food to which people are commonly allergic are: apples, bananas, cashew nuts, oranges, lemons, grapefruit, mushrooms, watermelons, cucumbers, grapes, gur (not cane-sugar), mustard, radish, onion, garlic, chocolates and soft drinks.

The difficulty arises when the offending food is either milk, egg or wheat, each of which is a common ingredient of many other foods so that its presence is not generally suspected by the patient. It is incumbent on the patient to study and know the ingredients of the food he consumes, so that, he may be better able to avoid any or all of these foods in his diet.

Skin test
Many  times, there is no correlation between the skin tests and the clinical trials with a food. This is because the tests are made with foods extracted in the raw state but eaten in the cooked state, and it has been shown that the cooking of some foods may denature them to the extent by the individuals sensitive to them. While food trials are being conducted, it is essential that all other treatment remains unchanged. The best method of treating food allergies is to find out the incriminating food and to avoid it. While eliminating one food, it is necessary that a non-allergenic substitute of equivalent food value be added to maintain nutrition and avoid monotony. Desensitization to foods is seldom resorted to. Where the offender cannot be identified, one can only depend on symptomatic therapy. Along with this the patient is advised to take, as far as possible, cooked foods which being denatured are less allergenic.

Diet for Asthmatic Patients 
Proper diet taken at regular times is very important for a patient of asthma. This can not only prevent an attack from occurring but also can lessen the severity of the attack that a patient is having. The diet should be light, nutritious and well balanced. It should not contain such things which do not go well with the patient. Experience shows that for north Indians, rice taken at night causes discomfort in breathing. This may be because of the fact that to satisfy hunger with rice, one has to take a large quantity of it, so that the stomach is blotted and this put hindrance in the way of the full and proper working of the diaphragm in respiration. Other things that patients generally complain of not being comfortable are taking bananas; among the vegetables ladyfingers and among the lentil, urad and its dal. So these may be avoided. Spices should be avoided in diet. With some people, cold drinks and sour preparations like chuttnies and pickle cause coughing; so these may be avoided.

Asthmatic patient should not take full-stomach meal. Fullness of stomach after meals in particular at night causes discomfort in breathing or even precipitates breathlessness. One should take less quantity at a time, though he may take for more numbers of times. Fried things should be avoided as far as possible.
 
No sweet dish would be taken at night. A patient of asthma would notice that he feels more comfortable during the night if at the time of sleep his stomach is not heavy. So dinner should be taken at least two hours before going to bed. Asthma patient should take a variety of vegetables, cheese, eggs and chicken , soups and fruits. But all of these should be taken in moderation. There should be adequate variety in the diet of the patient so that he does not feel bored with it. It is preferable that an asthma patient avoids taking food outside his house, particularly the party dishes; they are all heavy with fat and frying. However, in order to avoid attention towards oneself, one may, if it is possible, take lighter meal than usual with one or two innocuous looking dishes.

Diet for aged people 
In old age calorie requirement is reduced because of lessened activity and lowered metabolic rate. If such person is suffering from some other disease like arthritis or angina, the activity is further reduced. Aged asthmatic persons on corticosteroids occasionally or regularly, are on increased risk of developing osteoporosis (thinning of bones). Both old age and effect of steroid drug causes thinning of bone by inducing deficiency of calcium, protein, vitamins, minerals and hormones. It can cause fracture of bones even without significant trauma. It is not uncommon to find in an x-ray of the chest that one or more of the vertebrae are broken and collapsed. The whole body of an older asthmatic is shrunken- the height, the muscles, the girth of the abdomen.
 
In such patients special diet is important. Calorie content of the diet should be increased. When the patient feels better, he must be asked to take more diet so as to regain weight. Intake of proteins and vitamins such as milk, cheese, pulses, soyabean should be encouraged. If he is non-vegetarian, then he can add chicken or its soup, meat, egg and fish, provided he is not allergic to any of these. For the sake of variety in diet, custard, pudding can be taken, particularly so if mastication is the problem because of loss of teeth. Intake of fat should be limited. Anyone of the multivitamin tablets with mineral should be added to the daily diet.
Injections of one of the anabolic steroids are helpful in older people to regain protein retention; Some increase in weight and a general feeling of being energised is observed.