Once one has been diagnosed as having a particular food allergy, life is not over. On the contrary, a new life can begin when one knows the foods that are safe to eat —and the ones that are not.

When the exact cause of the food allergy remains unknown after all diagnostic tests have been completed, your doctor may prescribe drugs to alleviate the symptoms. (Unfortunately, such drugs cannol cure the allergy itself.) Another approach is the rotary diet, in which no food is repeated within a five-day span, thus reducing symptoms.

Anyone with a tendency to allergy generally c an be, or become, sensitive to one or more foods. The tendency to allergy is inherited it can show up in any symptoms of allergy, and any substance са n become the sensitizer, including foods. A child has a 75 регсе nt chance of developing an allergy at an early age if both his parents are allergic. Although food allergy can occur at just about any age, it is most likely to appear during infancy. As children grow older, their food allergies often change; such children may develop an allergy to a new food, or lose an existing allergy. Most food allergies, however are outgrown.

After you have avoided the offending foods for at least six months, you may, if your doctor approves, try a small amount of the food. If the symptoms do not recur, you may be able to take a little of the food on occasion. People experiencing severe immediate reactions to certain foods, such as eggs, shellfish, nuts, buckwheat, or mustard, often will do so for the rest of their lives. No food causing severe allergic symptoms should ever be eaten at any time, in any amount. This requires ex­treme diligence and scrutiny on the part of the patient, particularly when dining away from home. Tasting only a tiny amount of the food before considering it safe to eat is a good habit to get into in this type of situation. Even this, however, is not always totally safe. Because the content of a food cannot always be known ahead of time, allergy patients who must eat away from home should carry Adrenalin or another prescribed drug if an allergic food is inad­vertently eaten.

Although food allergy was first studied scientifically only half a century ago, the Egyptians, Chinese, Jews, Greeks, and Romans of antiquity were aware that, as Lucretius observed over 2,100 years ago, "One man’s meat is another man’s poison." Some biblical scholars believe the Old Testament’s dietary restrictions reflected, in many instances, an awareness that certain foods caused severe symptoms in some people. Food allergy is a specific food hypersensitivity that develops when the offending (allergenic) substance happens to be a food. The symptoms that develop after eating a certain food or foods can involve the skin, the nasal passages, the respiratory or gastrointestinal tract, and very rarely the entire circulatory system. There are two major types of allergenic reaction to foods : immedi­ate and delayed. The immediate reaction is often violent and some-times life-threatening. The symptoms appear within minutes after the food j,as been eaten, and sometimes even before it is swallowed. This is particularly true of patients allergic to shellfish, nuts, and eggs. On the other hand, delayed reactions to foods are subtler, as it may be many hours before the symptoms appear. Thus, it is much more difficult for patients to associate their symptoms with a particu lar food substance. It is generally believed that in the immediate reaction the offending food is the whole protein while in the delayed reaction some substance formed during the digestive process is involved.

Until the last few years, food additives were considered safe, or at least insignificant in normal doses. Today, such additives are suspected of being responsible for reactions similar to those attributed to food allergy. Additives are synthetic chemicals that add color, taste, and texture to such foods as candies, gelatin desserts, mustard, and canned goods. Unfortunately, because some additives are used so widely and labeled inaccurately, it is often difficult to avoid them. A reaction to food ad ditives is probably not caused by allergies, h rather by a toxic reaction to some substance in the additive. С It is sometimes claimed that food additives are responsible for some psychoneurotic and hyperactive behavior in children.) Hives, asthma rhinitis, and constipation are a few of the possible reactions to additives that may seem to be caused (as they often are) by a food allergy. What is the most effective treatment of food allergy? Once the offending foods have been discovered, the most effective treatment is simply to eliminate them from the diet.

The term vegetable gum encompasses members of twelve different botanical families. An allergy to one gum, therefore, does not necessarily mean that the person is allergic to all gums. He or she must find out which specific gum causes the allergic reaction. Because vegetable gums are inexpensive, they are used extensively in commercial foods as fillers and binders. They also retard melting in frozen foods. Different gums have different properties, and each is used for its own individuality in different types of products. Inhalation of dried flakes of vegetable gum can cause respiratory symptoms in a gum-sensitive person (for example, while combing hair after using setting lotion con­taining gum) . Eating the gum can cause any type of allergic reaction. Cheseborough-Pond’s, a major cosmetic manufacturer, advises that when natural gums are used, a preservative, germicide, or fungicide must be added to the product to prevent deterioration of the gum. For this reason, synthetic gums are replacing natural gums in order to achieve longer shelf life for cosmetics. Some manufacturers of surgical tape use acrylic resin adhesive, and others use syn­thetic rubber and resin mixture.

Even if one or more of the symptoms associated with food allergy is present, a food allergy may not be responsible. The same symptoms may be caused by food spoilage or contamination, by the method of cooking or feeding, by the body’s lack of an enzyme or some other digestive factor, or simply by digestive intolerance. Other causes are internal diseases involving the stomach, gall bladder, intestines, and pancreas, as well as fatigue, stress, drugs, and emotional problems. Once these possibilities have been ruled out, the food allergy patient is ready for a rigorous diagnostic process, the first step of which is a careful history. This may be followed by skin testing. Unfortunately, however, although such tests are reliable in diagnosing allergies to dust, pollen, or pets, they are less so in diagnosing the specific cause of a food allergy. Test extracts made from food tend to lose their potency fairly quickly; they often fail to provoke a skin reaction in case of proven sensitivity. Though the tests may be positive in people experiencing immediate reactions to allergenic foods, they are considered, in many cases, to be without clinical significance. Skin tests are even less reliable among patients experiencing the 1 delayed type of reaction, as the test extract contains only the whole food and no digested material—though the latter is usually involved in this kind of reaction. Another testing method involves placing diluted food extracts under the tongue, but this method is also considered unreliable and is often omitted. Treatment by administering extract solutions j under the tongue is also not a warranted method. A trial diet is the most effective procedure known for determining the specific food or foods to which a patient is allergic. On the first day, the patient eats the suspected offending food in all forms and in substantial quantities, provoking an allergic response. Then, for the next five days, the suspected offending food is avoided totally, which should result in an absence of symptoms. On day seven, the suspected offending food is again eaten, on an empty stomach, and in its pure form (that is, for example, a glass of milk, but not cheese or ice cream). The pattern of reaction and nonreaction will either be significant enough to eliminate all doubt about the effect of the food or the suspected food will be eliminated from consideration as the cause of the allergic reaction. What testing methods are used when the patient has no idea what food he or she is allergic to? Two general procedures are resorted to in this case : 1. Symptoms that occur only once in a while may be caused by infrequently eaten foods. A food allergy patient can sometimes help to determine the offending food by keeping a "food diary" in which each food eaten, the time of day, and any symptoms noted, are set down. Any medicines taken orally and any known exposure to environmental pollutants must also be recorded. A sample food diary is reproduced below. To determine the offending food, those foods that are believed to produce symptoms are checked individually by eliminating them from the diet for a week and then eating them in substantial amounts. 2. When symptoms occur every day, a special elimination diet, including at first only foods seldom found to cause allergy, may be prescribed. One by one, suspect foods are then added to the diet. When the symptoms occur regularly after a specific food is eaten, that food must be eliminated from the patient’s diet.

Food allergy symptoms can involve specific organs and systems! of the body and sometimes every organ and system. In the respira tory system, food allergy can cause asthma (manifested by coughing and wheezing) and such nasal symptoms as itching, runny nose, sneezing, snorting, and phlegm in the throat. Diarrhea, nausea, о r vomiting, and bellyache or cramps (colic in infants) may develop when food allergy affects the digestive system. Any area of the body may be subjected to swelling (edema), in- eluding the eyes, lips, face, and tongue. If the swelling develops in the throat and upper windpipe, breathing can be seriously impaired and suffocation may result. Eczema, a chronic skin disease, can some times also be caused by food allergy, and a rash may form in the bends of the arms and possibly all over the body. Food allergy can also cause fluid to develop behind the eardrums, which may result in intermittent deafness. Other symptoms sometimes caused by food allergy are migraine headaches, a mottled tongue, and canker sores in the mouth. It has been suggested, although not yet proved, that hyperactivity, irritability, and aggressiveness in chil dren may also result from food allergy. Immediate reactions to food affecting the throat and respiratory passages are particularly dangerous. Patients experiencing shock in response to an allergenic food usually develop severe nausea, vomit­ing, hives, and swellings all over the body and may collapse. These

Food contaminants, including pesticides, may be present in certain foods and can be misleading when one is evaluating allergic reactions. Thus, patients who drink milk that contains penicillin —used to treat cow udder infections—and who are allergic to the drug, develop an allergic reaction to the drug and not to the food, though the latter may appear to be the allergen. On occasion, a fish allergy may be mistaken for a milk allergy; milk may contain traces of fish protein present in cow feed.