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FOOD ALLERGY
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The most common type of food allergy is the Type I. This is due to histamine release from mast cells. This leads to inflammation and increases vascular permeability. Food molecules can pass though the intestinal wall into the circulation. Patents who have food allergy can have IgE antibodies besides IgG and IgM. Hypoallergenic diet is sometimes helpful and is therefore advised . Certain children may get benefit from well-defined unprocessed types of meals such as potatoes, carrots, cooked apples, olive oil and soya milk. Another types of food that may be of help are, rice, rice flour, cabbage, rhubarb, margarine and lamb meat. These types may be prepared and used as subsitute for the blamed diet. Breast milk is the best and the natural feeding for infants. There is no type of food, which can be considered as a substitute for breast milk if the mother can and have the ability to pump it regularly for her baby. Food hypersensitivity occurs most in infants and young children due to escape of food antigens from the gut into the circulation. Infants especially those born to atopic parents should depend only on breast milk at least in the first 6 months. Breast milk is believed to have certain factors which can seal the infants gut mucosa, thus reducing antigen access to the circulation. Breast milk protects against gastro-intestinal infections and infantile colitis. Certain type of food can cause periodic migraine that may be due to inability of the brain tissue to break down dietary amines because of the selective enzyme deficiency. Different types of food such as cow milk; eggs, seafood, cereals, chocolate and many others may cause an allergic reaction. Food allergy should not be confused with food intolerance. Food intolerance may be immediate after ingesting the suspected food or delayed. The role of food in causing or exacerbating eczema varies from one case to another. Different gastrointestinal and allergic reactions are attributed to an abnormal allergic response to foods. Food proteins are the most common such as that of egg white and milk. Cereals, milk, certain types of juices such as orange, mango may act as important allergens. If food allergy contributes to exacerbation of atopic dermatitis, the relevant antigens must penetrate the intestine and reach the skin, or can activate lymphoid cells or basophiles that subsequently infiltrate the susceptible skin. The possible occurrence of a transient IgA deficiency may have also an effect. Any defect in IgA concentration increases the likelihood of penetration by food antigens and the possibility of allergy. Another possible association between food allergy and atopic eczema is a more general, non-immunologically controlled factor or increased permeability of the intestinal mucosa. The relation of food to eczema may be due to different factors mainly: Histamine - Histamine is liberated from egg white, cheese, strawberries, fish or canned food. Tyramine: this may be due to some types of food such as yeast and cheese. Caffeine: is found in coffee, tea, cola drinks, cocoa and chocolate. Tartrazine: This is a food coloring azodyes material, which is widely used in industry of food and drinks. Tartrazine is a brilliant orange yellow dye used in fruit and medicine industry. This material may cross react with aspirin and azodyes. Herbal drinks, Karaya, tragaganth in gums can produce also skin reactions.
Salicylates: Salicylates are available in natural foods such as citrus fruits, apples, banana, grapes, strawberries, vinegar and liquorice or in additives to certain foods such as ice cream, chewing gum, jam, jelly and soft drinks. Salicylates in food or drugs may provoke severe angioedema and asthma. Nitrates: this is available in preserved foods. Glutens: Glutens are present in wheat, corn, barley, oats and rye. Coeliac disease due to gluten intolerance may not be diagnosed for many years due to immunological abnormalities. Circulating antigliadin and antireticulin antibodies can be detected in some patients. Glutens damage the lining of the small intestine leading to mal-absorption of food, manifesting with diarrhea, failure of growth, loss of weight, anemia and bone diseases.
Recovery from these symptoms is usually rapid on using gluten free diet. Milk Idiosyncrasy to milk: lactase deficiency will lead to intolerance to cows milk. Cows milk mainly affects babies under bottle-feeding manifesting with vomiting, diarrhea, colic and eczema. Milk substitute instead of cow‘s milk is soya beans, goats or sheep‘s milk. Cow milk or Soya bean ingested allergens has an important role to exacerbate the allergic reaction in patients with atopic dermatitis particularly in children. These reactions may be due histamine release and other vasoactive amines. Toxic products: toxins are available in certain types of food such as that of the poisons of tropical sea fish. Clinical manifestations of Food Allergy Allergic reaction to food may occur immediately after ingesting a certain type of food or delayed for a shorter or longer period.
Manifestations of immediate allergic reaction Immediate reaction includes: Swelling of the lips and tongue. Urticaria which may be generalized. Gastro-intestinal manifestations such as vomiting, diarrhea and abdominal colic. Respiratory manifestations such as asthma may be predisposed by certain types of food. Allergic manifestation may fellow immediately after taking certain type of food due to direct effect on the oral mucosa or an IgE mediated reaction. This type of reaction occurs within a short time after ingesting the blamed food stuff such as whole protein in milk, eggs, peanut, fish, shellfish, strawberry, chocolate, nuts, tomatoes and whole wheat as cereal and brown bread. Manifestations of delayed allergic reaction The allergic reaction varies on different factors mainly; age, type, amount of sensitizer and the susceptibility of the patient. Skin manifestations occur several hours or even after few days later due to a break down products of the whole protein. These types of allergens cannot produce an immediate reaction where repeated ingestion of such types of food can elicit enough antibodies to produce an allergic reaction. Such sensitizers may be milk, chocolate, eggs, cola, orange, tomato, corn wheat, food coloring and peanuts. Gastro intestinal manifestations: Vomiting, regurgitation of food in infants. Colic, diarrhea, constipation, in the form of irritable bowel syndrome. Steatorrhea, protein loosing enteropathy and cows milk sensitivity enteropathy. Skin manifestations: The skin lesions may be an eczematous reaction, urticaria, and angioedema. The severity of the reaction depends on different factors mainly the type of the food causing sensitization and the susceptibility of the patient. When there is an allergy to a special type of food, there is exacerbation of the previous skin lesion and one or more other allergic reactions may manifest as urticaria, angioedema, asthma and rhinitis. Urticaria or angioedema may be due to food or beverages containing food additives such as tartrazine and salicylates. Cows milk and eggs may cause eczema. Complex foodstuffs may cause asthma, rhinitis, migraine, coeliac diseases and irritable bowel syndrome. Therefore strict regime of diet exclusion may be indicated to specify the blamed type of foodstuff. Foods to be excluded can cause exacerbation of the allergic reaction when the patient is re-exposed again to such type of food. Mucous membrane manifestations Swelling of the lips, oral irritation or ulceration and pruritus ani. Other symptoms: systemic reactions as asthma, rhinitis, and migraine. Hyperactivity in children, migraine and painful joints may accompany food allergy. Different foodstuffs that may cause eczema It is not always easy to identify the offending foodstuffs. Trying to remove these from the infant‘s diet is of a great help in controlling the allergic reaction. It should be noted that patients may react to more than one type of foodstuff and at the same time one type of food may contain several ingredients that each may cause food allergy. Bread for example may contain wheat, milk, Soya and yeast, where each of these may act as a triggering factor causing or exacerbating the allergic reaction. Different types of food and additives, which may exacerbate skin lesions: Meat: Preserved meats, sausages, salami, dry meat and luncheon meat with spices or olives. Other fresh meats can be used. Fish: Smoked fish, shell fish, canned fish should be avoided. Although white fish can be allowed, yet some cases of eczema exacerbate with any type of fish whether fresh or a preserved type. Cereals: different types of food stuffs prepared from wheat, oats, barley, rye, corn as in cerelac, biscuits, cakes, baking powder or others containing corn in one form or another, as corn starch, oil, syrup or corn meal can cause eczema. Starch, maize oil, glucose syrup, bottled sauces may contain starch. Canned foods as soups, puddings, baked beans, corn flakes, custard, ice creams, jams, margarine, vegetable oil and dextrose are other foodstuffs that usually contain corn.
SUBSITUTES
OF AN ALLERGENIC FOOD Soya milk can be used as a substitute for milk. Soya milk can be prepared by mixing 150g/ 5 onz Soya flour with 1.5 pints with water in a saucepan and heated slowly while stirring till the boiling point and then reduce the heat gradually stirring for 20 minutes. Flavor can be added as apple juice when the milk is cold or honey can be also added. This can be stored in the refrigerator to be used later on as milk substitute. For older children the following meals may be tried for cases of eczema exacerbated by food: Breakfast: Fruit juice, milk substitute such as that used for infants as Soya emulsion. Children can be given toast, marmalade. Lunch: Pancakes, mixed salads, baked bananas and nut cream. Supper: Potatoes, carrots, fruits, chestnut soups, whole meal rolls, turkey, apple and cherries.
Breakfast: Fruit juice, milk, grilled lamb and tomato, whole meal bread, butter and yeast extract. Lunch: Chicken, rice, stuffed baked apples. Supper: meat with white toast, white fish, Spanish, potatoes, fruits. Other types of meals, which can be suggested for the patients. Breakfast: Apple juice, milk substitute, rice crackers with margarine. Apple, banana can be included in the breakfast meal. Lunch: Sheep's yogurt, fruit salad, and green salad. Supper: Fruit cocktail, lamb meat, millet and carrots. Exclusion of diet: To eliminate the special type of diet which is suspected as a causative of an allergic reaction or exacerbating the existing lesion. How to plan for exclusion of the offending diet causing exacerbation of eczema is very important. The role of the attending physician is to explain to the infant‘s mother the way that can help to spot the blamed food and later to be eliminated. Follow up The symptoms that the infant or child is complaining of should be recorded in a notebook. Strict elimination of blamed food The patient is kept strictly on one of the food substitutes for two weeks. The child should be kept strictly on this type of food and if the mother feels that no abidance as by eating some of the suspected food, she has to start again from the beginning. If this is applied strictly usually the skin lesions begin to improve. Food testing The mother begins to add on the third week one of the excluded diet and record that on the diary, meanwhile watching her child for two to three days while he is using this foodstuff. She can begin with cows milk, cereals, rice, corn, wheat, eggs, lamb meat, chicken, white fish, potato, banana, citrus fruits and each of these is given to the child in order for three or four days and watching her child thoroughly not to use any restricted diet with this regime. If the skin lesion is exacerbating again, this means that this type of food is usually considered as an offending agent and should be excluded. If no exacerbation of the skin lesion after adding this type of food, this means that this type of food can be taken. It should be noted that the reaction due to food is not always immediate. After ingesting the foodstuff, it may appear after a few hours or days. Meanwhile, plenty of the tested food should be taken daily for about three or four days. After that date, if there is no change in the skin lesion or no reaction in normal infants, this type of food may be considered non allergenic to the infant or child. Some type of foods contain more than one ingredient where each may act a possible triggering factor. It is of prime importance to test each ingredient purely alone as testing yeast before bread or rye bread. Some medications such as aspirin or paracetamol contain wheat and starch besides the active material. Using plain chocolate can test chocolate. Cows yogurt to be tested as natural yogurt with no flavor or fruits or other ingredients added. Detection of other sensitizing food If the symptoms are not improving after two weeks in spite of the strict diet exclusion, this means that the food is not the cause of the skin problem. There is no need for any food restriction, in this case another factor is working and exacerbating the condition. Exclusion of the suspected type of food is in need of great patience and good well and if followed in the proper way, it will be of very much help. If there is allergy to different types of food and the picture of testing becomes hazy and you cannot reach a precise data, you can try testing group of foods to gather daily. The following foodstuffs can be tried: In the first day: Soya beans emulsion alone for the infant or rice, poultry, carrots for older age groups. In the second day: banana, potato, and beefs. In the third day: rice, white fish, potato, and apples. In the fourth day: lamb, tomato, and green beans. In the fifth day: yogurt, egg, pasteurized goat milk (care should be taken that such milk is free from salmonella, brucellosis and TB contamination), so it should be pasteurized and kept in the refrigerator. Powdered goat milk can be used if available, where most powdered milk in the market is cow‘s milk. Follow the exclusion regime, taking into consideration that this should include the normal requirements for the infant or child. Dietician may be consulted to arrange palatable and balanced diet for such groups having food allergy. Sometimes vitamins are needed especially the fat soluble ones (A, D, E, K). These vitamins should not contain wheat starch during their manufacture and should be given cautiously abiding with daily requirement of the infant or child. The daily requirement of vitamins is;
For infants and children the best source for vitamin D is sunshine. Keep the infants free from diaper and clothing and expose them to direct sunlight for a few minutes daily, preferably in the morning . Desensitization Therapy Desensitization has been found to be beneficial in treatment of some cases of atopic dermatitis, hay fever, asthma and in some cases of food allergy in children and older age groups.
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