Food allergies happen when a person's immune system believes that something he or she ate is harmful to the body. In an attempt to protect the body, the immune system produces antibodies, called immunoglobulin E (IgE), to that food. Those antibodies then cause mast cells (allergy cells in the body) to release chemicals, one of which is histamine, into the bloodstream. The histamine then acts on a person's eyes, nose, throat, lungs, skin, or gastrointestinal tract and causes the symptoms of the allergic reaction.
Milk Allergen
Beta-Lactoglobulin is the major whey protein in ruminants and pigs. Human infants can develop an allergenic response to cow milk proteins. Beta-Lactoglobulin is the primary antigenic component that stimulates the immune hypersensitivity response in the infant. Symptoms are similar to lactose intolerance.
Small amounts of milk protein can pass through the breast milk and may cause allergic signs and symptoms in some infants. Cow's milk allergy (CMA) affects about 2-7.5% of infants.
Curds and Whey
The two main components are whey and casein, and an individual may be allergic to either or both. The casein is the curd that forms when milk is left to sour, and the whey is the watery fraction which is left after the curd is removed.
The whey proteins are altered by high heat, and so the whey sensitive person maybe able to tolerate evaporated, boiled or sterilized milk and milk powder. Goat's milk is tolerated by only 40% of children who are allergic to cow's milk.
Allergic reactions have been described according to 3 types. Usually reactions occur due to the intake of moderate to large amounts of cow's milk.
Type 1 - Symptoms start within minutes of intake of small volumes of cow's milk. Mainly causes skin problems, eczema or urticaria (hives). May involve respiratory (runny nose, wheezy chest) or gastro-intestinal (vomiting and diarrhea) symptoms.
Type 2 - Symptoms start several hours after intake of modest volumes of cow's milk; mostly symptoms of vomiting and diarrhea.
Type 3 - Symptoms develop after more than 20 hours, or even days after intake of large volumes of cow's milk. Symptoms include diarrhea, with or without respiratory or skin reactions.
With a doctor's supervision, removing milk products from a child's diet can help determine if illness is caused by it. Calcium supplements or other food products can be determined by a dietician to help make up for no milk. After all, milk may be present in in foods where you least expect it.
Most children will outgrow their cow's milk allergy. 40% at age 4 and 60% at age 6. Some may acquire the allergy later in life. Food intolerance is different from a food allergy. Lactose intolerance is quite common and may cause children to feel gassy, bloated and have diarrhea.
Egg Allergen
Hen's egg is one of the more frequent causes of food hypersensitivity in infants and young children. Studies have shown that Ovomucoid is a major allergen of egg white. Ovomucoid comprises 11% of egg white protein.
It has been demonstrated that Ovomucoid and not Ovalbumin, is the dominant antigen and allergen in egg white protein in human beings. It appears to be allergenic in minute quantities and because of its hardy physical characteristics, it may remain in the body in an allergenic state for years.
These properties make Ovomucoid a suitable marker protein for the presence of egg residues ( egg white) in food products.
People who have an egg allergy may experience anaphylaxis - a severe allergic reaction that causes swelling of the mouth, throat, and airways leading to the lungs, resulting in an inability to breathe. In addition, anaphylaxis causes a dangerous drop in blood pressure, which can make someone dizzy or pass out, and may quickly lead to shock. For people who are especially sensitive to eggs, the air fumes or getting egg on the skin can cause an anaphylactic reaction, so eggs should be kept out of the home completely.
Soy Allergen
Although the incidence of allergy to soybean proteins is quite low in comparison with other major food proteins, the gradually increasing consumption of soybean products makes the identification
and characterization of major soy allergens a focus of investigation. Delayed allergic responses to soy are less dramatic, but are even more common. These are caused by antibodies known as immunoglobulins A, G or M (IgA, IgG or IgM) and occur anywhere from two hours to days after the food is eaten.
Two soy proteins have been identified as antigenic. Soy belongs to the legume family, which include navy beans, kidney beans, string beans, black beans, pinto beans, chickpeas (garbanzo or chichi beans), lentils, carob, licorice and peanuts. Many people are allergic to more than one legume. If your doctor is unable to identify which soy product is causing your allergy, it is best to avoid them all.
Soy allergy is more common in infants. The average age at which the allergy manifests is 3 months but the majority of infants outgrow it by the age of two. Although adults do suffer from soy allergy, it is rare.
Symptoms of soy allergy are many and may include:
-Acne and other skin conditions, like eczema
-Swelling
-Nasal congestion
-Anaphylaxis
-Asthma
-Canker sores or fever blisters
-Colitis and other gastrointestinal problems, including diarrhea
-Conjunctivitis
-Shortness of breath
-Fever, fatigue, weakness and nausea
-Low blood pressure
-Itching
-Hay fever
-Hives
Some food products usually contain soy, or are manufactured on machines that may have soy residue on them. The way that the soybean is grown, harvested, processed, stored and prepared in the kitchen can all affect its allergencity. Hidden soy exists in thousands of everyday foods, cosmetics and industrial products such as inks, cardboard, paints, cars, and mattresses.
The majority of children with food allergies such as milk and egg are outgrown by the fifth birthday. However, peanut, tree nut, fish and shellfish tend to be life-long. These foods are also commonly associated with more severe allergic reactions.
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