Food allergy

Food allergy is an immune system response to a food that the body mistakenly believes is harmful. Once the immune system decides that a particular food is harmful, it creates specific antibodies to it. The next time the individual eats that food, the immune system releases massive amounts of chemicals, including histamine, in order to protect the body. These chemicals trigger a cascade of allergic symptoms that can affect the respiratory system, gastrointestinal tract, skin, or cardiovascular system. 
== The difference between food allergy and food intolerance ==
Many people think the terms food allergy and food intolerance mean the same thing, however, they do not:
* Food intolerance is an adverse food-induced reaction that does not involve the immune system. Lactose intolerance is one example of a food intolerance. A person with lactose intolerance lacks an enzyme that is needed to digest milk sugar. When the person eats milk products, symptoms such as gas, bloating, and abdominal pain may occur.
* Food allergy occurs when the immune system reacts to a certain food. The most common form of an immune system reaction occurs when the body creates immunoglobulin E (IgE) antibodies to the food. When these IgE antibodies react with the food, histamine and other chemicals (called "mediators") cause hives, asthma, or other symptoms of an allergic reaction.
== Symptoms ==
Symptoms range from a tingling sensation in the mouth, swelling of the tongue and the throat, difficulty breathing, hives, vomiting, abdominal cramps, diarrhea, drop in blood pressure, and loss of consciousness to death. Symptoms typically appear within minutes to two hours after the person has eaten the food to which he or she is allergic.
Symptoms of food allergies include:
* Anaphylaxis: a severe, whole-body allergic reaction that can result in death 
* Angioedema: swelling, especially of the eyelids, face, lips, and tongue
* Eczema
* Hives
* Itching of the mouth, throat, eyes, skin, or any area
* Nausea, vomiting, diarrhea, stomach cramps, or abdominal pain
* Runny nose or nasal congestion
* Wheezing, scratchy throat, shortness of breath, or difficulty swallowing
* Mood swings, depression
== Treatment ==
Strict avoidance of the allergy-causing food is the only way to avoid a reaction. Reading ingredient labels for all foods is the key to maintaining control over the allergy. If a product doesn't have a label, allergic individuals should not eat that food. If a label contains unfamiliar terms, shoppers must call the manufacturer and ask for a definition or avoid eating that food.
Epinephrine, also called adrenaline, is the medication of choice for controlling a severe reaction. It is available by prescription as a self-injectable device.
Currently, there are no medications that cure food allergies. Strict avoidance is the only way to prevent a reaction. Most people outgrow their food allergies, although peanuts, nuts, fish, and shellfish are often considered lifelong allergies. Some research is being done in this area and it looks promising.
== Common food allergen ==
Allergen is any substance (antigen), most often eaten or inhaled, that is recognized by the immune system and causes an allergic reaction. Virtually any food can be a food allergen. These food products comprised 90% of food allergy cases in USA: milk, egg, peanut, tree nut (walnut, cashew, etc.), fish and shellfish, soy, and wheat.
=== Milk ===
Fortunately, milk is one of the easiest ingredients to substitute in baking and cooking. It can be substituted, in equal amounts, with water or fruit juice. For example, substitute 1 cup milk with 1 cup water.
==== Some hidden sources of milk ====
* Deli meat slicers are frequently used for both meat and cheese products.
* Some brands of canned tuna fish contain casein, a milk protein.
* Many non-dairy products contain casein (a milk derivative), listed on the ingredient labels.
* Some meats may contain casein as a binder. Check all labels carefully.
* Many restaurants put butter on steaks after they have been grilled to add extra flavor. The butter is not visible after it melts.
==== Commonly asked questions ====
* Is goat milk a safe alternative to cow milk? Goat's milk protein is similar to cow's milk protein and may, therefore, cause a reaction in milk-allergic individuals. It is not a safe alternative.
* Can I rely on kosher symbols to determine if a product is milk-free? The Jewish community uses a system of product markings to indicate whether a food is kosher, or in accordance with Jewish dietary rules. There are two kosher symbols that can be of help for those with a milk allergy: a "D," or the word "dairy," on a label next to "K" or "U" (usually found near the product name) indicates presence of milk protein, and a "DE" on a label indicates the product was produced on equipment shared with dairy. If the product contains neither meat nor dairy products it is "pareve" (parev, parve). Pareve-labeled products indicate that the products are considered milk-free according to religious specifications. Be aware that under Jewish law, a food product may be considered pareve even if it contains a very small amount of milk. Therefore, a product labeled as pareve could potentially have enough milk protein in it to cause a reaction in a milk-allergic individual.
* Do these ingredients contain milk? These ingredients do not contain milk protein and need not be restricted by someone avoiding milk:
** Calcium lactate
** Lactic acid (however, lactic acid starter culture may contain milk)
** Calcium stearoyl lactylate
** Oleoresin
** Cocoa butter
** Sodium lactate
** Cream of tartar
** Sodium stearoyl lactylate
=== Egg ===
For each egg, substitute one of the following in recipes. These substitutes work well when baking from scratch and substituting 1 to 3 eggs.
* 1 tsp. baking powder, 1 T. liquid, 1 T. vinegar
* 1 tsp. yeast dissolved in 1/4 cup warm water
* 1 1/2 T. water, 1 1/2 T. oil, 1 tsp. baking powder
* 1 packet gelatin, 2 T. warm water. Do not mix until ready to use.
==== Some hidden sources of egg ====
* Eggs have been used to create the foam or milk topping on specialty coffee drinks and are used in some bar drinks.
* Some commercial brands of egg substitutes contain egg whites.
* Most commercially processed cooked pastas (including those used in prepared foods such as soup) contain egg or are processed on equipment shared with egg-containing pastas. Boxed, dry pastas are usually egg-free, but may be processed on equipment that is also used for egg-containing products. Fresh pasta is sometimes egg-free, too. Read the label or ask about ingredients before eating pasta.
==== Commonly asked questions ====
* Can an MMR Vaccine be given to an individual with an egg allergy? The recommendations of the American Academy of Pediatrics (AAP) acknowledge that the MMR vaccine can be safely administered to all patients with egg allergy. The AAP recommendations have been based, in part, on overwhelming scientific evidence supporting the routine use of one-dose administration of the MMR vaccine to egg-allergic patients. This includes those patients with a history of severe, generalized anaphylactic reactions to egg.
* I've heard the flu vaccine contains egg, is this true? Yes, influenza vaccines usually contain a small amount of egg protein.
* Is a flu shot safe for an individual with an egg allergy? Influenza vaccines are grown on egg embryos and may contain a small amount of egg protein. If you or your child is allergic to eggs, speak to your doctor before receiving a flu shot.
* Can someone who is allergic to eggs have a flu shot? Scientists suggest individuals with egg allergy be given an allergy test with the vaccine. If the test results are negative, the vaccine may be given in a single dose. If the test results are positive, individual assessment of benefits versus risk should be discussed with a doctor.
* Because of a family history of allergy, I have been advised to delay the introduction of egg until my child is 2 years of age. Does this mean my child should not be given the flu shot? Children under 23 months of age may be at higher risk for complications from influenza and are a group that typically require more hospitalizations from this sometimes fatal disease. You and your child's doctor should discuss the options. The general guideline is to follow the current CDC recommendations regarding the administration of the influenza vaccine to infants 6 to 23 months of age, unless the infant has a known clinical history of egg allergy.
* Is an intranasal influenza vaccine an option for someone with an egg allergy?
The intranasal vaccine contains egg protein, and it not recommended for use in individuals with egg allergy. It is approved for use in persons ages 5 to 49 years, but it is not approved for use in patients with asthma.
=== Peanut ===
==== Some hidden sources of peanuts ====
* Artificial nuts can be peanuts that have been deflavored and reflavored with a nut, such as pecan or walnut. Mandelonas are peanuts soaked in almond flavoring.
* Arachis oil is peanut oil.
* African, Chinese, Indonesian, Mexican, Thai, and Vietnamese dishes often contain peanuts or are contaminated with peanuts during the preparation process. Additionally, foods sold in bakeries and ice cream shops are often in contact with peanuts.
* Many brands of sunflower seeds are produced on equipment shared with peanuts.
==== Commonly asked questions ====
* Can peanut allergy be outgrown? Although once considered to be a lifelong allergy, recent studies indicate that up to 20 percent of children diagnosed with peanut allergy outgrow it.
* Can alternative nut butters (i.e., cashew nut butter) be substituted for peanut butter? Many nut butters are produced on equipment used to process peanut butter, therefore making it somewhat of a risky alternative. Additionally, most experts recommend peanut-allergic patients avoid tree nuts as well.
==== Keep in mind ====
* Studies show that most allergic individuals can safely eat peanut oil (not cold pressed, expelled, or extruded peanut oil - sometimes represented as gourmet oils). If you are allergic to peanuts, ask your doctor whether or not you should avoid peanut oil.
* Most experts recommend peanut-allergic patients avoid tree nuts as an extra precaution.
* Peanuts can be found in many foods and candies, especially chocolate candy. Check all labels carefully. Contact the manufacturer if you have questions.
* Peanuts can cause severe allergic reactions. If prescribed, carry epinephrine at all times.
=== Tree nut (walnut, cashew, etc.) ===
==== Some hidden sources of tree nuts ====
* Artificial nuts can be peanuts that have been deflavored and reflavored with a nut, such as pecan or walnut. Mandelonas are peanuts soaked in almond flavoring.
* Mortadella may contain pistachios.
* Tree nuts have been used in many foods, including barbecue sauce, cereals, crackers, and ice cream.
* Kick sacks, or hacky sacks, bean bags, and draftdodgers are sometimes filled with crushed nut shells.
==== Commonly asked questions ====
* Should coconut be avoided by someone with a tree nut allergy? A coconut is the seed of a drupaceous fruit. Coconuts are not typically restricted in the diet of an individual allergic to tree nuts. Some people have reacted to coconut; therefore, you should discuss this with your doctor before introducing coconut to your diet.
* Is nutmeg safe? Nutmeg is obtained from the seeds of the tropical tree species Myristica fragrans. It is safe for an individual with a tree nut allergy.
* Should water chestnuts be avoided? The water chestnut is not a nut; it is an edible portion of a plant root known as a "corm." It is safe for someone who is allergic to tree nuts.
==== Keep in Mind ====
* Tree nuts can cause severe allergic reactions. If your doctor has prescribed epinephrine, be sure to always carry it with you.
* Most experts advise tree nut-allergic patients to avoid peanuts as well.
* Most experts advise patients who have been diagnosed with an allergy to specific tree nuts to avoid all tree nuts.
=== Fish and shellfish ===
Allergic reactions to fish and shellfish are commonly reported in both adults and children. It is generally recommended that individuals who have had an allergic reaction to one species of fish, or positive skin tests to fish, avoid all fish. The same rule applies to shellfish. If you have a fish allergy but would like to have fish in your diet, speak with your allergist about the possibility of being tested with various types of fish.
==== Some hidden sources of fish ====
* Caponata, a traditional sweet-and-sour Sicilian relish, can contain anchovies.
* Caesar salad dressings and steak or Worcestershire sauce often contain anchovies.
* Surimi (imitation crabmeat) contains fish.
==== Commonly asked questions ====
* Should carrageenan be avoided by a fish- or shellfish-allergic individual? Carrageenan is not fish. Carrageenan, or "Irish moss," is a red marine algae. This food product is used in a wide variety of foods, particularly dairy foods, as an emulsifier, stabilizer, and thickener. It appears safe for most individuals with food allergies. Carrageenan is not related to fish or shellfish and does not need to be avoided by those with food allergies.
* Should iodine be avoided by a fish- or shellfish-allergic individual? Allergy to iodine, allergy to radiocontrast material (used in some lab procedures), and allergy to fish or shellfish are not related. If you have an allergy to fish or shellfish, you do not need to worry about cross reactions with radiocontrast material or iodine.
==== Keep in mind ====
* Fish-allergic individuals should avoid fish and seafood restaurants because of the risk of contamination in the food-preparation area of their non-fish meal from a counter, spatula, cooking oil, fryer, or grill exposed to fish.
* Fish protein can become airborne during cooking and cause an allergic reaction.
* Some individuals have had reactions from walking through a fish market.
* Allergic reactions to fish and shellfish can be severe and are often a cause of anaphylaxis.
=== Soy ===
Soybeans have become a major part of processed food products in the United States. Avoiding products made with soybeans can be difficult. Soybeans alone are not a major food in the diet but, because they're in so many products, eliminating all those foods can result in an unbalanced diet. Consult with a dietitian to help you plan for proper nutrition.
==== Keep in mind ====
* Soybeans and soy products are found in baked goods, canned tuna, cereals, crackers, infant formulas, sauces, and soups.
* At least one brand of peanut butter lists soy on the label.
* Studies show that most soy-allergic individuals may safely eat soybean oil (not cold pressed, expeller pressed, or extruded oil). If you are allergic to soy, ask your doctor whether or not you should avoid soy oil.
==== Soy free recipe ====
Stir-Fried Orange Beef
===== Ingredients =====
* 1 tsp. cornstarch
* 1 cup orange juice
* 1 to 1 1/2 lbs. trimmed beef, thinly sliced
* 1 to 2 T. of oil
* 1/4 to 1/2 tsp. crushed red pepper flakes
* 1 clove minced garlic
* 1 T. grated fresh gingerroot
* 1/4 cup green onion, thinly sliced
* 1/4 cup bell pepper, thinly sliced
 
===== Method =====
# In small bowl, combine cornstarch and orange juice. Set aside. 
# In wok, add beef, oil, and red pepper flakes. 
# Stir-fry over high heat until beef is browned. Remove beef with slotted spoon. Set aside. 
# Add garlic, gingerroot, onion, and bell pepper to oil remaining in the wok. #Stir-fry 2 minutes. 
# Add cornstarch/orange juice mixture. 
# Simmer until thickened. 
# Add beef and toss with sauce. 
# Can be served over noodles or rice.
=== Wheat ===
When baking with wheat-free flours, a combination of flours usually works best. Experiment with different blends to find one that will give you the texture you are trying to achieve.
Try substituting 1 cup wheat flour with one of the following:
* 7/8 cup rice flour
* 5/8 cup potato starch flour
* 1 cup soy flour plus 1/4 cup potato starch flour
* 1 cup corn flour
==== Commonly asked questions ====
* What is the difference between celiac disease and wheat allergy? Celiac disease and wheat allergy are two distinct conditions. Celiac disease, or "celiac sprue," is a permanent adverse reaction to gluten. Those with celiac disease will not lose their sensitivity to this substance. This disease requires a lifelong restriction of gluten. The major grains that contain gluten are wheat, rye, oats, and barley. These grains and their by-products must be strictly avoided by people with celiac disease. Wheat-allergic people have an IgE-mediated response to wheat protein. These individuals must only avoid wheat. Most wheat-allergic children outgrow the allergy.
* Are kamut and spelt safe alternatives to wheat? No. Kamut is a cereal grain which is related to wheat. Spelt is an ancient wheat that has recently been marketed as safe for wheat-allergic individuals. This claim is untrue, however. Wheat-allergic patients can react as readily to spelt as they do to common wheat.
==== Keep in mind ====
* Read labels carefully. At least one brand of hot dogs and one brand of ice cream contains wheat. It is listed on the label.
* Many country-style wreaths are decorated with wheat products.
* Some types of imitation crabmeat contain wheat.
* Wheat flour is sometimes flavored and shaped to look like beef, pork, and shrimp, especially in Asian dishes.
==See also==
Food intolerance
== Sources ==
* Wikipedia entry of food allergy
* Official website of The Food Allergy and Anaphylaxis Network
 
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