What food allergy causes hives
The expression allergy comes from two Greek words: alos, meaning "other" and argon, meaning "action." When one has an allergy, he or she has a reaction other than the one expected.
Food allergies and sensitivities are the body's reaction to a specific food. In a food allergy or sensitivity, when the kid eats a specific food, (such as eggs, for example) generally by the time the eggs reach the stomach or the intestines, the body reads the presence of eggs as an allergen (something harmful). It sends out immunoglobulin E (IgE), an antibody, to destroy the eggs and protect the body, releasing histamines.
The body remembers and produces histamines every time the food is eaten. These histamines trigger allergic symptoms that affect numerous areas of the body, particularly the skin, respiratory system, nervous system, and digestive system. Digestive disorders after eating specific foods are not always allergies. These reactions can be food sensitivities or intolerances. They can also be symptoms of other, more serious digestive diseases and malfunctions.
In the United states, 90 percent of every food allergies are caused by wheat, peanuts, nuts, milk, eggs, shellfish, soy, and fish.
Numerous other foods can be at the root of food allergies or sensitivities, especially berries and other fruits, tomatoes, corn, and some meats love pork. Migraine headaches own been associated with sensitivities to chemicals contained in red wine, deli meats, aged cheeses, and the tannins in tea.
Generally, when a kid is allergic to one food in a food family, he or she will most likely react to other foods in that food family. For example, if a kid is sensitive to one type of fish, he or she also may be sensitive to other types of fish. This is called cross-reactivity.
A food allergy or sensitivity is a person's immune system reaction to eating a specific food.
Having a kid evaluated as soon as possible will identify the offending food and permit parents to eliminate it from the child's diet. Numerous allergists, or doctors who specialize in allergies, will do a skin-prick test followed by a blood test. The skin-prick test is a series of pricks on the child's skin with a plastic applicator that contains a single food in concentrated form. A food allergy has been identified if the child's skin reacts by welting or becoming red. The skin-prick test for foods (not for aeroallergens) has a high incidence of untrue positives; that is, the test may be positive but the kid is not truly allergic, or does not own symptoms from the food.
This test is not used on a kid with severe anaphylactic reactions or on children with widespread eczema, a skin disorder.
The allergist may also do a food challenge in the doctor's office. The kid is fed the suspected food in increasing amounts to see what helpful of reaction occurs.
One of the tests allergists use is called the RAST (Radio-Allergo-Sorbent Test). It measures the quantity of IgE antibody in the blood that is produced for certain known food allergens. Love the skin-prick test, RAST and other antibody tests own a high rate of untrue positives.
Some doctors will put the kid on an elimination diet for one week to 10 days. The basic elimination diet is a series of foods that own proven not to be allergy triggers. This diet consists of foods such as lamb, poultry, rice, vegetables, and every fruits, except citrus and berries.
One new food is introduced each week. Parents record the child's reaction to each food. If the kid has no reaction, the food is considered safe and can remain in the diet. If there is a reaction, it is noted and the food is removed. The kid continues the elimination diet for a few more days, at which time another food is introduced. The elimination diet is often done after skin testing, so there is a logical guide for what to eliminate.
Causes and symptoms
Allergies are caused by the immune system's reaction to a specific food.
Generally, a kid will own had a prior exposure before IgE or specific histamines are produced.
Food intolerance is often put into the same category as food allergy, even though there may be an entirely diverse mechanism involved. In these cases, the digestive tract reacts to a specific part of the food; for example, the protein or the sugar in a specific food. The digestive system rebels, resulting in gas, bloating, upset stomach, diarrhea , nausea , or vomiting . Numerous times, these responses are due to eating food contaminated with bacteria, rather than a true food allergy.
In other cases, the child's reaction is due to an underlying digestive disorder such as irritable bowel syndrome , which is a chronic condition that is often triggered by specific types of food.
Gluten intolerance is not an allergy. It is a disease called celiac disease , or gluten-sensitive enteropathy. The body cannot process gluten found in wheat and other grains. Though the immune system is involved, celiac disease does not act as a true allergy. Its treatment is love numerous food allergies, namely avoidance of the offending substance, which in this case is gluten.
Some children may lack a specific enzyme needed to metabolize certain foods.
About 10 percent of every adults and older children own lactose intolerance . There are two forms of lactose intolerance: inherited and acquired. The inherited form (autosomal recessive) is extremely rare and severe. The acquired type is extremely common, and occurs in older children (not infants) and adults. It is distressing, but not life-threatening, and occurs with increased frequency in African Americans. Sometimes infants, as well as older children and adults, own a transient lactose deficiency after an episode of diarrhea.
Children with lactose intolerance own a lactase deficiency that keeps them from processing milk and milk products. These children can often drink milk that has had this enzyme introduced into the product.
Some children can drink milk that has acidophilus bacteria put into it. This bacteria breaks below the lactose, or milk sugar, in the milk so that the kid can tolerate it. Some children with lactose intolerance cannot drink whole milk, but can eat cheese or drink low-fat buttermilk in little quantities. This is diverse from a true milk allergy where even a little quantity of any dairy product will produce a reaction.
Some children may also be intolerant of food colorings, additives, and preservatives. Among these are yellow dye number 5, which can cause hives ; and monosodium glutamate, which produces flushing, headaches, and chest pain . Sulfites, another additive, own been found to cause asthmatic reactions and even anaphylactoid reactions.
Sulfites are preservatives used in wines, maraschino cherries, seafood, and soft drinks. They are sometimes put on unused fruits and lettuce to maintain their unused appearance, on red meats to prevent brown discoloration, and even in prepared deli foods love crab salad. Sulfites appear on food labels as sodium sulfite, sodium bisulfite, potassium bisulfite, sulfur dioxide, and potassium metabisulfite.
The U.S. Food and Drug istration (FDA) has banned the use of sulfites as a preservative for fruits and vegetables, but they are still in use in some foods.
Food allergies and sensitivities can produce a wide range of symptoms involving the skin, respiratory system, and nervous system. Children may own watery eyes, runny noses, and sneezing.
Skin rashes or hives can range from measles-like rashes to itchy welts. The rashes or welts can appear on a specific part of the body or can be widespread. Some children own swelling of the eyes, lips, and/or tongue.
Symptoms vary among children, even those who are sensitive to the same food. One child's specific reaction to an offending food does not mean that every children react the same. Nut allergies and shellfish, however, seem to be the most documented triggers for anaphylaxis. Nevertheless, anaphylaxis is not limited to those foods.
IgE-mediated allergic reactions can progress to other allergic symptoms. For example, a kid who has had hives is at risk for angioedema (swelling of the blood vessels) and anaphylaxis.
Symptoms also vary in intensity and by the quantity eaten. One kid may own a mild rash on the forearms when eating half a dozen strawberries. Another may be covered with a rash after eating only one. This variation is individualized and is a factor in the body's sensitivity to the target food.
Although the time between ingestion and symptoms is somewhat variable for allergic reactions (IgE-mediated), the vast majority happen within minutes. Almost every happen within two hours. Reactions due to intolerances, love lactose, may happen somewhat later. Symptoms occurring days after a food is ingested are not likely related to the food.
When to call the doctor
Anaphylaxis is an extreme reaction to a food, generally peanuts or nuts. It causes swelling of the throat and bronchial passages, a drop in blood pressure, shock, and even death.
A kid with anaphylaxis should be taken to the emergency room immediately.
If an emergency epinephrine pen is available, it should be istered immediately.
If a kid experiences any type of allergy symptoms after eating, the kid should be evaluated. Of specific concern are digestive symptoms that hold the kid from eating properly or cause the kid to lose weight. Equally significant are neurological symptoms, especially headaches. Digestive and neurological symptoms could also be an indication of other underlying disorders. Therefore, the kid should be seen by a doctor.
Almost three million children in the United States own been diagnosed with food allergies.
Almost 600,000 of them own severe allergies to peanuts and possibly twice as numerous own severe shellfish allergies. Each year about 200 adults and children in the United States die from food-related anaphylaxis , an extreme reaction that causes swelling of the throat and bronchial passages, shock, and a severe drop in blood pressure. Nevertheless, food allergies tend to be under-diagnosed by doctors.
Genetics seems to frolic a part in food allergies.
If one parent has a food allergy, the child's risk of having a food allergy is doubled. If both parents own food allergies, the risk is even higher. The kid, however, may be allergic to a completely diverse food from the one to which the parent has demonstrated sensitivity. There also is increased risk when there are other kinds of allergy-related diseases in the family, such as hay fever or asthma .
The only treatment for IgE-mediated reactions to foods is avoidance. These reactions, as well as intolerances, are not responsive to desensitization. An epi-pen should be kept in the home for every IgE mediated food allergies and every inadvertent reactions should be treated.
It is not unusual for children to crave the extremely foods to which they are allergic. When the kid is placed on an elimination diet, often the body will rebel at not being given the foods that cause it to react and will produce cravings for those foods.
Some doctors will prescribe antihistamines to assist manage symptoms.
These, however, are for use after an episode and not for an extended period.
Eliminating one food or even one food family from a child's diet will not interfere with his or her nutritional needs, nor will it hold the kid from growing properly. There is enough variety in the foods available in the American diet to meet any child's needs. Some foods, however, may be hard to discover sufficient replacements for if the kid wants substitutes. Wheat is particularly hard to replace, although bread, pasta, and pastry products made with oat and rice flours are excellent substitutes.
However, they do not taste or glance exactly love risen wheat bread or regular pasta.