Food allergies or food intolerances, affect nearly everyone at some point. People often have an unpleasant reaction to something they ate and wonder if they have a food allergy.
One out of three people either say that they have a food allergy or that they modify the family diet because a family member is suspected of having a food allergy. This difference between the clinically proven prevalence of food allergy and the public perception of the problem is in part due to reactions called "food intolerances" rather than food allergies. A food allergyor hypersensitivity, is an abnormal response to a food that is triggered by the immune system.
The immune system is not responsible for the symptoms of a food intolerance, even though these symptoms can resemble those of a food allergy. For example, food allergies and adenose, being allergic to milk is different from not being able to digest it properly due to lactose intolerance.
It is extremely important for people who have true food allergies to identify them and prevent allergic reactions to food, because these reactions can cause devastating illness and, in some cases, food allergies and adenose, death. Food allergies involve two features of the human immune response. One is the production of immunoglobulin E IgEa type of protein called an antibody that circulates through the blood.
The other is the mast cell, a specific cell that occurs in all body tissues but is especially common in areas of the body that are typical sites of allergic reactions, including the nose and throat, lungsskinand gastrointestinal tract. The ability of a given individual to form IgE against something as benign as food is an inherited predisposition. Generally, such people come from families in which allergies food allergies and adenose common -- not necessarily food allergies but perhaps hay feverasthmaor hives.
Someone with two allergic parents is more likely to develop food allergies than someone with one allergic parent. Before an allergic reaction can occur, a person who is predisposed to form IgE to foods first has to be exposed to the food.
As this neem and diabetes is digested, it triggers certain cells to produce specific IgE in large amounts. The IgE is then released and attaches to the surface of mast cells. The next time the person eats that food, it interacts with specific IgE on the surface of the mast cells and triggers the cells to release chemicals such food allergies and adenose histamine.
Depending upon the tissue in which they are released, these chemicals will cause a person to have various food allergy symptoms. If the mast cells release chemicals in the ears, nose, and throat, a person may feel an itching in the mouth and may have trouble food allergies and adenose or swallowing, food allergies and adenose.
If the affected mast cells are in the gastrointestinal tract, the person may have abdominal painvomitingor diarrhea. The chemicals released by skin mast cells, in contrast, can prompt hives. Food allergens the food fragments responsible for ginko bilboa leaf extract and diabetes allergic reaction are proteins within the food that usually are not broken down by the heat of cooking or by stomach acids or enzymes that digest food.
As a result, they survive to cross the gastrointestinal lining, enter the bloodstream, and go to target organs, causing allergic reactions throughout the body. The complex process of digestion affects the timing and the location of an allergic reaction. If people are allergic to a particular food, for example, they may first experience itching in the mouth as they start to eat the food.
After the food is digested in the stomachabdominal symptoms such as vomitingdiarrhea, or pain may start. When the food allergens enter and travel through the bloodstream, they can cause a drop in blood pressure. As the allergens reach the skin, they can induce hives or eczemaor when they reach the lungsthey may cause bronchospasm wheezing or constriction of the lungs. All of this takes place within a few minutes to an hour. In children, the food allergy pattern is somewhat different.
The most common food allergens that cause problems in children are eggs, milk, and peanuts. Adults usually do not lose their allergies, food allergies and adenose, food allergies and adenose children can sometimes outgrow them. Children are more likely to outgrow allergies to milk, eggs, or soy than allergies to peanuts, fish, or shrimp. The foods that adults or children react to are those foods they eat often.
In Japan, for example, rice allergy is more frequent. In Scandinavia, codfish allergy is more common. If someone has a life-threatening allergic reaction to a certain food, the doctor will counsel the patient to avoid similar foods that might trigger this reaction.
For example, if someone has a history of allergy to shrimp, testing will usually show that the person is not only allergic to shrimp but also to other shellfish like crab, lobster, and crayfish.
This is called cross-reactivity. Another interesting example of cross-reactivity occurs in people who are highly sensitive to ragweed. During ragweed pollination season, these people sometimes find that when they try to eat melons, particularly cantaloupe, they have itching in their mouth and they simply cannot eat the melon.
Similarly, people who have severe birch pollen allergy also may react to the peel of apples. This is called the "oral allergy syndrome. A differential diagnosis means distinguishing a food allergy from food intolerance or other illnesses. One possibility is the contamination of foods with microorganisms, such as bacteria, and their products, such as toxins. Contaminated meat sometimes mimics a food allergy when it is really a food allergies and adenose of food poisoning.
There are also natural substances, such food allergies and adenose histamine, that can occur in foods and stimulate a reaction similar to an allergic reaction. For example, food allergies and adenose, histamine can reach high levels in cheese, some wines, and in certain kinds of fish, particularly tuna and mackerel. If someone eats one of these foods with a high level of histamine, that person may have a reaction that strongly resembles an allergic reaction to food.
This reaction is called histamine toxicity, food allergies and adenose. Another cause of food intolerance that is often confused with a food allergy is lactase deficiency, food allergies and adenose, also known as lactose intolerance. This most common food intolerance affects at least one out of ten people.
Lactase is an enzyme that is in the lining of the gut. This enzyme degrades lactose, food allergies and adenose, which nail problems and cancer in milk and other dairy products. If a person does not have enough lactase, the body cannot digest the lactose in most dairy products. Instead, the lactose is used by bacteria, gas is formed, and the person experiences bloatingabdominal pain, and sometimes diarrhea.
Another type of food intolerance is an adverse reaction to certain products that are added to food to enhance taste, provide color, or protect against the growth of microorganisms.
Compounds that are food allergies and adenose frequently tied to adverse reactions that can be confused with food allergy are yellow dye number 5, monosodium glutamate, and sulfites. Yellow dye number 5 can cause hives, although rarely.
Monosodium glutamate MSG is a flavor enhancer, and, when consumed in large amounts, can cause flushing, sensations of warmth, headachefacial pressure, chest painor feelings of detachment in some people. These transient reactions occur rapidly after eating large amounts of food to which MSG has been added.
Sulfites can occur naturally in foods or are added to enhance crispness or prevent mold growth. Sulfites in high concentrations sometimes pose problems for people with severe asthma. Sulfites can give off a gas called sulfur dioxide, which the asthmatic inhales while eating the sulfited food. This irritates the lungs and can send an asthmatic into severe bronchospasm, a constriction of the lungs.
Such reactions led the FDA to ban sulfites as spray-on preservatives in fresh fruits and vegetables, food allergies and adenose. But they are still used in some foods and are made naturally during the fermentation of wine, for example. There are several other diseases that share symptoms with food allergies, food allergies and adenose, including ulcers and cancers of the gastrointestinal tract.
These disorders can be associated with food allergies and adenose, diarrhea, or cramping abdominal pain exacerbated by eating, food allergies and adenose. Gluten intolerance is associated with the disease called gluten-sensitive enteropathy or celiac disease. It is caused by an abnormal immune response to gluten, which is a component of wheat and some other grains.
Some people may have a food intolerance that has a psychological trigger. The eating of that food years later, even as an adult, is associated with a rush of unpleasant sensations that can resemble food allergies and adenose allergic reaction to food. To diagnose a food allergy a doctor must first determine if the patient is having an adverse reaction to specific foods.
The first of these techniques is the most valuable. The doctor sits down with the person suspected of having a food allergy and takes a history to determine if the facts are consistent with a food allergy.
The doctor asks such questions as:. Sometimes a food allergy diagnosis cannot be made solely on the basis of history. In that case, the doctor may ask the patient to go back and keep a record of the contents of each meal and whether he or she had a reaction. This gives more detail from which the doctor and the patient can determine if there is consistency in the reactions. The next step some doctors use is an elimination diet.
If the patient removes the food and the symptoms go away, the doctor can almost always make a diagnosis. This technique cannot be used, however, if the reactions are severe in which case the patient should not resume eating the food or infrequent.
Also thought to be helpful in diagnosing food allergies is an oral food challenge. This is done under strict medical supervision. One of food allergies and adenose is a scratch puncture test, during which a dilute extract of the food is placed on the skin of the forearm or back.
A skin food allergies and adenose is made through the droplet with a needle and observed for swelling or redness that would indicate a local allergic reaction. Skin tests are rapid, simple, and loud music and blood pressure safe although experts link shark cartilage and cancer not recommend making a food allergy diagnosis based on a skin test alone.
A patient can have a positive skin test to a food allergen without experiencing allergic reactions to that food. A doctor diagnoses a food allergy only when a patient has a positive skin test to a specific allergen and the history of these reactions suggests an allergy to the same food. In some extremely allergic patients who have severe anaphylactic reactions, skin testing cannot be used because it could evoke a dangerous reaction.
Skin testing also cannot be done on patients with extensive eczema. These tests measure the presence of food-specific IgE in the blood of patients. These tests may cost more than skin tests, and results are not available immediately. As with skin testing, positive tests do not necessarily make the diagnosis. The final method used to objectively diagnose food allergy is a double-blind food challenge.
This testing has come to be the "gold standard" of allergy testing. Various foods, some of which are suspected of inducing an allergic reaction, are each placed in individual opaque capsules.