Food Allergy Survival Guide

Food Allergies

Food Allergies

Peanuts can leave you breathless. Cat dander can lead to itchy eyes, a stuffy nose, coughing and sneezing. And most of us have suffered through those seasonal allergies with horrible pollen counts. Learn more...

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Food Allergy Or Food Intolerance

Between 12 and 20 of Americans, British and Dutch people complain about food allergies. In fact, problems are more likely to be due to food intolerance rather than actual allergy. This has been confirmed by skin-prick tests, analysis of immunoglobulin E level in serum, and enzyme-linked immunosorbent assay (ELISA) tests which found food intolerance in 2 to 5 of adults and 6 to 13 of children (age 1 to 6) in Europe. Challenge-proved adverse reaction to food is one tenth of that perceived and allergic reactions to chemicals and additives in food are even more rare. A similar ratio occurs in Asia. The dietary habits in different countries determine the observed rates of food sensitivities. Sensitivity to fish occurs frequently in Scandinavia, to rice in Japan, to peanuts in the U.S. and the U.K., and to seafood and milk in Italy. It also means that communities not exposed to particular allergens are not affected as frequently by various forms of sensitivities, e.g., allergy to peanuts is...

Patomechanism Of Food Allergy

According to Gell and Coombs classification, allergy Type III occurs when large numbers of antibody-antigen complexes accumulate in tissues. Complexes consist of IgM or IgG (IgG1 or IgG3) and an allergen. In the case of food allergy, antibody excess and mild antigen excess lead to the creation of complexes. They are localized to the site of introduction, activate complement, and trigger a process of infiltration with polymorphonuclear leucocytes. It results in acute inflammatory response and damage to cells with complexes attached. It is a probable mechanism of colitis ulcerosa, where high concentrations of antibodies against casein, lactoalbumin, and lactoglobulin are detected (Halstensen et al., 1990).

Food Allergy Symptoms

Food allergy is a syndrome that affects 3 to 6 of the population in various countries. In early childhood it occurs as a result of contact with new food components and excessive permeability of GI mucous membranes. As the immunological systems develops, in most cases symptoms recede or food tolerance occurs - usually at the age of three. Studies carried out on a population of Japanese children revealed that the earliest remission occurs in case of allergy to soy, followed by allergy to egg yolk, egg white, wheat, and cows' milk (usually between the ages of two and three) (Ebisawa et al., 2003). Despite medical progress, the diagnosis of food allergy remains difficult because the allergic symptoms are caused by a variety of different types of allergens, to which people may be simultaneously or successively exposed. Food allergy affects more and more people in the world, with many reported cases of deaths caused by anaphylaxis. To prevent such situations, many countries have changed...

Food Allergy vs Food Intolerance

Food allergy and food intolerance are not the same thing. A food intolerance is an adverse food-induced reaction that does not involve the immune system (such as lactose intolerance). A child with lactose intolerance lacks an enzyme that is needed to digest milk sugar, and will suffer from gas, bloating, and abdominal pain after ingesting milk. A 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 cause hives, asthma, or other symptoms of an allergic reaction.

Food Allergies Milk and Wheat

Although food allergies that trigger sinusitis are relatively rare, they do occur often enough that I'm always on the lookout for them in people whose symptoms cannot be explained by more common causes. The tip-off that such an allergy may be present is when postnasal drip is the primary symptom. If you are particularly bothered by such drainage or constant collection of phlegm in the back of the throat, especially upon awakening you may well have a food allergy and not even be aware of it. What causes food allergies is not well understood, but it's clear that when certain people eat specific foods, undesirable reactions occur. In some cases, such as allergies to shellfish or peanuts, these effects can be immediate, resulting in hives or swelling of the face or throat. In severe cases, these allergic reactions can be life-threatening. Diagnosing food allergies can be a bit tricky, as there is no standardized approach used by all allergists and test results can be unreliable. Some...

Food Allergies

Food allergies may cause only an itchy mouth and throat other allergies trigger a rash or cramping, with nausea and vomiting or diarrhea, as the body attempts to flush out the irritant. still other common allergic food symptoms include hives, and in more severe cases, shortness of breath. In severe reactions (such as in tree nut or peanut allergies), the child may develop a sudden, life-threatening reaction called anaphylactic shock. severity of food allergies and when they develop depends on the quantity of the food eaten, the amount of exposure the child has had, and the child's sensitivity to the food. Common foods that may cause allergies include cow's milk, soy, egg, wheat, seafood, nuts, and peanuts. severe symptoms or reactions to any allergen require immediate medical attention. Children with a severe allergy to foods must carry injectable epinephrine (Epipen), which can reverse anaphylactic shock. Fortunately, severe or life-threatening allergies occur only in a small group...

Lactose intolerance

The lactose tolerance test begins with the child fasting before the test and then drinking a liquid that contains lactose. Several blood samples are taken over a two-hour period to measure the child's blood sugar level, which indicates how well the body is able to digest lactose. Normally, when lactose reaches the digestive system, the lactase enzyme breaks down lactose into glucose and galactose. The liver then changes the galactose into glucose, which enters the bloodstream and raises the person's blood glucose level. If lactose is incompletely broken down, the blood glucose level does not rise and a diagnosis of lactose intolerance is confirmed. The lactose tolerance and hydrogen breath tests are not given to infants and very young children who are suspected of having lactose intolerance. A large lactose load may be dangerous for very young individuals because they are more prone to dehydration that can result from diarrhea caused by the lactose. If a baby or young child is...

Influence Of Environmental Factors

During the era of an increase in GI allergy diseases, probiotics seem to play a more significant role (Kirjavainen et al., 1999) in preventing against allergies by their immunoregulatory effects on immunity (TLR ligands) and Th1 lymphocyte stimulation (Lignau et al.,1995). The occurrence of food allergy among children is linked to

Induction And Gene Regulation

In Chapter 14, when we talked about absent essentials and monkey wrenches, we talked about the various ways in which messing up a protein can cause a problem. When we discussed some of the common types of mutations, we focused on the coding sequence and mutations that change the resulting protein product. In the case of hypolactasia (a state of reduced lactase activity resulting in lactose intolerance) it looks as if we might be dealing with a different type of mutation, a mutation in the promoter region that affects regulation of expression of the gene. So what is causing Ari's lactose intolerance Theories have evolved over the years regarding the cause of lactose intolerance, but it was not until 2002 that a possible cause was identified. A group of researchers in Finland, where about 18 of the population is lactose intolerant, studied the gene responsible for making the lactase enzyme. The exons of the gene that makes the lactase enzyme (called lactase-phlorizin hydrolase) are...

So What Or Who Is Normal Anyway

So what is the normal genotype, or for that matter, what is the normal phenotype There is a tendency to think that the genotype that makes you sick must be the mutant genotype, and that the phenotype that involves illness must be the mutant phenotype. Certainly, the way lactose intolerance and lactase persistence are talked about further contributes to this idea. People who get sick when they drink milk are said to have lactose intolerance it is something they go to the doctor about, perhaps even something they use medication for (the enzyme tablets to digest the lactose). You will notice that, earlier, we asked what is causing Ari's lactose intolerance, and it seemed like a perfectly normal question. We would bet that you did not find yourself saying, No, that's the wrong question. The question is why there are people who don't get sick when they drink milk In fact, the right question really is, What makes some people persist in making high levels of lactase long after being weaned...

La Crosse encephalitis See encephalitis la crosse

Lactose intolerance The inability to digest milk sugar (lactose) because of a lack of the digestive enzyme lactase normally produced in the cells lining the small intestine. Lactase breaks down milk sugar into simpler forms that can then be absorbed into the bloodstream. When there is not enough lactase to digest the amount of lactose consumed, the results are gas, bloating, and abdominal pain. It is more common in African Americans than Caucasians. While not all children deficient in lactase have symptoms, those who do are considered to be lactose intolerant. Even though lactose intolerance is widespread, it need not pose a serious threat to good health. Children who have trouble digesting lactose can learn which dairy products and other foods they can eat without discomfort and which ones they should avoid. Many will be able to enjoy milk, ice cream, and other such products if eaten in small amounts or eaten with other food. Lactase liquid or tablets may also help digest the lactose.

Box 243 Pharmacogenetics

Trait will only be manifested by people who have been exposed to the food or allergen. A trait called favism is characterized by a form of hemolytic anemia that happens after consumption of fava beans. Someone who has never consumed fava beans would not know whether they would be susceptible to favism or not. The genetics of lactase persistence lactose intolerance, discussed in Chapter 17, is very hard to evaluate in countries where dairy products are not part of the diet. Sorting out the genetic components of allergies can be especially difficult because often people with allergies react to many different allergens, not just one, while being exposed to a vastly larger array of potential allergenic culprits. However, in some cases, such as penicillin allergy, the eliciting event (taking the antibiotic) and the unusual nature of the allergic reaction (a rash) make it easier to identify than some more generalized allergies to airborne allergens.

Flattened head syndrome See positional plagio

Food allergy 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 in an attempt to protect the body. The next time the child eats that food, the immune system releases massive amounts of chemicals (including hista-mine) in order to protect the body. These chemicals trigger a cascade of allergic symptoms that can affect breathing, the heart, the skin, or the gastrointestinal tract. Most food allergies trigger reactions such as itching, hives, and swelling, but in some cases a more serious response known as ana-phylactic shock can occur. This leads to a loss of consciousness or even death. scientists estimate that between six and seven million Americans suffer from true food allergies. Many food allergies disappear as the child gets older about a third of cases disappear in one to two years if the child carefully avoids the offending item. However,...

Nonallergic Hypersensitivity Reaction

Non-allergic hypersensitivity reaction corresponds with the traditional term 'food intolerance'. It affects about 20 of patients, inducing symptoms similar to those observed during an allergy bout, however, it is triggered by non-immunological mechanisms. Some medicines, such as non-steroid anti-inflammatory drugs, convertase inhibitors, and p-blockers, may intensify food allergy symptoms (Brooks et al., 1989 Meune et al., 2000 Tenenbaum et al., 2000).

The Problem With Diagnosing An Inducible Phenotype

In the case of Ari's family, what we see looks a lot like recessive inheritance of a disease gene (Figure 17.2), but it can sometimes be hard to tell if someone has lactose intolerance if they are not exposed to a lot of lactose. Her father's family, with western European ancestry and a standard American diet full of dairy products, appears to be full of lactose-persistent people. However, it is actually harder to tell about people on her mother's side of the family, who consume a more standard Middle Eastern diet. Although they also use dairy products, they eat recipes based on yogurt more often than milk, and drink tea or wine or water more often than milk. Lactose intolerance can be hard to diagnose even in someone who is exposed to a lot of milk, as happened with Ari someone who is consuming a nearly lactose-free diet simply because of cultural context may not even know whether milk gives them problems. We know from many studies of other families and individuals that lactase...

Differential Diagnosis

The differential diagnosis in this infant at the time of her second ED visit included an IEM, sepsis, severe dehydration, and liver dysfunction, with IEM at the top of the list. Many IEM cases classically present a few days after birth with increasing lethargy and decreasing food intake or food intolerance. In utero these infants are well because of the normal functioning of the maternal enzymes to perform the reactions that are deficient in the fetus. Depending on the specific IEM in question, pregnancies are often uncomplicated, and weight and health status of the infant at birth are normal. After birth, the infant's own enzymes are required for metabolizing ingested nutrients, and complications ensue where a metabolic block exists. Classically these infants present with a variety of general symptoms that may include lethargy, hypotonia, hypo-glycemia, acidemia, elevated liver enzymes, and hyperammonemia. Although not noted in this case, in some cases the urine may have an odor. For...

Thymic humoral factor gamma 2 THF g2 A

Thymomodulin A thymic peptide, a natural extract of calf thymus. In Italy, where it has been approved (under the trade name Leucotrofina), it is used to treat bacterial and viral infections, food allergies in children, and immunodeficiencies in the elderly. unlike most synthetic peptides, thymo-modulin is an oral drug. It is made into syrup from the filtered freeze-dried calf thymus extract.

Mushrooms Causing Gastrointestinal Disorders

Paxillus syndrome is a food allergy, not a true poisoning. As a consequence, some who eat the mushrooms will not develop symptoms. Symptoms may include colic, vomiting, diarrhea, oliguria or anuria, kidney pain, hemoglobi-nuria, and renal failure. A hemagglutination test has been used for confirmation (Bresinsky and Besl, 1990).


Parents often are able to diagnose hay fever. While a common cold or upper respiratory infection can be confused with allergic rhinitis, parents should suspect rhinitis if the child has irritated eyes and no fever. Food allergies can also cause rhinitis symptoms in 70 percent of infants and young children, but with food allergies there are often other symptoms of skin or stomach irritation as well. A careful history usually reveals the seasonal nature of the complaint and the suspected role of seasonal allergens. Physical examination usually reveals puffy, reddened watery eyes, a red throat, and nostrils filled with clear watery mucus.

What Is An Allergy

The European Academy of Allergology and Clinical Immunology (EAACI) defines a food allergy in the following way (Johansson, 2002) We propose that an adverse reaction to food should be called food hypersensitivity. When immunologic mechanisms have been demonstrated, the appropriate term is food allergy, and, if the role of IgE Immunoglobulin E is highlighted, the term is IgE-mediated food allergy. All other reactions, previously sometimes referred to as ''food intolerance,'' should be referred to as nonallergic food hypersensitivity. Severe, generalized allergic reactions to food can be classified as anaphylaxis.

Animal Allergens

An allergist can determine the cause of an allergy by using skin tests for the most common environmental and food allergens. In the test, a drop of a purified liquid form of the allergen is placed on the skin, or injected just under the skin. After about 15 minutes, if a reddened swelling appears at the injection site, the test is positive. Skin tests are less expensive and more accurate than blood tests for allergies, but blood tests may be required in children with skin conditions or those who are extremely sensitive to a particular allergen. Blood tests can also help determine if a child has outgrown a food allergy.


The food colour tartrazine is a well-known food additive which is currently still in use, although it was removed from many products as a result of consumer pressure. Known also as E102 in Europe and FD&C yellow no. 5 in the USA, tartrazine is an azo dye with an intense yellow orange colour. Its similarity in colour to natural orange juice has meant that it is used extensively in the soft drink industry, and it has been also used in products as wide-ranging as breadcrumbs and medicines. It is one of the colours most frequently implicated in food intolerance studies and also in reactions to pharmaceutical preparations to which it was sometimes added. Effects occur most commonly in children, and it is thought that i in i0,000 children are sensitive to tartrazine. According to Feingold and his team, adverse reactions to tartrazine seem to occur most commonly in subjects who are also sensitive to aspirin and salicylic acid, a finding that has been confirmed by other studies.4 Depending on...