Food allergy Health Dictionary

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Food Allergy: From 1 Different Sources

An inappropriate or exaggerated reaction of the immune system to a food. Sensitivity to cow’s milk protein is a fairly common food allergy in young children. Other foods most commonly implicated in food allergy are nuts, wheat, fish, shellfish, and eggs. Food allergy is more common in people who suffer from other forms of allergy or hypersensitivity, such as asthma, allergic rhinitis, and eczema.Immediate reactions, occurring within an hour or sometimes minutes of eating the trigger food, include lip swelling, tingling in the mouth or throat, vomiting, abdominal distension, abnormally loud bowel sounds, and diarrhoea. Some serious allergies can cause anaphylactic shock, requiring immediate self-injection with adrenaline (epinephrine). The only effective treatment for food allergy is avoidance of the offending food. (See also food intolerance.)
Health Source: BMA Medical Dictionary
Author: The British Medical Association

Allergy

A term generally used to describe an adverse reaction by the body to any substance ingested by the affected individual. Strictly, allergy refers to any reactions incited by an abnormal immunological response to an ALLERGEN, and susceptibility has a strong genetic component. Most allergic disorders are linked to ATOPY, the predisposition to generate the allergic antibody immunoglobulin E (IgE) to common environmental agents (see ANTIBODIES; IMMUNOGLOBULINS). Because IgE is able to sensitise MAST CELLS (which play a part in in?ammatory and allergic reactions) anywhere in the body, atopic individuals often have disease in more than one organ. Since the allergic disorder HAY FEVER was ?rst described in 1819, allergy has moved from being a rare condition to one a?icting almost one in two people in the developed world, with substances such as grass and tree pollen, house-dust mite, bee and wasp venom, egg and milk proteins, peanuts, antibiotics, and other airborne environmental pollutants among the triggering factors. Increasing prevalence of allergic reactions has been noticeable during the past two decades, especially in young people with western lifestyles.

A severe or life-threatening reaction is often termed ANAPHYLAXIS. Many immune mechanisms also contribute to allergic disorders; however, adverse reactions to drugs, diagnostic materials and other substances often do not involve recognised immunological mechanisms and the term ‘hypersensitivity’ is preferable. (See also IMMUNITY.)

Adverse reactions may manifest themselves as URTICARIA, wheezing or di?culty in breathing owing to spasm of the BRONCHIOLES, swollen joints, nausea, vomiting and headaches. Severe allergic reactions may cause a person to go into SHOCK. Although symptoms of an allergic reaction can usually be controlled, treatment of the underlying conditon is more problematic: hence, the best current approach is for susceptible individuals to ?nd out what it is they are allergic to and avoid those agents. For some people, such as those sensitive to insect venom, IMMUNOTHERAPY or desensitisation is often e?ective. If avoidance measures are unsuccessful and desensitisation ine?ective, the in?ammatory reactions can be controlled with CORTICOSTEROIDS, while the troublesome symptoms can be treated with ANTIHISTAMINE DRUGS and SYMPATHOMIMETICS. All three types of drugs may be needed to treat severe allergic reactions.

One interesting hypothesis is that reduced exposure to infective agents, such as bacteria, in infancy may provoke the development of allergy in later life.

Predicted developments in tackling allergic disorders, according to Professor Stephen Holgate writing in the British Medical Journal (22 January 2000) include:

Identi?cation of the principal environmental factors underlying the increase in incidence, to enable preventive measures to be planned.

Safe and e?ective immunotherapy to prevent and reverse allergic disease.

Treatments that target the protein reactions activated by antigens.

Identi?cation of how IgE is produced in the body, and thus of possible ways to inhibit this process.

Identi?cation of genes affecting people’s susceptibility to allergic disease.... allergy

Food Poisoning

This illness is characterised by vomiting, diarrhoea and abdominal pain, and results from eating food contaminated with metallic or chemical poisons, certain micro-organisms or microbial products. Alternatively, the foods – such as undercooked red kidney beans or ?sh of the scombroid family (mackerel and tuna) – may contain natural posions. Food poisoning caused by chemical or metallic substances usually occurs rapidly, within minutes or a few hours of eating. Among micro-organisms, bacteria are the leading cause of food poisoning, particularly Staphylococcus aureus, Clostridium perfringens (formerly Cl. welchii), Salmonella spp., Campylobacter jejuni, and Escherichia coli O157.

Staphylococcal food poisoning occurs after food such as meat products, cold meats, milk, custard and egg products becomes contaminated before or after cooking, usually through incorrect handling by humans who carry S. aureus. The bacteria produce an ENTEROTOXIN which causes the symptoms of food poisoning 1–8 hours after ingestion. The toxin can withstand heat; thus, subsequent cooking of contaminated food will not prevent illness.

Heat-resistant strains of Cl. perfringens cause food poisoning associated with meat dishes, soups or gravy when dishes cooked in bulk are left unrefrigerated for long periods before consumption. The bacteria are anaerobes (see ANAEROBE) and form spores; the anaerobic conditions in these cooked foods allow the germinated spores to multiply rapidly during cooling, resulting in heavy contamination. Once ingested the bacteria produce enterotoxin in the intestine, causing symptoms within 8–24 hours.

Many di?erent types of Salmonella (about 2,000) cause food poisoning or ENTERITIS, from eight hours to three days after ingestion of food in which they have multiplied. S. brendeny, S. enteritidis, S. heidelberg, S. newport and S. thompson are among those commonly causing enteritis. Salmonella infections are common in domesticated animals such as cows, pigs and poultry whose meat and milk may be infected, although the animals may show no symptoms. Duck eggs may harbour Salmonella (usually S. typhimurium), arising from surface contamination with the bird’s faeces, and foods containing uncooked or lightly cooked hen’s eggs, such as mayonnaise, have been associated with enteritis. The incidence of human S. enteritidis infection has been increasing, by more than 15-fold in England and Wales annually, from around 1,100 a year in the early 1980s to more than 32,000 at the end of the 1990s, but has since fallen to about 10,000. A serious source of infection seems to be poultry meat and hen’s eggs.

Although Salmonella are mostly killed by heating at 60 °C for 15 minutes, contaminated food requires considerably longer cooking and, if frozen, must be completely thawed beforehand, to allow even cooking at a su?cient temperature.

Enteritis caused by Campylobacter jejuni is usually self-limiting, lasting 1–3 days. Since reporting of the disease began in 1977, in England and Wales its incidence has increased from around 1,400 cases initially to nearly 13,000 in 1982 and to over 42,000 in 2004. Outbreaks have been associated with unpasteurised milk: the main source seems to be infected poultry.

ESCHERICHIA COLI O157 was ?rst identi?ed as a cause of food poisoning in the early 1980s, but its incidence has increased sharply since, with more than 1,000 cases annually in the United Kingdom in the late 1990s. The illness can be severe, with bloody diarrhoea and life-threatening renal complications. The reservoir for this pathogen is thought to be cattle, and transmission results from consumption of raw or undercooked meat products and raw dairy products. Cross-infection of cooked meat by raw meat is a common cause of outbreaks of Escherichia coli O157 food poisoning. Water and other foods can be contaminated by manure from cattle, and person-to-person spread can occur, especially in children.

Food poisoning associated with fried or boiled rice is caused by Bacillus cereus, whose heat-resistant spores survive cooking. An enterotoxin is responsible for the symptoms, which occur 2–8 hours after ingestion and resolve after 8–24 hours.

Viruses are emerging as an increasing cause of some outbreaks of food poisoning from shell?sh (cockles, mussels and oysters).

The incidence of food poisoning in the UK rose from under 60,000 cases in 1991 to nearly 79,000 in 2004. Public health measures to control this rise include agricultural aspects of food production, implementing standards of hygiene in abattoirs, and regulating the environment and process of industrial food production, handling, transportation and storage.... food poisoning

Food Intolerance

This is divided into food aversion, where a person simply avoids a food they dislike; food intolerance, where taking the food causes symptoms; and food allergy, where the symptoms are due to an immunological reaction. Some cases of food intolerance are due to idiosyncrasy – that is, a genetic defect in the patient, such as alactasia, where the intestine lacks the enzyme that digests milk sugar, with the result that individuals so affected develop diarrhoea when they drink milk. Intolerance to speci?c foods, as distinct from allergy, is probably quite common and may be an important factor in the aetiology of the IRRITABLE BOWEL SYNDROME (IBS).

For the diagnosis of true food allergy, it is necessary to demonstrate that there is a reproducible intolerance to a speci?c food; also, that there is evidence of an abnormal immunological reaction to it. Occasionally the allergic response may not be to the food itself but to food contaminants such as penicillin, or to food additives such as tartrazine. There may also be reactions to foods which have pharmacological effects, such as ca?eine in strong co?ee or histamine in fermented cheese, or such reactions may be due to the irritant e?ect on the intestinal mucosa (especially if it is already diseased) by, say, highly spiced curries.

Testing blood and skin for food allergy is beloved of some alternative practitioners but, in practice, the results of tests do not necessarily agree with what happens when the food is taken. Therefore, a careful history is as useful as any test in making a diagnosis.... food intolerance

Brahmi Tea Or Food For The Brain

Brahmi Tea isbest known in Indian Ayurvedic medicine for its role against motor and nerve disorders. It possesses a pungent and bitter flavor, being a tonic, a mild sedative and a diuretic. Brahmi Tea description Brahmi is a perennial creeping herb, commonly found in India, Nepal, Sri Lanka, China, Vietnam and in the southern parts of the United States. It grows on wetlands and muddy shores. Brahmi is medicinally and culinary used. It is known as “food for the brain”, brahmi being used since the 6th century in Ayurvedic medicine as a cognitive enhancer. In India, the herb is still used by students and schoolchildren to help their brain functions. Brahmi tea is the resulting beverage from brewing the abovementioned plant. Brahmi Tea brewing Brahmi tea can be made by immersing ½ teaspoon of dried brahmi herbs into one cup of boiling water. Let it soak and steep it for about 5 minutes. Drink it slowly. Brahmi Tea benefits Brahmi tea has proven its efficiency in:
  • improving the memory and enhancing mental functions, agility and alertness (It is helpful in retention of new information)
  • calming the mind and promoting relaxation
  • improving motor learning ability
  • promoting greater concentration and focus
  • treating asthma
  • treating epilepsy
  • treating indigestion
Brahmi Tea side effects High doses of Brahmi tea may causeheadaches, nausea, dizziness and extreme drowsiness. Pregnant and nursing women should not intake this beverage. Brahmi tea is a medicinal beverage successfully used to enhance the memory processes and to promote relaxation. It is also efficient in dealing with indigestion, but not only.... brahmi tea or food for the brain

Food

Mixture of substances containing CARBOHYDRATE, FAT, PROTEIN, VITAMINS, TRACE ELEMENTS and water consumed by animals, including humans, to provide the necessary nutrients to maintain the body’s METABOLISM.... food

Food Standards Agency

An independent agency recently set up by the UK government. The aim is for the agency to protect consumers’ interests in every aspect of food safety and nutrition. The agency advises ministers and the food industry, conducts research and surveillance, and monitors enforcement of food safety and hygiene laws.... food standards agency

Cow’s Milk Allergy (cma)

An estimated 8 per cent of infants suffer from cow’s milk intolerance.

Symptoms. Irritable bowel, respiratory troubles (asthma), skin disorders (eczema) and behavioural problems. Symptoms disappear when dairy products are discontinued but re-appear when they re-enter the diet.

Treatment and prevention. Garlic, for reduction of symptoms. A switch from cow’s to goat’s milk proves effective. Cases are on record of goat’s milk checking irritable bowel and the spread of eczema. ... cow’s milk allergy (cma)

Institute Of Health Food Retailing

Professional body to ensure status of those whose career is in the health food industry. Encourages training, research and education in health food retailing, health and nutrition, and furthers these objects with meetings and seminars. Holders of the NAHS Diploma of Health Food Retailing may apply for membership. On acceptance they are awarded a certificate with authority to use the designatory letters M Inst HFR.

Address: Byron House, College Street, Nottingham NG1 5AQ. ... institute of health food retailing

Desensitization, Allergy

See hyposensitization.... desensitization, allergy

Food Fad

A like or dislike of a particular food or foods that is taken to extremes. A food fad may lead to undue reliance on, or avoidance of, a particular foodstuff. Fads are common in toddlers, adolescents, and in people who are under stress. When a food fad becomes obsessive or persistent, it may indicate a serious eating disorder. (See also anorexia nervosa; bulimia.)... food fad

Health Food

A term applied to any food products thought to promote health.... health food

Food Additives

Any substance added to food for the purposes of preservation or to improve its acceptability in terms of taste, colour, or consistency.

Preservatives, such as sodium nitrate, are added to food to control the growth of bacteria, moulds, and yeasts. Other additives, such as antioxidants, improve the keeping quality of food by preventing undesirable changes (they stop rancidity in foods containing fat, for example). Additives that improve texture include emulsifiers, stabilizers, thickeners, and gelling agents. Appearance and taste are improved by the use of colourings, flavourings, sweeteners, and flavour enhancers. Artificial sweeteners, such as saccharin, may be used instead of sugar, especially in products for diabetics or slimmers.

Certain additives may produce an allergic reaction in some people, and some are thought to be a factor in behavioural problems in children.... food additives

Food-borne Infection

Any infectious illness caused by eating food contaminated with viruses, bacteria, worms, or other organisms. There are 2 mechanisms by which food can become infected. First, many animals that are kept or caught for food may harbour disease organisms in their tissues or organs; and, if meat or milk from such an animal is eaten without being thoroughly cooked or pasteurized, the organisms may cause illness in their human host. In the , the only common infection of this type is food poisoning. Second, food may be contaminated with organisms spread from an infected person or animal, usually by flies moving from faeces to food.

Immunization is available against certain food- and water-borne infections such as typhoid fever.... food-borne infection

Irradiation Of Food

The treatment of food with ionizing radiation to kill bacteria, moulds, insects, and other parasites. It improves the keeping qualities of food and is a means of controlling some types of food poisoning. It does not destroy bacterial toxins, however, and may destroy vitamins. Irradiation does not render food radioactive.... irradiation of food

Skin Allergy

Irritation of the skin following contact with a specific substance that provokes an inappropriate or exaggerated reaction from the immune system. There are 2 main types of allergic skin reaction. In contact allergic dermatitis, red, itchy patches develop a few hours to 2 days after contact with the allergen. In contact urticaria, red, raised areas appear a few minutes after skin contact. In some cases, skin tests are needed, to identify the allergen, for contact with it to be minimized. (See also atopic eczema.)... skin allergy

Food And Drug Administration

(FDA) in the USA, the federal agency within the *Department of Health and Human Services responsible for ensuring that foods are safely edible; that medications (for humans and animals), biological products, and medical devices are safe and effective; and that cosmetics and electronic products that emit radiation are safe. The FDA is also responsible for ensuring the accuracy of the advertisements and labelling related to these products.... food and drug administration

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