ALLERGIES ALLERGIES ANDAND

FOOD FOOD INTOLERANCESINTOLERANCES

1

DEFINITIONS ALLERGEN – a foreign protein or antigen that

induces excess production of certain immune system antibodies. Subsequent exposure leads to the allergic response. Can cause a rapid increase in heart rate and difficulty in breathing.

FOOD INTOLERANCE – an adverse reaction that does not provoke an allergic reaction

FOOD SENSITIVITY – a mild reaction to a substance that may be expressed as a light rash or itching

Allergies and intolerances have reactions such as sneezing, coughing, nausea, vomiting, diarrhoea, hives, rashes, behaviour problems, headaches, tension and fatigue, asthma, swelling, choking, runny nose, sinus and/ or hayfever

The most common causes are peanuts, tree nuts, shellfish, milk, eggs, soybeans, wheat and fish. Also causing difficulties are meat and some meat products, cheeses, and fruits. These products contain acid like proteins that stimulate the production of antibodies in susceptible people.

Allergies are chronic immunological disorders that occur when a person's immune system mounts an abnormal response to substances in the environment (allergens) that do not normally bother other people. Allergies are grouped as: o allergic rhinitis (hay fever) and conjunctivitis;o allergic asthma;o allergic chronic sinusitis; o other allergies, which include food, drug,

latex, sting and bite allergies, urticaria (hives, nettle rash), contact dermatitis and anaphylaxis, among other disorders.

Allergies can cause significant discomfort, affect sleep, and impair learning, memory and behaviour in children.

In children with severe food allergy, management in the community is complex and has the potential to cause anxiety within affected families regarding care in schools, risk of death and the need or otherwise for injectable adrenaline.

For affected adults, allergic disorders can lead to impaired quality of life, absenteeism from work, other reduced productivity, aids (especially self-care aids such as dressings for atopic eczema) and home modifications (eg, to prevent or reduce allergen levels in the home).

Most patients with allergic disorders have associated comorbidities. The relative risk of death in people with allergic disorders is slightly elevated.

Prevalence of allergies in Australia

Australia and New Zealand have among the highest prevalence of allergic disorders in the developed world. This report estimates that in 2007:o 4.1 million Australians (19.6% of the

population) have at least one allergy, of which 2.2 million (55%) are female and 1.9 million (45%) are male;

o the highest prevalence of allergies is in the working age population, with 78% of people with allergies aged 15 to 64 years;

o there are 7.2 million cases of allergy.

In 2007, the financial cost of allergies was $7.8 billion. Of this:o $5.6 billion (72%) was productivity lost

due to: lower productivity while at work –

($4.2 billion); lower employment rates ($1.1 billion); absenteeism and lost household

productivity ($196 million); premature death, including employers’

search and hiring costs ($84 million).

$1.2 billion (15%) was the direct health system expenditure of which: o allergic asthma was an estimated $808

million; ando non-asthma allergy (NAA) was an estimated

$349 million; o $262 million (3%) was other indirect costs

such as aids and home modifications and the bring-forward of funeral costs;

o $783 million (10%) was the deadweight loss from transfers including welfare payments (mainly Disability Support Pension and Carer Payment) and taxation forgone.

To put this financial cost in perspective, it is more than twice as large as schizophrenia ($1.8 billion) and bipolar affective disorder ($1.6 billion) combined. Additionally, the net value of the lost wellbeing (disability and premature death) was a further $21.6 billion.

For 156,144 Disability Adjusted Life Years (DALYs). This represents almost double the same figures for either arthritis or hearing loss (both $11.7 billion).

If the burden of disease (the economic cost of disability and premature death) is included, individuals bear 86% of the costs. Total cost shares are depicted in the following charts.

TYPES OF ALLERGY Classical Allergic Disorders

o Allergic rhinitis (hay fever)o Asthma

o Food Allergyo Drug Reactions (eg, antibiotics, pain killers

or anaesthetics)o Latex allergy

o Stinging insect allergyo Urticaria/angioedema (hives, swellings)

o Atopic eczemao Anaphylaxis (serious allergic reactions)

Disorders usually managed by allergy specialists:

o Non-allergic (vasomotor) rhinitiso Non-allergic adverse food reactions

(food intolerance)

Overlapping disorders sometimes co-managed with other specialties:

o Chronic sinusitiso Nasal polyps

o Aspirin triad (nasal polyps, late onset asthma, aspirin allergy)

o Eosinophilic oesophagitis and gastroenteritis

o Coeliac diseaseo Contact allergic dermatitis

o Sarcoid

Non-allergic disorders often erroneously attributed to allergy

o Migraineso Irritable bowel syndromeo Chronic fatigue syndrome

Autoimmune disorders: o Vasculitis

o SLE/Systemic Lupus Erythematosus

Symptoms and mechanisms

Allergic reactions to food are quite common and occur more frequently in females than in males.

Food allergies occur most frequently during infancy and young adulthood. Experts estimate that up to about 1% to 2% of adults and up to about 4% to 8% of children are allergic to certain foods. Three types of reactions may occur after ingestion of problem foods by susceptible people:

o Classic – itching, reddening of the skin, asthma, swelling, choking, and a runny nose

o GI Tract – nausea, vomiting, diarrhoea, intestinal gas, bloating pain, constipation, and indigestion

o General – headache, skin reaction, tension and fatigue, tremors and psychological problems

Any reaction that is milder than these distinct allergic ones is referred to as a food food sensitivitysensitivity.

Allergic reactions vary not only in the body system affected but also in their duration, ranging from seconds to a few days. A generalised, all-systems reaction is called anaphylactic shock. This severe allergic response results in lowered blood pressure and respiratory and GI tract distress. It can be fatal.

Although any food can trigger anaphylactic shock, the most common culprits are peanuts, tree nuts (walnuts, pecans etc), shellfish, milk, eggs, soybeans, wheat and fish.

Halkin,S. 2004, `Prevention of allergic disease in childhood: clinical and epidemiological aspects of primary and secondary allergy prevention’, Pediatric, Allergy and Immunology, vol.15, no.suppl 16, pp.4-5, 9-32)

The development and expression of atopic diseases depends on a complex interaction between genetic factors, environmental exposure to allergens and non-specific adjuvant factors, such as tobacco smoke, air pollution and infections.

Preventive measures may include both exposure to allergens and adjuvant risk/protective factors and pharmacological treatment.

The combination of atopic heredity and elevated cord blood IgE resulted in the best predictive discrimination as regards development of allergic disease.

A few ongoing prospective, randomized intervention studies have produced the first indication that avoidance of indoor allergens such as house dust mite (HDM) in HR infants may reduce the incidence of severe wheeze and sensitization during the first 1-4 years of age. Long-term follow-up is awaited.

In a prospective, double-blind placebo-controlled study in children with doctors diagnosed asthma and documented HDM allergy, we found that semipermeable polyurethane mattress and pillow encasings (Allergy Control) when compared with placebo encasings resulted in a significant perennial reduction of HDM exposure and a significant reduction in the needed dose of inhaled steroids by approximately 50% after 1-year follow-up.

In another randomized prospective study we investigated the possible preventive effect of specific immunotherapy (SIT) in children with allergic rhinoconjunctivitis and grass pollen allergy as regards development of asthma.

Among those without asthma, significantly fewer in the SIT group developed asthma when compared with the control group.

The results of these studies support the evidence that the risk for development of early allergic manifestations e.g. cows milk allergy (CMA) and atopic dermatitis can be reduced significantly by simple dietary measures for the first 4 months of life.

In all infants breastfeeding should be encouraged for at least 4-6 months, and exposure to tobacco smoke should be avoided during pregnancy and early childhood.

In HR infants a documented hypoallergenic formula is recommended if exclusive breastfeeding is not possible for the first 4 months.

In homes of HR-infants, current evidence supports measures to reduce the levels of indoor allergens. e.g. HDM and pets.

In symptomatic children allergen-specific treatment may influence both the symptoms and the prognosis.o Allergen avoidance can reduce the

need for pharmacological treatment, o SIT may have the potential for

preventing the development of asthma in children with allergic rhinoconjunctivitis.

o It may be possible to interfere with the natural course of allergic diseases.

(Lance,F., Micheau,P., Marchac,V., Scheinmann,P. 2003, `Food allergy and asthma in children’, Revue de Pneumologie CLinique, vol.59, no.2 pt 1, pp. 109-13)

The links between food allergy and asthma are becoming more clear.

The association of food allergy and asthma in the same child is unusual (less than 10% in atopic subjects).

This association is however a sign of gravity leading to more severe manifestations of food allergy in asthmatic children.

Compared with the non-asthmatic child, the asthmatic child has a 14-fold higher risk of developing a severe allergic reaction to the ingestion of food. The most commonly cited foods are fruits with a rind, cow's milk and, of course, nuts.

Assessment strategy History

o Includes description of symptoms, time between food ingestion and onset of symptoms, duration of symptoms, most recent allergic episode, quantity of food required to produce reaction, suspected foods, and allergic diseases in other family members

Physical examinationo Look for signs of an allergic reaction

(rash, itching, intestinal bloating etc)

Elimination dieto Establish a diet lacking the suspected

offending foods and stay on it for 2 to 3 weeks or until the symptoms are clear

Food challengeo Add back small amounts of excluded

foods one at a time, as long as anaphylactic shock is not a possible consequence

Common causes Certain foods such as red wine, tomatoes,

pineapples that cause physiological effects such as a change in blood pressure

Synthetic compounds such as sulphates, food colouring agents and MSG

A reaction to Tartrazine, a food colouring additive

Food contaminants including antibiotics, chemicals or even insect parts

Tyramine, a derivative of the amino acid tyrosine, is commonly found in aged foods such as cheeses and red wine, can cause high blood pressure in people taking MAOI’s for depression or mental disorders

Toxic contaminants such as salmonella bacteria or clostridium botulinum or other food borne microbes

Digestive enzyme deficiency e.g. lactase

Food intolerances Food intolerances are adverse reactions

to food that do not involves allergic mechanisms. Generally, larger amounts of the offending food are required to produce symptoms of intolerance than to trigger allergic symptoms. Common causes of food intolerances include:

o Constituents of certain foods (e.g., red wine, tomatoes, pineapples) that have a drug like activity, causing physiological effects such as changes in blood pressure

o Certain synthetic compounds added to foods, such as sulphites, food colouring agents, and monosodium glutamate (MSG)

o Food contaminants, including antibiotics and other chemicals used in the production of livestock and crops, as well as insect parts not removed during processing

o Deficiencies in digestive enzymes, such as lactase

o Toxic contaminants resulting from ingestion of improperly handled and prepared food contain Clostridium botulinum, Salmonella bacteria or other food-borne microbes

o A reaction to tartrazine, a food colouring additive, includes spasm of the airways, itching and reddening of the skin.

o Sulphites, which are added to food and beverages as antioxidants, cause flushing, spasm of the airways, and a loss of blood pressure in susceptible people. Wine, dehydrated potatoes. Dried fruits, gravy, soup mixes, and restaurant salad greens commonly contain sulphites.

o A reaction to MSG may include an increase in blood pressure, numbness, sweating, vomiting, headaches and facial pressure. MSG is commonly found in Chinese foods and many processed foods e.g. soups

Tyramine, a derivative of the amino acid tyrosine, is commonly found in “aged” foods, such as cheeses and red wines. This natural food constituent can cause high blood pressure in people taking monoamine-oxidase inhibitor medications, which may be prescribed for mental depression.

Intolerance to certain foods can cause a range of gut and systemic symptoms. The possibility that these can be caused by lactose has been missed because of "hidden" lactose added to many foods and drinks inadequately labelled, confusing diagnosis based on dietary removal of dairy foods.

The key is the prolonged effect of dietary removal of lactose.

(Matthews,SB., Waud,JP., Roberts,AG., Campbell,AK. 2007, `Systemic lactose intolerance: a new perspective on an old problem’, vol.81, no.953, pp. 167-73)

Patients diagnosed as lactose intolerant must be advised of "risk" foods, inadequately labelled, including processed meats, bread, cake mixes, soft drinks, and lagers.

This review highlights the wide range of systemic symptoms caused by lactose intolerance.

This has important implications for the management of irritable bowel syndrome, and many other specialties.

The basic treatment for food intolerances is to avoid specific offending components. However, total elimination is often not required because people generally are not as sensitive to compounds causing food intolerances as they would be to allergens. For instance, a slight amount of sulphites in a glass of red wine may be tolerated whereas a large amount of chef’s salad may cause a reaction.

Irritable bowel syndrome (IBS) with chronic inflammatory bowel disease (IBD) is a difficult but important challenge to recognize and treat.

Because of the underlying chronic inflammation in IBD, IBS symptoms occur with increased frequency and severity, secondary to increased hypersensitivity to foods and beverages that stimulate the gastrointestinal tract.

The adverse effects of many foods and beverages are amount dependent and can be delayed, additive, and cumulative.

IRRITABLE BOWEL SYNDROME

The specific types of foods and beverages that can induce IBS symptoms include:

o milk and milk containing productso caffeine containing products

o alcoholic beverageso Fruits and fruit juiceso Spices and seasonings

o diet beverages, diet foods, diet candies, diet gum

o fast foods, fried foods and fatty foodso Condiments, gravies, spaghetti sauce, o multigrain breads, sourdough breads,

bagelso Salads and salad dressings

o Vegetables, beanso red meats, stews, nuts, popcorn

o high fibreo cookies, crackers, pretzels, cakes, and

pies.

The types of foods and beverages that are better tolerated include:

o watero Rice, plain pasta or noodleso baked or boiled potatoes

o white breadso plain fish, chicken, turkey, or ham

o eggso dry cereals

o soy or rice based productso peas

o Applesauce, cantaloupe, watermelon, fruit cocktailo margarine

o Jams, jellies, and peanut butter.

Reading food labels

As of 2006, food labels have been required to list the presence of common food allergens in plain language, using the names of the 8 most common allergy causing foods.

For example:o a food containing “textured vegetable

protein” must say “soy” on its label;o “casein” must be identified as “milk”

Food producers must also prevent cross-contamination during production and clearly label foods in which it is likely to occur:

o E.g. equipment used for making peanut butter must be scrupulously cleaned before being used to pulverise cashew nuts for cashew butter to prevent consumers from peanut allergens.

Treatment of food allergies

REMOVE FROM THE DIET – however ensure that nutrient balance is not compromised.

Allergens can cross the placenta during pregnancy and can be secreted in the breast milk.

Many children with food allergies outgrow them within 3 – 5 years.

Many older children and adults lose their allergy in time.

For others, it will most probably be lifetime.

Perform regular food challenges

o Milk allergies: Foods that are labelled “non-dairy” may contain the milk protein lactose;

A milk allergy may be difficult to distinguish from lactose intolerance.

o Egg allergies: Because flu vaccines are prepared using egg embryos, people with egg allergies need to check before being vaccinated.

o Peanut allergies: People with peanut allergies should avoid all nuts due to potential contamination from food processing

o Reevaluation of food allergy may require oral challenges and skin prick tests, although substantial caution is necessary in people who experienced severe allergic reactions after consuming certain foods.

Reference list:Australia’s Health 2010, a publication by the Australian Institute of Health and Welfare, CanberraJamison,J (2003) Clinical Guide to Nutrition and Dietary Supplements in Disease Management, Churchill LivingstoneMcGuire,K & Beerman,K, (2007) Nutritional Sciences: From Fundamentals to Food, ThomsonRolfe,S, Pinna,K & Whitney,E (2009) Understanding Normal and Clinical Nutrition 8th Edition, Cengage Whitney,E, Rolfes,S, Crowe,T, Cameron-Smith,D & Walsh,A (2011) Understanding Nutrition, Cengagewww.aihw.gov.au http://www.allergy.org.au/images/stories/pospapers/2007_economic_impact_allergies_report_13nov.pdf