Transcript Allergies and food intolerances

ALLERGIES
AND
FOOD
INTOLERANCES
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; and
o 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 Allergy
o Drug Reactions (eg, antibiotics, pain killers or
anaesthetics)
o Latex allergy
o Stinging insect allergy
o Urticaria/angioedema (hives, swellings)
o Atopic eczema
o Anaphylaxis (serious allergic reactions)

Disorders usually managed by allergy specialists:
o Non-allergic (vasomotor) rhinitis
o Non-allergic adverse food reactions (food
intolerance)

Overlapping disorders sometimes co-managed
with other specialties:
o Chronic sinusitis
o Nasal polyps
o Aspirin triad (nasal polyps, late onset asthma, aspirin
allergy)
o
Eosinophilic oesophagitis and gastroenteritis
o Coeliac disease
o Contact allergic dermatitis
o Sarcoid


Non-allergic disorders often erroneously attributed
to allergy
o Migraines
o Irritable bowel syndrome
o 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
o
o

Classic – itching, reddening of the skin,
asthma, swelling, choking, and a runny nose
GI Tract – nausea, vomiting, diarrhoea,
intestinal gas, bloating pain, constipation, and
indigestion
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 sensitivity.

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 examination
o Look for signs of an allergic reaction (rash,
itching, intestinal bloating etc)

Elimination diet
o Establish a diet lacking the suspected offending
foods and stay on it for 2 to 3 weeks or until the
symptoms are clear

Food challenge
o 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
chemicals or even insect parts
antibiotics,

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.
(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)

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.

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

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.

The specific types of foods and beverages that can
induce IBS symptoms include:
o milk and milk containing products
o caffeine containing products
o alcoholic beverages
o Fruits and fruit juices
o Spices and seasonings
o diet beverages, diet foods, diet candies, diet
gum
fast foods, fried foods and fatty foods
o Condiments, gravies, spaghetti sauce,
o multigrain breads, sourdough breads, bagels
o Salads and salad dressings
o Vegetables, beans
o red meats, stews, nuts, popcorn
o high fibre
o cookies, crackers, pretzels, cakes, and pies.
o

The types of foods and beverages that are better
tolerated include:
o water
o Rice, plain pasta or noodles
o baked or boiled potatoes
o white breads
o plain fish, chicken, turkey, or ham
o eggs
o dry cereals
soy or rice based products
o peas
Applesauce, cantaloupe, watermelon, fruit
cocktail
o margarine
o Jams, jellies, and peanut butter.
o
o
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 crosscontamination 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, Canberra
Jamison,J (2003) Clinical Guide to Nutrition and Dietary Supplements in Disease
Management, Churchill Livingstone
McGuire,K & Beerman,K, (2007) Nutritional Sciences: From Fundamentals to
Food, Thomson
Rolfe,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, Cengage
www.aihw.gov.au
http://www.allergy.org.au/images/stories/pospapers/2007_economic_impact_aller
gies_report_13nov.pdf