A
Adrenaline
Adrenaline (or epinephrine) is a hormone produced by the kidneys in response
to an emergency situation
anaphylaxis .
Adrenaline makes the heart beat faster, narrows the blood vessels and
dilates the airways.
Allergen
A protein molecule (antigen) that can trigger the immune system to produce
antibodies and thereby
cause an allergic reaction. Examples are proteins in pollen, house dust
mites and animal dander (dead skin cells).
Allergen extract
A fluid containing allergens extracted from natural sources (e.g. trees,
grass, cat hair and dander) to a defined standard, quality and quantity.
Used in
specific allergy vaccination,
skin prick tests,
provacation tests
and in vitro tests.
Allergy
Hypersensitivity of the immune system to a natural substance that does not
cause symptoms in non-allergic people. Examples of allergic illnesses are
hay fever,
urticaria,
asthma and
contact
dermatitis. Allergy can be seasonal - e.g. allergy to pollen (hay fever)
- or occur all year round - e.g. allergy to animals or dust.
Anaphylaxis
Also known as anaphylactic shock. An acute allergic reaction. Symptoms occur
immediately after exposure to an allergen (e.g. insect stings) and include
diarrhoea, bleeding, vomiting, bronchospasm and breathing problems. If you
experience these or similar symptoms, seek immediate medical assistance,
because anaphylaxis can cause loss of consciousness and even death.
Anaphylactic reactions can be reversed with
adrenaline. If you
have already experienced an anaphylactic shock, consider starting
specific
allergy vaccination and always carry a device containing adrenaline (e.g
EpiPen).
Antibody
Antibodies (or immunoglobulins) are proteins in blood and body fluid.
Antibodies are produced by
B-cells when these are triggered by an allergen. Antibodies recognise
foreign substances (e.g. bacteria) and bind to their surface, thereby
helping the immune system to destroy them. There are five different classes
of antibodies. Immunoglobulin E
IgE is of importance in allergy.
Antigen
See allergen.
Antihistamine drugs
Histamine is released by
mast cells in body tissue as a response to an
allergen and gives
rise to the symptoms of an allergic response. Antihistamine drugs influence
(reduce) the release of
histamine. Antihistamine drugs come in various forms (liquid or powder
for the nose, eye drops or tablets) and can provide instant relief from the
symptoms, depending on the severity of the attack.
Asthma
A chronic lung disease characterised by
inflammation which
destroys lung tissue and by contraction of the smooth muscles cells lining
the bronchi, making it
difficult to breathe. Asthma can be either allergic or non-allergic.
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B
B-cell
B-cells (or B-lymphocytes) are white blood cells that produce and secrete
antibodies into the
blood. See also Cell
memory.
Bronchitis
Inflamation in the bronchi,
resulting in coughing and the production of sputum. Can be caused either by
an infection or an allergy.
Bronchi
The branching airways of the lungs.
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C
Causal treatment
A form of treatment which deals with the cause of a disease, not only the
symptoms.
Specific
allergy vaccination is a causal treatment, the use of
antihistamines
is a
symptomatic treatment.
Cell memory
If foreign substances (e.g. bacteria) enter the body, the immune system
reacts by attacking and killing them. At the same time,
T-cells and
B-cells produce a
population of memory cells. If you are subsequently exposed to the same
bacteria, the immune system reacts much more quickly. In allergy, this
mechanism is called "priming". You do not experience an allergic reaction
the first time you are exposed to a particular allergen, but your body
registers the allergen and, over time, you may develop an allergy to it.
Challenge test
See Provocation test
Contact dermatitis
A rash or inflamation
of the skin. As the term indicates, you develop an allergy to something that
comes into contact with your skin. Many things in everyday life can provoke
contact dermatitis - e.g. rubber gloves or the nickel in your buttons or
watch.
Corticosteroid drugs
Anti-inflammatory drugs that interfere with the immune system, suppress it
and thereby dampen the inflammatory overreaction. They can be used to treat
a number of allergic diseases - e.g. allergic
rhinitis, eczema and
rheumatoid arthritis. Corticosteroid drugs come as creams, inhalants,
tablets and eye drops.
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E
Eczema
Skin disorder causing reddening, itching, swelling and scaling. Can occur
for various reasons, including exposure to allergens.
Epinephrine
See Adrenaline
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H
Hay fever
See Rhinitis.
Histamine
A biologically active substance released from
mast cells during an allergic reaction in response to an
allergen. Histamine
causes running nose, sneezing and itching, and narrows the airways in the
lungs. Antihistamines can be used to block the release of histamine that
would otherwise occur as a result of exposure to an allergen.
Hives
See Urticaria.
Hyposensitisation
See
specific allergy vaccination.
Hydrocortisone
See
Corticosteroid drugs
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I
IgE
IgE (ImmunoglobulinE) is the
antibody produced in
excess in allergic patients. IgE can be measured in a blood sample to
determine if a person is allergic. Allergic people usually have high levels
of IgE.
Immune system
A system of organs that react to foreign agents (e.g. bacteria, virus and
moulds), thereby protecting the body. The immune system consists of thymus,
bone marrow, lymph nodes and spleen. In allergic people, the immune system
overreacts to harmless agents.
Immunoglobulins
See Antibody.
Immunotherapy
See
specific allergy vaccination.
Inflammation
A reaction to an injury to the body - by infection, chemicals or physical
agents. The symptoms can be - depending on the location of the injury-
redness, swelling, heat and pain. The purpose of the inflammation is to
dilute and destroy the agent causing the inflammation. To do this, the
immune system starts a cascade of actions that causes active cells to gather
at the affected location. It is these cells and fluids that cause the
redness, swelling, heat and pain.
Interleukin
Messenger molecule between the different cells of the
immune system.
Intolerance
When the body reacts inappropriately but non-allergically (i.e. without
IgE production) to a particular substance. Many people experience
reactions to certain types of food. Of these, 2-3% are allergic to the foods
concerned; the rest experience intolerance.
Intracutan test
Intracutan tests are used to diagnose allergies. A small amount of
allergen extract
is injected under the skin on your arm. If the area becomes itchy, reddish
and swelling you may have an allergy.
In vitro
What goes on in a test tube, e.g.
IgE determination in a
blood sample. The opposite of in vivo.
In vivo
In vivo means 'in the living organism', i.e. examination of the living
organism - for example, a
skin prick test.
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M
Macrophage
A large cell that acts as a scavenger, helping the
immune system to destroy foreign agents.
Mast cell
Mast cells are found all over the body, especially in connective tissue such
as the skin.When exposed to an
allergen, the mast
cell releases histamine
and other related substances.
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P
PEF (Peak Expiratory Flow)
A measurement of lung function, established by the patient's blowing into a
special device. The higher the number recorded, the better the lung
function. PEF is dependent on the severity of the disease, gender, age and
height. A lower reading than expected may be caused by an allergy.
Pollen
Pollen is the male fertilising agent of flowering plants, grasses, trees and
weeds.
Provocation test
Also called a challenge test. A testperformed on eyes, nose or lungs and
used to diagnose an allergy or monitor the effect of e.g.
specific
allergy vaccination. The allergen is introduced in increasing doses to
the organ to see if the person reacts and, if so, at what level of exposure.
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R
Rhinitis
Rhinitis is
inflamation of the cells lining the nose resulting from the inhalation
of an allergen. The
symptoms include nasal obstruction, runny nose and sneezing. Rhinitis can be
seasonal, e.g. allergy to pollen (hay fever), or all yearround - e.g.
allergy to animals or dust.
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S
Skin prick test
Skin prick tests are used to diagnose allergies. Pricking gently through a
drop of allergen
extract placed on the surface of the arm may result after 10-15 minutes
in the appearance of a small, itchy swelling and a reddening of the skin.
This indicates an allergy.
Specific allergy vaccination
Specific allergy vaccination is also called specific immunotherapy,
hyposensitisation or allergy shot. It is a vaccination programme that
affects the natural course of an allergic disease, not only its symptoms.
When the patient is given increasing doses of the
allergen to which he
or she is allergic, the
immune system
becomes less sensitive and the patient no longer reacts. Two different types
of vaccine exist: a depot (slow-release) preparation and an aqueous
solution.
Shots
See
specific allergy vaccination.
Steroids
See
corticosteroid drugs
Symptomatic treatment
A treatment with drugs that only affects the symptoms of the disease, not
its cause - e.g.
antihistamines and
corticosteroids.
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T
T-cell
T-cells or T-lymphocytes (white blood cells) determine together with
interleukins which class of
antibodies is to be produced by the
B-cells. See also
Cell memory.
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U
Urticaria
Urticaria, also called "hives", is an
inflammation of the skin - an itchy rash.
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ß
ß2-agonist
ß2-agonists are used in the treatment of asthma and chronic obstructive lung
disease (COPD) and are used to relax the smooth muscles in the
bronchi, which contract during an asthma attack. ß2-agonists are
available in short-acting and long-acting formulations for inhalation and as
tablets.
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