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.
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.
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.
Eczema
Skin disorder causing reddening, itching, swelling and scaling. Can occur
for various reasons, including exposure to allergens.
Epinephrine
See Adrenaline
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
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.
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.
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.
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.
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 theallergen 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.
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.
Urticaria
Urticaria, also called "hives", is an inflammation
of the skin - an itchy rash.
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.
