Health Tips and Hints - A Short Article Packed with
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Allergies - Symptoms and Treatments
What is an allergy?
An allergy is a sensitivity to a substance that does not usually cause people
any discomfort or harm. Hay fever, which is caused by a sensitivity to pollen,
is a well known example. Asthma, eczema, rashes and a variety of other complaints
can be caused partly or entirely by an allergy. In fact, allergies can affect
almost any part of the body and be caused by a vast range of natural and artificial
substances.
Allergies are a reaction to allergens, a name given to those substance such
as pollen that spark off symptoms of an allergy in someone who is sensitive
to it.
An allergy is everything from a runny nose, itchy eyes and palate to skin rash.
It aggravates the sense of smell, sight, tastes and touch causing irritation,
extreme disability and sometimes fatality. It occurs when the body's immune
system overreacts to normally harmless substances.
Allergy is widespread and affects approximately one in four of the population
in the UK at some time in their lives. Each year the numbers are increasing
by 5% with as many as half of all sufferers being children.
Symptoms
Symptoms of an allergy tend to show up in/on the parts of the body that are
exposed to the allergen. An airborne allergen like pollen, makes it severest
impact in the eyes, nose and air passages.
Skin allergies
There are three basic forms of allergic reaction affecting the skin. The most
common especially among children is eczema. Dermatitis is a particular type
of eczema affecting adults. This is caused by direct skin contact with certain
allergens.
Eye and ear allergies
Allergic reactions can also affect the eyes. Theses generally show up as irritation
and redness in the white of the eye. Severe swellings can occur but, but more
often then not the symptoms are watering and soreness.
The ears are also often affected by allergens, when this happens the fluid will
build up inside the ear and may temporarily affected your hearing.
Nasal allergies
Hay fever can affect the eyes and ears though the its principal target is the
nose, which becomes stuffy, runny or sneezy.
Some people suffer from symptoms which are similar to those of hay fever, and
will suffer with them all year round. They may have a stuffy, runny nose virtually
all the time, although it will often be worse indoors, particularly at night
and early morning. This condition is called Perennial rhinitis and can be the
result of an to the common house dust mite.
Food allergies and food intolerance
These have a wide variety of symptoms. The most obvious symptoms of an acute
food allergy are a stomach upset followed quickly by nausea, vomiting or diarrhoea.
People who are acutely sensitive to a food may also get a swollen tongue and
lips. Sometimes the suffer gets 2 kinds of symptoms; for instance a child who
is allergic to cow's milk may get diarrhoea and a skin rash. Apart from skin
rashes, which may appear hours or even days later after eating the food these
symptoms become apparent almost immediately after eating, usually within an hour.
This makes it quite easy for the sufferer to identify the allergen.
Recurrent tummy pains and hyperactivity in children have been attributed to
food allergies.
The most severe - though fortunately, quite rare - symptom caused by allergy
is anaphylaxis. In this instance, the patient's air passages swell and close
and the blood pressure falls abruptly. This is an acute and life threatening
condition, though it can be reversed very quickly by an injection of adrenalin.
Causes
The basic difference between people who suffer from allergies and those who
do not is still not known. Allergies do tend to run in families - and it is
very common for people to develop hay fever, childhood eczema and asthma (a
combined condition known as atrophy). This may be due to an inherited characteristic
in the cells which make up the immune system, which is the body's defence system
against disease.
Most allergies are are the result of an error in the immune system. The body's
defence forces react to the allergen as if it were a dangerous infected organism.
White blood cells called lymphocytes are one of the most important elements
of the immune system. Theses cells are constantly on the look-out for foreign
substances such as bacteria, viruses and proteins which are different from the
body's own proteins and which may present a threat. When these white blood cells
come across a potentially dangerous foreign protein they form a substance called
an antibody, which combines with the foreign protein and neutralizes it.
By some highly complicated process, which is not yet understood by scientists,
the immune system of a normal healthy person knows how to tell the difference
between a dangerous foreign protein (like a virus) and a harmless one, such
as food protein. But in an allergic person the immune system reacts to a harmless
foreign protein as if it were a dangerous one, and starts forming an antibody.
This antibody attaches itself to cells called mast cells. Mast cells contain
a number of chemicals the most important of which is histamine.
When the body is exposed to the protein again, the antibody attached to the
mast cells combines with the foreign proteins and tries to neutralise them. But
in so doing, it upsets the structure of the mast cell, which falls apart and
releases its load of histamine. The surge of histamine produces an effect very
much like the inflammation which follows a wound; it makes tiny blood vessels
dilate and they dilate their walls become leaky, so that fluid from the blood
escapes into the surrounding tissues. The dilation of the tiny blood vessels
causes redness and itching, and the escaping fluid makes the surrounding tissues
swell. In hay fever the mucous glands in the nose and sinuses are also stimulated
to produce fluid, which causes stuffiness and a runny nose.
Diagnosis
Skin prick test
In this test a small needle is used to gently prick the skin through a drop
of fluid containing a known allergen. It is usually done on the forearm, although
with young children it may be done on the back so they don't have to see what
is happening. The test is not painful and results are immediately available.
Blood test
In this test, a sample of your blood is taken and sent to a specialist laboratory
for what is known as the RAST test (Radio AllergoSorbent Test) or CAP-RAST.
This measures the amount of specific Immunoglobulin E antibodies (IgE) in your
blood to various environmental and food allergens. House dust Mite IgE will
be raised if you have an allergy to house dust mites and this is then graded
0 to 6 depending on the level of that IgE in the blood.
Patch test
This test is used to diagnose delayed allergic reactions such as Contact Dermatitis.
It involves taping traces of various known contact allergens on the skin underneath
special aluminium discs and keeping them there for 48 hours. It can test for
allergy to Rubber, Nickel, Lanolin, dyes, cosmetics, solvents, preservatives,
and medication. The test patches on the skin are then assessed for allergic
eczematous changes by a dermatologist.
A special diet called the elimination diet is sometimes used to identify which
foods are the cause of a food allergy. At first a very plain diet is provided
often consisting of little more than water and one vegetable such as potatoes
and one meat such as lamb. All possible allergens are excluded.
Treatment
If you have the acute kind of allergy that makes you sick whenever you eat say,
strawberries or shellfish, you hardly need a doctor to diagnose your complaint.
The cause and effect are obvious, and the simplest way to deal with the allergy
is to avoid the allergen.
If your doctor carries out prick tests, he/she will be able to tell you which
substance you should avoid. So if, for example you are allergic to wool, then
you should avoid contact with it.
Several kinds of drug are prescribed to deal with the symptoms of allergy.
Antihistamines combat the inflammatory effects of histamine when it is released.
They come as tablets, liquid medicine, nose drops or eye drops, and there are inject able antihistamines which can be used to deal with serious attacks. Antihistamines
are particularly useful for hay fever, urticaria and perennial rhinitis.
Another drug Disodium cromoglycate (better known as Intal), works by preventing
the mast cells from exploding. This drug can be given in the form of an inhalant
(for asthma), eye drops (for allergic symptoms in the eyes), tablets (for stomach
allergies) or by a nose spray for hay fever or perennial rhinitis.
Corticosteriod drugs such as Cortisone, which are very powerful and anti-inflammatory,
are some times prescribed for skin allergies or via an inhaler, to combat asthma.
Food allergies can sometimes be relieved by drugs, but some doctors prefer
to recommend diets which ensure that you eliminate all the foods to which you
have an allergic reaction. This can be quite difficult in the case of peanut
allergy, which can be severe and most usually occurs in children. You should
inform your child's school if your child has an allergy to nuts as peanut oil
is a commonly used cooking ingredient in many foodstuff.
Self-help
There is quite a lot you can do to help yourself or your child. Obviously if
you suffer from a food or chemical allergy you should make every effort to avoid
your allergens. (Reading the labels on food packets to see if the product contains
the allergen you are allergic to).
Hay fever sufferers should be careful about going out in the open air during
the pollen season, especially in mid-afternoon when the pollen count is highest.
Dark glasses can protect your eyes against pollen or spores.
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