NEWS 4

ALLERGY

 

Introduction

To help you get the most out of this article, I have arranged the content of the article as follows:-

- 1. What is allergy

- 2. How widespread is allergy

- 3. What are some of the most of allergy

- 4. Allergic Symptoms

- 5. What cause the allergic symptoms (pathophysiology)?

- 6. Treatment

- 7. Prevention

With this GPS (Global Positioning System) to guide you, you can get to the topic that interest you
quicker.

1. What is allergy?

Allergy is a disorder of the immune system. More specifically, it is an abnormality of a part of the
immune system. Allergy happens when a part of the immune system react to a common and
otherwise harmless everyday object. This form of allergy is also known as Type 1 Hypersensitivity.
We will concentrate our effort on Type 1 hypersensitivity of which there are several kinds.

Allergy is an inheritable disorder. If both parents have allergy, their siblings will likely have allergy,
but the exact kind of allergy need not be the same as those of the parents. For example, the parents
could be allergic to pollens and molds, but he sibling could be allergic to animal danders. In
addition, it is seldom to find a person suffering from only one kind of allergy provoking agent
(allergen). More often than not, allergens of several kinds of plants or grass could elicit allergic
reaction in the same person.

There is no known cure for allergy in conventional medicine. There have been unconfirmed claims
of cure with the use of traditional Chinese medicine. Nevertheless, avoiding allergens and if
necessary supplemented by the use of medicine could prevent or reduce to a large extent, the
outbreak of allergic reactions and improve the quality of life.

 

2. How widespread is allergy?

According to research data (gathered during the last 30 years) allergic diseases prevalence tends to
double every ten years. Currently, one in four persons in the industrialised countries suffer from one
or another kind of allergy. The WHO (World Health Organisation) now classifies allergic diseases
as the fourth most common disorders in the world. Furthermore, these disorders represent “a major
health problem” in terms of quality of life, days of work or of school missed, drug-related cost or
even mortality.

 

3. What are some of the most common forms of allergy?

Pollen allergy: is one of the most common kind of allergy worldwide. In the US more than half the
people with allergy suffer from pollen allergy. Pollen allergy is also known as seasonal allergy or
allergic rhinitis. Perhaps the best known name for pollen allergy is hay fever.

Pollens are air-born microscopic particles. The process of shedding pollens in the air is known as
abiotic pollination which is necessary for reproduction of the plants or grass. This is especially true
for plants with less spectacular flowers and grass such as ragweed.

With each inhalation (breathing-in), these microscopic pollens get deposited on the mucous
membrane (inner lining) of the sinus (nasal) and on the mucous membrane of the inner lining of the
airways or the bronchioles. These allergens then provoke through the abnormal immune system, a
cascade of cellular reactions which cause the release of chemicals (mediators) that are responsible
for the allergic symptoms.

House dust (mite) allergy: Coming in contact with “house dust” causes the outbreak of allergic symptoms in some people. Theso-called house dust is actually composed of a mixture of several substances and vary from home to home. In addition to animal danders and spores from molds, the following are also frequently found
(in the dust):

Dust mite allergy is one of the most common form of allergy. Mites survive on dead skin, danders
and grow in rooms with relative high humidity with temperature above 20° C or above 68° F. The
actual cause of dust mites are the remains of the mites and their faeces. The greatest numbers of
dust mites can be found in carpets, which provide the best conditions (warmth, humidity and food)
for their growth. Mites are also present in mattresses, pillows, blankets, upholstered furniture,
curtains and similar fabrics. Female mites can lay 25 to 50 eggs, with a new generation produced
every three weeks. It is therefore easy to see why carpets may contain such large numbers of living
and dead mites.

Cockroaches: Dust containing parts of cockroaches which include skin casts, feces and other parts
of the cockroach. These are the allergens that cause allergic reactions to the cockroach.
Cockroaches are very difficult to exterminate. Keeping a clean house and making sure that that no
food particles or left overs will reduce cockroach population and help reduce allergy to
cockroaches.

Animal and pet allergy. Many people believe that it is the hair of the animal which provoke the allergic symptoms. Theoffending substance (allergen) is actually the danders (dead skin), saliva on the hair and urine thatcause the outbreak of the allergic symptoms. From 15 percent to 30 percent of people with allergies
have allergic reactions to cats and dogs.

House pet allergy is easier to control by keeping the pet outside the house or keeping it at least from
the bedroom and removing the clothes you wore after playing with the pet. In addition, keeping the
pets from furniture, vacuum cleaning both the furniture and the carpet will help to further reduce the
offending allergen.

Dogs and cats are the most common animal allergy. However, other animals such as horses, birds,
rabbits, guinea pigs and others can also be a source of allergy.

Mold allergy: Molds, a subset of the fungi, are ubiquitous on our planet. Fungi are found in every ecological
niche, and are necessary for the recycling of organic building blocks that allow plants and animals
to live. Included in the group "fungi" are yeasts, molds and mildews, as well as large mushrooms,
puffballs and bracket fungi that grow on dead trees. Fungi need external organic food sources and
water to be able to grow.

Molds can grow on cloth, carpets, leather, wood, sheet rock, insulation (and on human foods) when
moist conditions exist. Since molds grow in moist or wet indoor environments, it is possible for
people to become exposed to molds and their products, either by direct contact on surfaces, or
through the air (e.g., spores and fragments).

Many molds reproduce by making spores, which, if they land on a moist food source, can grow and
begin producing a branching network of cells called hyphae. Indoor spaces that are wet, and have
organic materials that mold can use as a food source, will promote mold growth. Mold spores or
fragments that become airborne can expose people indoors through inhalation or skin contact.

Molds can have an impact on human health apart from causing allergy, depending on the nature of
the species involved, the metabolic products being produced by these species, the amount and
duration of individual’s exposure to mold parts or products, and the specific susceptibility of those
exposed.

Stachybotrys chartarum is a greenish-black fungi and defends itself from rival microorganisms by
releasing poisons called mycotoxins, and can cause serious illness in humans. Mycotoxins tend to
inhibit protein synthesis, which your body needs to survive, they can cause hemorrhaging in various
parts of the body.

The musty, moldy odor comes from volatile organic compounds, which are mainly alcohols and
ketones,and inhaling alcohol for a long time, in sufficient quantity, can result in headaches, watery
eyes, mucous membrane irritation which can affect anyone.

Mold and mildew allergy spread through airborne spores. The spores are deposited on the mucous
of the nasal passages, the eyes and the mucous linings of the bronchi (airways) and when that
happens, persons having mold allergy will produce the allergic symptoms. Even dead spores can
cause allergic reactions. So it's essential that mold be scrubbed away after it's killed. Mold can hide
within your home's crevices and behind cardboards.

Contact dermatitis: There are many different chemicals which could cause allergy and they are mostly contact allergy. Some common examples of the cause contact dermatitis are:

- Latex

- Poison Ivy

- Nickel

- Chemical components in rubber gloves

- Dyes

- Preservative chemicals added to cosmetics, moisturizers and topical medications

- Formaldehyde

- Fragrances

Allergy to drugs

A drug allergy occurs when your immune system reacts to a medication. A number of drugs can
cause a drug allergy, including prescription and over-the-counter medications. The most common
signs of a drug allergy are hives, rash or fever. You can have an allergic reaction to a drug even if it
caused no reaction in the past.

Many drugs are able to cause allergy. True drug allergy results from a series of chemical reactions
between the offending chemical and the immune system itself that cause the release of chemicals
(mediators) from the immune cells and ultimately go on to provoke the allergic response. The most
frequent culprits are the following groups of drugs:

- Sulfa drugs

- Anticonvulsants

- Insulin, especially from animal sources

- Contrast dyes containing iodine frequently used in x-ray

- Antibiotics such as penicillin

The last two categories of drugs can provoke severe and life-threatening allergic response known as
anaphylactic shock which will be considered separately below. On the other hand, many drug
related side effects are not allergic responses. It is thus more than advisable to talk to you family
doctor for clarification.

 

Food allergy: Many people are not certain about the difference between food allergy and food intolerance when they have eaten something that does not suit them and they get an unpleasant feeling in the gut.
Food allergy involves the immune system, but food intolerance does not. Therefore, food intolerance is not a true allergy and will not be considered here.

Nearly 90% of food allergy is cause by one or more of the following:

- Tree nuts (almonds, cashews and walnuts)

- Peanuts

- Eggs

- Milk

-Wheat

- Fish

- Shellfish

- Soy

People who have food allergies MUST identify and avoid them (offending food) because, although
usually not severe, these reactions can cause devastating whole body responses (anaphylactic
shock) which can be fatal.

Symptoms

Pollen allergy: The most prominent symptoms of pollen allergy are:

-Sneezing, the most common, may be accompanied by a runny or clogged nose
  Itching eyes, nose, and throat.

- Allergic shiners (dark circles under the eyes caused by restricted blood flow near the sinuses)

- Watering eyes

- Conjunctivitis (an inflammation of the membrane that lines the eyelids, causing red-rimmed eyes).

These symptoms are the most prevalent signs of hay fever. There are other symptoms. If you are not
sure, contact your allergy specialist or allergologist.

House dust mite allergy: Unlike pollen, dust mites are present all year round causing constant
allergy - 'perennial' allergic rhinitis. The excretion from the mites dries out and can be launched into
the air when someone walks over a rug, sits down in a chair, or shakes the bed clothes, giving
allergic people immediate symptoms.

You should suspect house dust mite allergy if the hay fever-like symptoms persist beyond the
pollination season. In addition to the hay fever like symptoms:

- Difficulty in breathing or wheezing (asthma)

- Coughing

- Eczema or allergic skin rash may also be present.

Animal and pet allergy: The symptoms of pets allergy are very similar to those of pollen allergy.
Often, wheezing, tightness of the chest and difficulty in sleeping due to the shortness of breath are
also present.

Mould allergy: Allergy responses to mold are very similar to those of hay fever. If the spores are
from molds outside of the house, closing the windows and the use of filters such as air conditioners
will reduce the symptoms. If the mold is in the house, the offender should be found and removed
(cleaned) to reduce the symptoms. Symptoms could also include skin rashes.

Contact dermatitis: Latex allergy is a term used to include a range of allergic reactions to natural
rubber latex, which is known to cause 2 of the 4 (or 5) types of hypersensitivity.

Type IV hypersensitivity reaction is also called delayed type hypersensitivity reaction because it
takes 2 to 3 days for the reaction to develop after exposure to the particular substance. The
symptoms resulting from this type of allergy are usually mild and affect the skin area in physical
contact with the allergen as skin rashes. Some people who are allergic to latex are also allergic to
clothes, shoes, and other things that contain natural rubber latex—for example elastic bands,,rubber
gloves, condoms, balloons, and clothing containing natural rubber, etc.

The most serious and rare form, type I is an immediate and potentially life-threatening reaction, i.e.,
anaphylactic shock, similar to the severe reaction some people have to bee sting. Such reactions
account for a significant proportion of anaphylactic reaction. The symptoms of anaphylactic shock
may include:

- Difficulty in breathing

- Dizziness

- Confusion

- Wheezing

- Nausea

- Vomiting

- Rapid or weak pulse

- Loss of consciousness

Anaphylactic shock is a medical emergency and requires IMMEDIATELY MEDICAL
ATTENTION.

Drug allergy:Symptoms of drug allergies can be mild or life-threatening and appear within 1 to 72 hours. They include:

-Hives or rash, blisters, eczema. These are the most common symptoms of drug allergies.

- Coughing, wheezing, runny nose, and difficulty breathing.

- Fever

- Anaphylactic shock which can be life-threatening. Symptoms usually appear within 1 hour after
taking the medicine. Other symptoms include hives difficulty in breathing and shock

Penicillin allergy is one of the most common drug allergy and it can be a potentially life-threatening
condition.

Food allergy: The food we eat is made up of many components. Protein is one of them. These
components are digested and absorbed into the blood stream. If you are allergic to certain foods, the
protein in the food becomes an allergen.  IF you eat this food for the very first time, there will be no allergic
reaction even though the allergen is present. IF on the other hand, you eat this food for the second
time, the allergen will make a certain immune cells to produce a huge amount of antibody which is
known as IgE (immunoglobulin E) causing the symptoms of food allergy (see Mechanism of allergy
below).

The complex process of digestion affects the timing, location, and particular symptoms of an
allergic reaction to food. All the symptoms of food allergy occur within a few minutes to an hour
after eating. A food allergy can initially be experienced as an itching in the mouth and difficulty in
swallowing and breathing. Then, during digestion of the food in the stomach and intestines,
symptoms such as nausea, vomiting, diarrhea and abdominal crampsa can follow. Incidentally, the
gastrointestinal symptoms of food allergy are those that are most often confused with the symptoms
of different types of food intolerance or food poisoning.

Anaphylactic shock: The symptoms of an anaphylactic reaction may occur within seconds of
exposure, or be delayed 15 to 30 minutes, or even an hour or more after exposure (typical of
reactions to aspirin and similar drugs). Early symptoms are often related to the skin and include:

- Flushing (feeling of warmth and redness of the skin),

- itching, and

 - hives.

These symptoms are often seen together with

- feeling of fear,

- anxiety, and

- fast and irregular pulse.

- rapid fall in blood pressure.

As the anaphylactic shock intensifies, swelling of the throat and tongue results in hoarseness,
difficulty in swallowing, difficulty in breathing and loss of consciousness (see also symptoms of
anaphylactic shock under contact dermatitis).

Treatment

Pollen allergy: There are three general approaches to the treatment of pollen allergy; avoidance of
the allergen, medication to relieve symptoms, and immunotherapy or injection treatments
(commonly called allergy shots). Although no cure for pollen allergy has yet been found, one of
these strategies or a combination of them can provide various degrees of relief from allergy
symptoms.

Avoidance

There are other ways to evade the offending pollen: remaining indoors in the morning, for example,
when the outdoor pollen levels are highest. Sunny, windy days can be especially troublesome. If
persons with pollen allergy must work outdoors, they can wear face masks designed to filter pollen
out of the air reaching their nasal passages. As another approach, some people take their vacations
at the height of the expected pollinating period and choose a location where such exposure would
be minimal. The seashore, for example, may be an effective retreat for many with pollen allergies.

Air conditioners and filters. Use of air conditioners inside the home or in a car can be quite helpful
in reducing pollen levels. Also effective are various types of air-filtering devices made with
fiberglass or electrically charged plates. These can be added to the heating and cooling systems in
the home. In addition, there are portable devices that can be used in individual rooms.

Avoiding Irritants. During periods of high pollen levels, people with pollen allergy should try to
avoid unnecessary exposure to irritants such as dust, insect sprays, tobacco smoke, air pollution,
and fresh tar or paint. Any of these can aggravate the symptoms of pollen allergy.

Medication: For people with seasonal allergies who find they cannot avoid pollen, the symptoms can often be controlled with medication available by prescription or over the counter.

Effective medications that can be prescribed by a physician include antihistamines, corticosteroids,
and cromolyn sodium - any of which can be used alone or in combination. There are also many
effective antihistamines and decongestants that are available without a prescription.

Antihistamine: As the name indicates, an antihistamine counters the effects of histamine, which, as
described before, is released by the mast cells in the body's tissues and contributes to the allergy
symptoms. For many years, antihistamines have proven useful in relieving sneezing and itching in
the nose, throat, and eyes and in reducing nasal swelling and drainage. But many people who take
antihistamines experience some distressing side effects: drowsiness and loss of alertness and
coordination. In children such reactions can be misinterpreted as behavior problems.

Nasal Decongestants: Over-the-counter products containing decongestants can be helpful in
relieving blocked nasal passages. These drugs constrict the blood vessels in nasal tissue, lessening
swelling and mucus production. Nasal decongestants, although available as nasal sprays, may be
taken orally; these include compounds such as ephedrine, phenyl-propanolamine hydrochloride, and
pseudoephedrine hydrochloride. Because these drugs can raise blood pressure, increase the heart
rate, and cause nervousness in some people, persons with allergies should check with their doctors
before using decongestants. Be aware of rebound effect.

Corticosteroid: Until recently, corticosteroids, although very effective in controlling allergic
disorders, were not widely used for pollen allergy because their prolonged use can result in serious
sided effects. Corticosteroids relieve the symptoms of pollen allergy by reducing nasal
inflammation and inhibiting mucus production. Locally active steroids that penetrate the nasal
membrane are now available as nasal sprays in measured-dose spray bottles. When used this way,
the drug affects only the nasal passages rather than the entire body. The side effects, which are
minimal when the spray is used in recommended doses, can include nasal burning and dryness and
a sore throat.

Cromolyn sodium: Another effective agent that is available by prescription as a nasal solution is
cromolyn sodium. Unlike antihistamines or steroids, cromolyn sodium is believed to control
allergic symptoms by preventing the mast cells from releasing histamine. In clinical trials, cromolyn
sodium has been proven safe and effective and, in contrast to some other allergy medications,
appears to cause no drowsiness. Unlike antihistamines and decongestants, corticosteroid nasal
sprays and cromolyn sodium nasal solutions must be used for several days to weeks before there is
any noticeable reduction in symptoms.

Combination therapy. Sometimes antihistamines, cromolyn sodium, or nasal corticosteroids are not
effective when used alone, but when prescribed in combination, these agents can often provide
significant, if not total, relief from hay fever.

Immunotherapy: If environmental control methods and medication prove to be inadequate to control a person's symptoms, a physician may recommend immunotherapy (commonly called allergy shots). The aim
of this treatment is to increase the patient's tolerance to the particular pollen to which he or she is
allergic.

Diluted extracts of the pollen are injected under the patient's skin. The patient receives small doses
once or twice a week, working up to larger doses that are given less often. The size of the largest
dose depends on the patient's tolerance and the treatment's effect on the patient's allergy symptoms.
Since it takes time to build up tolerance, prolonged treatment may be needed before the patient's
symptoms are relieved.

Immunotherapy is not without problems. It can be expensive, and may require months before
improvement is apparent. Further, it does not work well for some people and, if the size of the dose
or frequency of shots is not carefully monitored, the injections can cause allergic reactions. These
reactions can be quite mild - redness and swelling at the site of the injection - or potentially serious
systemic reactions such as hives, generalized swelling, or shock. Immunotherapy is therefore only
one part of a physician's overall treatment plan for an allergic patient.

House dust mites: What medications will be most appropriate depends on your symptoms, and how severe they are.

Nasal symptoms can be treated with nasal sprays. Nasal sprays come in many varieties.

Decongestant nasal sprays simply clear out a blocked nose. Examples of a decongestant nasal spray
include ephedrine, phenylpropanolamine, or phenylephrine. They work by acting on the nervous
system to narrow the blood vessels in your nose (vasoconstriction), which can make a nose less
blocked and also help reduce the amount of mucus. Decongestant nasal sprays can clear your nose
before you use another type of nasal spray. Care must be taken that you do not over-use these, as
this can result in a blocked nose which was worse than it was to begin with.

You can also get antihistamine nasal sprays. Examples of antihistamines are cetirizine or loratadine.
Antihistamines work by acting against histamine receptors and thus stopping histamine giving you
symptoms. Histamine is a chemical that is released from mast cells when allergens are present, and
their effects on the body produce the signs and symptoms of allergy. Steroids, such as
beclometasone dipropionate (Beconase), can also be found as nasal sprays, and these work by
stopping the production of chemicals known as leukotrienes and prostraglandins, which can
contribute to the symptoms of allergy. Leukotriene antagonists, such as montelukast and zafirlukast,
act against leukotrienes. They have fewer side effects than steroids, but are also less effective.

Eye symptoms can be treated using eye drops. As with nasal sprays, there are a few different types
of eye drop. You may be able to find hydrating eye drops, which can relieve symptoms but should
not be used too regularly, as you can get a rebound reaction where your eyes become more dry and
irritated than they were before you started using the eye drops. Antihistamine eye drops, such as
cetirizine hydrochloride, are effective within 10 - 15 minutes. Sodium cromoglicate and nedocromil
can act on mast cells (the cells involved with allergy) and can stop them releasing histamine. You
should not wear contact lenses when using eye drops.

Asthma-like symptoms can be relieved by inhalers, however, inhalers are only given out by
prescription. You can see your doctor if you need to obtain an inhaler.

Animal & pet allergy: There are treatments available focused on common pet allergies. These treatments will not make the allergy disappear, but will help you get rid of the symptoms that can make life so unpleasant for
people suffering from symptoms of pet allergy. What treatments are available?

Antihistamine tablets or syrup: Antihistamine blocks the actions of histamine in the body, and erases allergic reactions. This medication based on antihistamine is mostly recommended for people suffering from hay fever-like symptom such as a runny nose, a blocked nose and itchy eyes.

Nasal spray or nasal drops containing antihistamines or other beneficiary medication, are used to
help reduce nasal congestion and irritation of the tissue and skin of the nose.

Eye Drops: Drops containing sodium or antihistamine help make the eyes feel less itchy and irritated and
reduce eye inflammation.

Mold allergy: Medications for mold treatment is similar to that of other pollen or inhalant allergies, with the main goal of treating the symptoms.

For asthma, inhaled Corticosteroids or Bronchodilators are generally prescribed. This control and
relieve the asthma symptoms and avoid its further progression.

Immunotherapy: To strengthen the immune system, a series of injections with increase dosing that consists of extracts of various allergens are administered to develop tolerance against that allergen.

Contact dermatitis: Wash your hands or parts of the body exposed to the offending material with soap and cool water. Calamine lotion and cool oatmeal bath can help with persistent rash or blister. Oral antihistamine
will relieve itching. Avoid scratching. Topical cortisone cream will also reduce persistent rash.

If rash or blister does not improve or even continue to spread, you should consult your family
doctor or better still see an allergy specialist (allergologist).

Drug allergy: Drug allergy treatment generally involves stopping the medication. You may also need medications to ease symptoms or, in the case of a serious reaction.

- Minor reactions such as rashes or hives may improve with an over-the-counter
antihistamines. Call your doctor before using over-the-counter medications to make sure
you're getting the treatment you need.

- Serious reactions may require treatment with oral or injected corticosteroids at the hospital.
Seek emergency treatment if you have severe rashes or hives, swelling, shortness of breath,
dizziness, or other signs or symptoms of a severe reaction.

Anaphylaxis is a medical emergency requiring an immediate epinephrine injection (EpiPen)
and hospital care to maintain blood pressure and support breathing.

Desensitization: In some cases, sensitivity to a drug can be reduced by starting with a tiny dose and gradually increasing it over time. This can take from one to 10 days and is generally done with medical
supervision at a doctor's office, hospital or allergy clinic. In general, this is done only when you're
allergic to a drug and a satisfactory alternative isn't available. (See Immunotherapy above).

Food allergy: Some people outgrow their food allergies, especially children. However, this is unlikely with
allergies to nuts and fish.

Symptoms of mild food allergies, such as a rash or runny nose, may be treated with antihistamines.
However, it's important that you only take medicines for your allergy on the advice of your doctor.
Always read the patient information leaflet that comes with your medicine and if you have any
questions, ask your pharmacist for advice.

People with severe food allergies who are at risk of anaphylaxis need to take certain precautions.
Despite reading menus and ingredients lists carefully, it's easy to eat a problem food by accident.
Even a tiny amount of a problem food can trigger a severe reaction.

- Make sure that your doctor teaches you how to cope if you have an allergic reaction.

- Wear a bracelet or carry a card that gives details about your allergy.

- Carry a pre-loaded adrenaline syringe (e.g., EpiPen). You must know how to use it in case
   you have an anaphylactic reaction. Check regularly to make sure that it's in full working
   order and within its expiry date. If you use this, you must always seek medical attention
   immediately afterwards.

 - Let your family, friends and work colleagues know of your allergy, and how they can help in
an emergency.

- If your child has a severe allergy, you must make sure that all their carers and teachers have
the knowledge and ability to react correctly in an emergency.

 

Prevention

The ultimate goal of allergy treatment is preventing the symptoms from occurring in the first place.
This usually includes learning how to avoid the allergen, whether it be pets, foods, insects or even
certain chemicals.

Pollen allergy: Here are some tips to minimize pollen exposure:

- Keep windows closed prevent pollens from drifting into your home

- Minimize early morning activity when pollen is usually emitted-between 5-10 a.m.

- Keep your car windows closed when traveling.

- Stay indoors when the pollen count is reported to be high, and on windy days when pollen
   may be present in higher amounts in the air

- Take a vacation during the height of the pollen season to a more pollen-free area, such as the
beach or sea.

- Avoid mowing the lawn and freshly cut grass.

- Machine dry bedding and clothing. Pollen may collect in laundry if it is hung outside to dry.

Dust mite allergy: People with allergy to dust mites notice late night and early morning allergic rhinitis symptoms, after inhaling the dust mite particles over several hours. Since dust mites live year-round, the
allergy is not typically a seasonal problem.

Avoidance of dust mites includes frequent washing of bedding, in hot water (preferable 130 º F)
every week. Other bedding materials such as blankets and comforters should be washed once to
twice a month. Decorative pillows and stuffed animals also harbor dust mites, and should be
washed frequently or removed from the bed. If the pillow or stuffed toy cannot be submersed in
water, these should be placed in the freezer for 24 to 48 hours, and then hand-washed in soapy
water (it is not the cold that kills the dust mites, but the dryness of the freezer).

Encasing pillows and mattresses in dust mite allergen covers is another important avoidance
measure to take. These covers, available at many retailers that offer bedding materials, are
impermeable to dust mites, and trap the mites in the pillow and mattress away from the person. The
covers are placed over the pillow and mattress, and the bedding is placed other the covers.

Cockroaches are typically present in the kitchen, bathrooms and garage, where food and water
sources are available. Removing garbage from the kitchen, keeping pet food in sealed containers,
frequent cleaning of counters and kitchen floors, and using bait traps (such as Combat®) in cabinets
and behind refrigerators can be helpful in eliminating cockroaches.

Dust mites and cockroaches both thrive in humid climates, and efforts to de-humidify (with the use
of a de-humidifier and fixing water leaks), as well as following the recommendations outlined
above, can be successful in reducing the amounts of these allergens in the home.

Pet allergy: For people with cat allergy, avoidance of cats is the mainstay of therapy.

Dog owners may not want to part with their pets, despite the symptoms they endure. Short of
getting rid of the dog, here are some ways to decrease dog allergen exposure for dog owners:

- Ensure the dog is neutered

- Bathing the dog at least once or twice a week

- Wiping the dog with a wet cloth or hand towel daily

- Remove the dog from the bedroom, close the bedroom door and air vents to the bedroom

- Keep the dog outside or in the garage, or in a part of the home with an uncarpeted floor

- Vacuum frequently with a HEPA-equipped vacuum cleaner (HEPA is an acronym for high
   efficiency particulate air which can filter out very small particles).

- Purchase a HEPA room air cleaner for use in the bedroom and/or other parts of the home (it
   is best to keep the HEPA filter off of the floor so as to not stir up more dust)

- Follow house dust mite avoidance precautions

- If the above measures do not help to reduce allergic symptoms, getting rid of the pet dogs
  may be needed, particularly for people with uncontrolled asthma.

- Dog allergen may persist for months to years in the home even after the dog is gone –
  therefore it is important to clean thoroughly
        ◦ steam clean all carpets and upholstered furniture        ◦ launder or dry clean all bedding and curtains

        ◦ vacuum all hard floors

        ◦ wipe down all hard surfaces and furniture

        ◦ replace any air conditioner and heater vent filters

Mold allergy:

- Prevent outdoor molds from entering the home by keeping doors and windows closed and
  using air conditioning equipped with allergen-grade air filters

- Control indoor moisture with the use of dehumidifiers

- Fix water leaks in bathrooms, kitchens and basements

-Ensure adequate ventilation of moist areas

-Clean (or replace) contaminated surfaces with diluted a chlorine bleach solution (one part
  household bleach in 9 parts water), while using proper protective gear (mask and goggles)

- Use HEPA-filters on vacuums or as a stand-alone air filter

- Limit indoor houseplants, and ensure those that are present are free of mold on leaves and in
  potting soil

Drug allergy: If you have a history of a possible drug allergy, a skin test may help find out for certain. Tests for penicillin allergy are generally more reliable than are skin tests for allergies to other drugs.

Once you know you have a drug allergy, you'll need to avoid that drug and related drugs. Tell all of
your health care providers, including your dentist, about your drug allergy. In case you're in an
accident, you may want to wear a medical alert ID bracelet so that emergency workers will know
about your allergy.

You can help avoid future allergic reactions by knowing which medicines you are taking.

- Keep a list of all the medicines you take, including supplements and OTC (Over the
  counter) medicines without prescription. Share this list with your doctor. This will help him
  or her identify other medicine you may be allergic to.

- Whenever you start a new medicine, ask your doctor if it may cause an allergy. This
  includes asking about supplements and over-the-counter medicines. You may have to take
  the medicine for the first time in your doctor's office.

- Do not use someone else's medicine or share yours. A medicine may appear the same but
  have a part that can cause a reaction.

Contact allergy (dermatitis): Preventing contact dermatitis means avoiding contact with those substances such as poison ivy or harsh soaps that may cause it. Prevention strategies include:

- Rinse your skin with water and use a mild soap if you come in contact with a substance you are
  allergic to. Prompt washing can remove many of the irritants or allergens from your skin.
  Be sure to rinse the soap completely off your body.

- Wear cotton or plastic gloves when doing housework to avoid contact with cleaners or solutions.

- If on the job, wear protective clothing or gloves to shield your skin against harmful agents.

- Apply a barrier cream or gel to your skin to provide a protective layer. Also, use a moisturizer to
  restore the outermost layer of skin and to prevent the evaporation of moisture.

- Use a mild, unscented laundry detergent when washing clothes, towels and bedding. Try using
  the extra rinse cycle on your washing machine.

Although contact allergy cannot always be prevented, there are some things that you can do to help
prevent it from occurring. Following are some suggestions for preventing contact dermatitis:

- Wash new clothing and bed linens several times before using them. Contact dermatitis
  caused by clothing is usually due to formaldehyde released by chemicals in the finishing of
  fabrics, and is sometimes due to the dyes. Avoid polyester blends and cottons that are
  labeled "permanent press" and "wrinkle-resistant," and stick to natural fibers, such as cotton,
  linen, and silk. (Though wool is a natural fiber, it can be irritating.)

- Use soaps or detergents specifically formulated for babies' wash if laundry products are
  under suspicion. Avoid fabric softeners and antistatic products, and double-rinse the wash.

- Read the labels on cosmetics. If a cosmetic causes a problem, note the ingredients --
  fragrances and preservatives are the most likely suspects -- and avoid similar cosmetic
  formulations in the future. (Specific fragrance components are not listed, so a switch to
  fragrance-free products should be tried if dermatitis persists).

- Wear heavy-duty vinyl gloves with cotton liners, if possible, when hands are in contact with
  harsh cleansers at home or chemical irritants at work. Avoid abrasive soaps for removing
  grease and oil. Remove rings when using soaps and detergents, because these materials can 
  become trapped under rings and cause irritation. Keep the hands well-moisturized with a
  bland cream or lotion.

It bots well to remember that latex articles especially gloves often contain a generous amount of
Talcum powder to make putting them on easier and the talcum powder is attached to the latex
protein to making the allergen airborne. These particles could then go into the nasal and bronchial
mucous membrane to cause allergic reactions for those who are allergic to latex.

Food allergy: The only treatment for food allergy is not to eat the problem food. A registered dietitian can help you identify and remove a problem food from your diet and replace it with alternatives, to make
sure you don't miss out on essential nutrients. Your dietitian can also explain what you need to look
for on food labels and when eating out.

 
Pathophysiology

All Type l hypersensitivity follow the same mechanism:

Allergen cause IgE (antibody) to be produced by a certain type of immune cell - plasma cells. At the
first exposure to this particular allergen, this reaction (the production of IgE) does not cause the
allergic symptoms.

But on the second exposure of these cells to the allergen also known as the antigen. antibodies
known as IgE will be produced and they (IgE) are found sitting on the surface of the mast cells
and basophils - 2 types of immune cells.

The allergen fits onto the antibody like a key on lock. This key-lock combination releases from the
mast cells and the basophils many different chemical mediators and one of the most prominent and
important is known as HISTAMINE which is responsible for the bulk of the allergic symptoms.

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FIGURE 1

FIGURE 2

 

The cellular level: The allergens get taken into the plasma cells (a type of immune cell) where the
antibody specific to the allergen is produced. At the second or subsequent exposure (in an allergic
sufferer) to the same allergen will result in the production of large quantities of the antibody IgE
and are selectively docked on the surface of the mast cells and the basophils (both belonging to the
immune cells family).

The cellular-tissues-organ level: Upon docking on the surfaces of the mast cells and the basophils,
the antibody-immune cells, i.e., IgE-mast cells and IgE-basophils, make a bee line for the allergen.
The antibody and the allergen make a perfect fit like a lock-key combination and cause the
immediate release of chemical mediators from the mast cells and the basophils into the surrounding
tissues and organs, eliciting symptoms, depending on which part of the body is involved.
For example, if the airborne allergens settles on the mucus of the nose and the airways, mast cells
and basophils will release the chemical mediators to evoke itchy nose and throat. In addition, the
passages to the lungs will be constricted making breathing more difficult.

In a very severe allergic reaction, there is a whole body reaction involving many tissues and organs.
Under these circumstances, the bronchi (airways) will be severely constricted making breathing
difficult or impossible. The generalized dilation of the blood vessels cauase an acute in the fall of the blood
pressure which in itself could be fatal. At least as important is the leakage of fluids from the blood
vessels into the surrounding tissues and when this happens in the lungs the results will be
catastrophic - death.

 

Closing Remarks

Allergy is not just a little bit of itchy nose and eyes but can be fatal. Make sure you know as much
as you can what you are allergic to and take the necessary precautions. You life may dependent
on it.

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