Allergies
An allergy is an immune system response to a foreign
substance that’s not typically harmful to your body. These
foreign substances are called allergens. They can include
certain foods, pollen, or pet dander.
Your immune system’s job is to keep you healthy by fighting
harmful pathogens. It does this by attacking anything it thinks
could put your body in danger. Depending on the allergen, this
response may involve inflammation, sneezing, or a host of
other symptoms.
Your immune system normally adjusts to your environment. For
example, when your body encounters something like pet
dander, it should realize it’s harmless. In people with dander
allergies, the immune system perceives it as an outside invader
threatening the body and attacks it.
Allergies are common. Several treatments can help you avoid symptoms.
Allergens
An allergen is a usually harmless substance capable of triggering a response that starts in the immune system and results in an allergic reaction.
For instance, if you have an allergy to pollen, your immune system identifies pollen as an invader or allergen. The immune system responds by releasing chemicals that typically cause symptoms in the nose, throat, eyes, ears, skin or roof of the mouth.
In addition to pollen, other common allergens include dust mites, animal dander, mould, medications, insect venoms and various
foods.
Allergic reactions
Some people sneeze like crazy. Others get itchy hives or watery eyes. But whatever the reaction, it boils down to one thing: allergies.
Learning why these reactions happen can help you keep things under control and feel better.
Why Allergic Reactions Happen
Your immune system has an important job: to defend your body from invaders such as bacteria and viruses that mean you harm.
But when it makes war on substances it shouldn’t, that’s an allergy.
Peanuts, eggs, or pollen, for example, can trigger reactions. They are called allergens.
During a reaction, your immune system releases antibodies. These are proteins that deliver a message to cells: Stop that substance! The cells then send out histamine, which causes blood vessels to expand, and other chemicals, and these trigger the allergy symptoms.
These antibodies are singled-minded. Each one targets only one type of allergen. That explains why someone might be allergic to peanuts but not to eggs.
You can come into contact with allergens in many ways: through the skin, eyes, nose, mouth, or stomach. This can cause your sinuses to clog up, inflame your skin, make it harder to breathe, or cause stomach problems.
What Things Most Often Cause an Attack?
Why do some people have such bad allergies and others don’t? Experts don’t have all the answers, but they say family history is important.
Some common allergens include:
Animal dander Bee stings Certain medications such as penicillin Dust mites Foods -- particularly peanuts, tree nuts, fish,
shellfish, eggs, milk, wheat, and soy
Insect bites Latex or other materials you touch Mould Plants and pollens
The Symptoms, From Itchy Eyes to Sneezing
Your allergy attacks might range from mild and annoying to more severe and even life-threatening. It all depends on the way your body reacts and how much of the allergen got into your system.
If the allergy is severe, the person may have a serious reaction called anaphylaxis. Some cases could be life-threatening and need urgent attention.
Here are some common types of allergies:
Hay fever: Also known as allergic rhinitis, it can cause:
Sneezing Runny or stuffy nose Itchy eyes, nose or roof of mouth Red, swollen, watery eyes -- a condition known
as allergic conjunctivitis
Food allergies: You may feel tingling in your mouth. Your tongue, lips, throat, or face might swell up. Or you could get hives. In the worst cases, you might have anaphylaxis and will need medical help right away.
Eczema: Also known as atopic dermatitis, it is a skin
condition. Most types of eczema are not allergies. But the disease can flare up when you're around things that cause an allergic reaction. Your body's immune system overreacts to substances, called allergens that are usually not harmful. You might get hives, itching,
swelling, sneezing, and a runny nose. You might have it if you have itching, redness, and peeling or flaking.
Medications: If you’re allergic to a certain drug, you may get a rash, facial swelling, or hives. You could find yourself wheezing. In severe cases, you may develop anaphylaxis.
Stings: If you’re allergic to bees or other insects you may get:
A large area of swelling, known as edema, at the site of the sting
Itching or hives all over your body Shortness of breath, wheezing, chest tightness, or
a cough
As with some other allergies, such as food and medication, a severe reaction to a sting can lead to anaphylaxis.
Anaphylaxis: What Is It and How to Get Help
Most people with allergies get only mild to moderate symptoms, but bad cases can lead to anaphylaxis.
It’s a serious situation and can put your body into shock. Food, medications, insect bites, or latex are the most
likely causes.
A second anaphylactic episode can happen up to 12 hours after the first one.
The symptoms of anaphylaxis can come on suddenly.
They can quickly go from a mild rash or runny nose to serious problems such as a hard time breathing, tightness in the throat, hives or swelling, nausea or vomiting, and fainting or dizziness. Some people can get a rapid pulse or their heart will stop beating.
Treatment:
You can find treatment options for mild to moderate allergic reactions. Antihistamines and decongestants can help treat certain symptoms, as can nasal sprays.
If you have an allergic-type asthma, your doctor might also prescribe an inhaler to ease attacks. Or she may inject a special antibody to manage symptoms.
If you don’t get enough relief by avoiding your allergens and using medications, your doctor may want to give you allergy shots. This type of treatment is called
immunotherapy, and it can be effective for hay fever and allergic asthma.
Another type of immunotherapy involves tablets that dissolve under your tongue.
For your sinuses, an over-the-counter medication might ease your symptoms.
Complications of allergies
While you may think of allergies as those pesky sniffles and sneezes that
come around every new season, some of these allergic reactions can
actually be life-threatening.
Anaphylaxis, for example, is a serious reaction to the exposure of
allergens. Most people associate anaphylaxis with food, but any allergen
can cause the signs:
suddenly narrowed airways
increased heart rate
possible swelling of the tongue and mouth
Allergy symptoms can create many complications. Your doctor can help
determine the cause of your symptoms as well as the difference between a
sensitivity and a full-blown allergy. Your doctor can also teach you how to
manage your allergy symptoms so that you can avoid the worst
complications.
Asthma and allergies
Asthma is a common respiratory condition. It makes breathing more difficult
and can narrow the air passageways in your lungs.
Asthma is closely related to allergies. Indeed, allergies can make existing
asthma worse. It can also trigger asthma in a person who’s never had the
condition.
When these conditions occur together, it’s a condition called allergy-
induced asthma, or allergic asthma. Allergic asthma affects about 60
percent of people who have asthma in the United States, estimates the
Allergy and Asthma Foundation of America.
Types of allergies
1. Perennial Allergens
Perennial (or year-round) allergies may be less intense than pollen-based or seasonal allergies. These are most often seen indoors and
include dust mites, cockroaches, moulds and pets. Pets and moulds
can cause a quicker and more obvious response with itching, sneezing, and nasal congestion. But dust mites and cockroaches cause
more of a general feeling of nasal fullness, congestion and eye
irritation. Asthma can also be triggered by the dust mite and cockroach allergen, which is not always as obvious as a cat or dog allergy.
E.g. for perennial allergies: food allergies
Food allergies can trigger swelling, hives, nausea, fatigue, and more. It
may take a while for a person to realize that they have a food allergy. If you
have a serious reaction after a meal and you’re not sure why, see a
medical professional immediately.
2. Seasonal allergies
Hay fever (caused due to pollen grains) symptoms can mimic those of a
cold. They include congestion, runny nose, and swollen eyes. Most of the
time, you can manage these symptoms at home using over-the-counter
treatments.
Allergies on skin
Skin allergies may be a sign or symptom of an allergy. They may also be
the direct result of exposure to an allergen.
For example, eating a food you’re allergic to can cause several symptoms.
You may experience tingling in your mouth and throat. You may also
develop a rash.
Contact dermatitis, however, is the result of your skin coming into direct
contact with an allergen. This could happen if you touch something you’re
allergic to, such as a cleaning product or plant.
Types of skin allergies include:
Rashes. Areas of skin are irritated, red, or swollen, and can be
painful or itchy.
Eczema. Patches of skin become inflamed and can itch and bleed.
Contact dermatitis. Red, itchy patches of skin develop almost
immediately after contact with an allergen.
Sore throat. Pharynx or throat is irritated or inflamed.
Hives. Red, itchy, and raised welts of various sizes and shapes
develop on the surface of the skin.
Swollen eyes. Eyes may be watery or itchy and look “puffy.”
Itching. There’s irritation or inflammation in the skin.
Burning. Skin inflammation leads to discomfort and stinging
sensations on the skin.
Allergy treatments
The best way to avoid allergies is to stay away from whatever triggers the
reaction. If that’s not possible, there are treatment options available.
Medication
Allergy treatment often includes medications like antihistamines to control
symptoms. The medication can be over the counter or prescription. What
your doctor recommends depends on the severity of your allergies.
Allergy medications include:
antihistamines like diphenhydramine (Benadryl)
corticosteroids
cetirizine (Zyrtec)
Immunotherapy
Many people opt for immunotherapy. This involves several injections over
the course of a few years to help the body get used to your allergy.
Successful immunotherapy can prevent allergy symptoms from returning.
Emergency epinephrine
If the person has a severe, life-threatening allergy, they need to carry an
emergency epinephrine shot. The shot counters allergic reactions until
medical help arrives.
How allergies are diagnosed
The doctor can diagnose allergies in several ways:
First, the doctor will ask about your symptoms and perform a physical
exam. They’ll ask about anything unusual you may have eaten recently and
any substances you may have come in contact with. For example, if you
have a rash on your hands, your doctor may ask if you put on latex gloves
recently.
Lastly, a blood test and skin test can confirm or diagnose allergens your
doctor suspects you have.
Allergy blood test
Your doctor may order a blood test. Your blood will be tested for the
presence of allergy-causing antibodies called immunoglobulin E (IgE).
These are cells that react to allergens. Your doctor will use a blood test to
confirm a diagnosis if they’re worried about the potential for a severe
allergic reaction.
Skin test
Your doctor may also refer you to an allergist for testing and treatment. A
skin test is a common type of allergy test carried out by an allergist.
During this test, your skin is pricked or scratched with small needles
containing potential allergens. Your skin’s reaction is documented. If you’re
allergic to a particular substance, your skin will become red and inflamed.
Preventing symptoms
There’s no way to prevent allergies. But there are ways to prevent the
symptoms from occurring. The best way to prevent allergy symptoms is to
avoid the allergens that trigger them.
Avoidance is the most effective way to prevent food allergy symptoms. An
elimination diet can help you determine the cause of your allergies so you
know how to avoid them. To help you avoid food allergens, thoroughly read
food labels and ask questions while dining out.
Preventing seasonal, contact, and other allergies comes down to knowing
where the allergens are located and how to avoid them. If you’re allergic to
dust, for example, you can help reduce symptoms by installing proper air
filters in your home, getting your air ducts professionally cleaned, and
dusting your home regularly.
Proper allergy testing can help you pinpoint your exact triggers, which
makes them easier to avoid. These other tips can also help you avoid
dangerous allergic reactions.
https://www.youtube.com/watch?v=hmb066Vzdek
WORK SHEET
FILL IN THE BLANKS
1. __________ is a serious life threatening reaction.
2. The basic medications for allergies are ________.
3. Antibodies cause certain cells in the body to release __________ which
causes the symptoms of allergic reactions.
4. The substances that can trigger an immune response are called
_________.
5. __________ allergies rise with the change in the season.
CHOOSE THE BEST.
1. Allergy is an example of
a) Communicable disease
b) Non communicable disease
c) None of the above
2. Food allergy is a type of __________.
a) Perennial allergy
b) Seasonal allergy
c) Both
3. Chemicals that immune cells release are called
a) Histamine
b) Anti histamine
c) Fluids
4. Pollens, animal fur and house dust are examples of
a) Air borne allergens
b) Drug allergens
c) Food allergens
5. Asthma affects the __________.
a) Skin
b) Lungs
c) Heart
6. Allergic reaction mark by red, raised areas of the skin.
a) Hives
b) Nausea
c) Cramps
CORRECT THE FALSE STATEMENTS.
1. Allergy is the reaction of hyposensitivity of the body tissues to certain
substances.
2. Perennial allergy is caused during certain seasons.
3. Histamines are the basic medication provided for allergies.
4. Substances that trigger an allergy are called allergic reactions.
5. Asthma is a serious, life threatening allergic reaction.
WORK SHEET ANSWERS.
Fill ups
1. Anaphylaxis
2. Anti-histamine
3. Histamine
4. Antigens
5. Seasonal
Choose the best
1. Non communicable disease.
2. Perennial allergy
3. Histamine
4. Air borne allergens
5. Lungs
6. Hives
CORRECT THE FALSE STATEMENT
1. Allergy is the reaction of hypersensitivity of the body tissues to certain
substances.
2. Seasonal allergy is caused during certain seasons.
3. Anti-histamines are the basic medication provided for allergies.
4. Substances that trigger an allergy are called allergens.
5. Anaphylaxis is a serious, life threatening allergic reaction.
Text book short Question and Answers.
1. Name the five most common allergens.
Ans: Pollen grain, animal fur, strong sunlight, house dust, certain food
items.
2. What are the two major types of allergies?
Ans: Perennial allergy
This allergy may occur any time of the year. Unrelated to the season and
may last all year round. Example: food allergy.
Seasonal allergy
The allergy that occur during certain seasons of the year are called as
seasonal allergy. Example: hay fever.
3. What is the inexpensive way to avoid allergen?
Ans: The most certain treatment for allergies is to avoid the substances that
trigger them and strictly follow the preventive measures to avoid allergens.
4. (Omit)
5. What are the precautions taken against dust and pollen allergies?
Ans:
To avoid dust allergies, we must keep the house dust free and clean.
And wear a mask if we go outside.
To avoid pollen allergies immunotherapy (allergy shots) can be taken
or decrease exposure to the pollen grains by wearing a mask.
6. What is Anaphylaxis?
Ans: Anaphylaxis is a severe life threatening reaction to certain allergens.
The body tissues may swell including tissues in the throat and there is a
sudden drop in the blood pressure.
7. (omit)