An ALLERGY is a damaging immune response by the body to a substance, especially pollen, fur, a particular food, or dust, to which it has become hypersensitive. And as I sat do to a family meal with friends and family the other day. I began to learn it’s not just about nut allergies and items. It is not always about the flowers or season it is HUMAN reaction to physical property. Your allergy symptoms are set off by your immune system reacting to a substance that is harmless to other people. This substance, the allergen, is what your body finds foreign, like an invader. Your body mounts a protective response by releasing chemical called histamine into your bloodstream that goes to the site of the invasion. This release of histamine, part of your body’s defense against the pesky intruders, is the cause of your most common allergy symptoms.
Ignoring this FIRST AID item can result in some people deaths so it is an important workplace safety issue. Allergies are a major cause of illness in the United States. As many as 50 million people – about one in five – have allergies. And did you know that more than 300,000 children in Canada have food allergies?
T cells play an important role in the pathophysiology of allergic reactions (see Pathophysiology). In addition, the term immediate hypersensitivity is somewhat of a misnomer because it does not account for the late-phase reaction or for the chronic allergic inflammation that often occurs with these types of reactions.
Allergic reactions manifest clinically as anaphylaxis, allergic asthma, urticaria, angioedema, allergic rhinitis, some types of drug reactions, and atopic dermatitis. These reactions tend to be mediated by IgE, which differentiates them from non-IgE-mediated (formerly called anaphylactoid) reactions that involve IgE-independent mast cell and basophil degranulation. Such reactions can be caused by iodinated radiocontrast dye, opiates, or vancomycin and appear similar clinically to urticaria or even anaphylaxis. Patients prone to IgE-mediated allergic reactions are said to be atopic. Atopy is the genetic predisposition to make IgE antibodies in response to allergen exposure.
4 types and 7 categories in your safety topics:
· Type I reactions (ie, immediate hypersensitivity reactions) involve immunoglobulin E (IgE)–mediated release of histamine and other mediators from mast cells and basophils. ] Examples include anaphylaxis and allergic rhinoconjunctivitis.
· Type II reactions (ie, cytotoxic hypersensitivity reactions) involve immunoglobulin G or immunoglobulin M antibodies bound to cell surface antigens, with subsequent complement fixation. An example is drug-induced hemolytic anemia.
· Type III reactions (ie, immune-complex reactions) involve circulating antigen-antibody immune complexes that deposit in postcapillary venules, with subsequent complement fixation. An example is serum sickness.
· Type IV reactions (ie, delayed hypersensitivity reactions, cell-mediated immunity) are mediated by T cells rather than by antibodies. An example is contact dermatitis from poison ivy or nickel allergy.
This system divides immunopathologic responses into the following 7 categories:
· Inactivation/activation antibody reactions
· Cytotoxic or cytolytic antibody reactions
· Immune-complex reactions
· Allergic reactions
· T-cell cytotoxic reactions
· Delayed hypersensitivity reactions
· Granulomatous reactions
Only 45% of Canadians say they would know what to do if they saw someone having an allergic reaction. The severity of allergies varies from person to person and can range from minor irritation to anaphylaxis — a potentially life-threatening emergency. While most allergies can’t be cured, treatments can help relieve your allergy symptoms.
In Canada, The Food and Drug Regulations require that most pre-packaged foods carry a label and that their ingredients appear in a list in decreasing order of proportion. However, some ingredients used in food products which were previously exempt from declaration in the list of ingredients, (e.g., components of margarine, seasoning and flour) will now be required to appear on food labels also.
Health Canada has worked with the medical community, consumer associations, and the food industry to enhance labelling requirements for priority allergens, gluten sources and sulphite in pre-packaged foods sold in Canada. Proposed new regulations will strengthen labelling requirements by requiring that the most common food and food ingredients which can cause life-threatening or severe allergic reactions are always identified by their common names so that consumers can easily recognize them on food labels.
Common allergens include pollen and certain food. Metals and other substances may also cause problems. Food, insect stings, and medications are common causes of severe reactions. Their development is due to both genetic and environmental factors. The underlying mechanism involves immunoglobulin E antibodies (IgE), part of the body’s immune system, binding to an allergen and then to a receptor on mast cells or basophils where it triggers the release of inflammatory chemicals such as histamine. Diagnosis is typically based on a person’s medical history. Further testing of the skin or blood may be useful in certain cases. Positive tests, however, may not mean there is a significant allergy to the substance in question. Early exposure to potential allergens may be protective. Treatments for allergies include avoiding known allergens and the use of medications such as steroids and antihistamines. In severe reactions injectable adrenaline (epinephrine) is recommended. Allergen immunotherapy, which gradually exposes people to larger and larger amounts of allergen, is useful for some types of allergies such as hay fever and reactions to insect bites. Its use in food allergies is unclear.
Allergies are common. In the developed world, about 20% of people are affected by allergic rhinitis, about 6% of people have at least one food allergy, and about 20% have atopic dermatitis at some point in time. Depending on the country about 1–18% of people have asthma. Anaphylaxis occurs in between 0.05–2% of people. Rates of many allergic diseases appear to be increasing. The word “allergy” was first used by Clemens von Pirquet in 1906
Allergy symptoms occur when your immune system overreacts to something that is harmless to most people but triggers a reaction in anyone sensitive to it. This substance is known as an allergen.
Allergies can be seasonal (worsening during certain times of the year, such as pollen allergies in the spring) or perennial (occurring year-round). Common allergens include weed or grass pollen, dust mites, animal dander, mold, insect stings and a variety of food types, such as eggs, shellfish, nuts and grains. If you come in contact with something to which you are allergic, your immune system considers it dangerous and releases a chemical called histamine to counteract it.
The release of histamine can cause a variety of symptoms, including a skin rash, headache, sneezing, runny nose, swelling, nausea and diarrhea. The most severe reaction, known as anaphylaxis, can be life-threatening.
If the allergen is something you breathe in, your reaction will most likely affect your eyes, nose and lungs. If the allergen is something you consume, you’re more likely to have symptoms in your mouth, stomach and intestines.
Allergy symptoms depend on the substance involved and can affect the airways, sinuses and nasal passages, skin, and digestive system. Allergic reactions can range from mild to severe. In some severe cases, allergies can trigger a life-threatening reaction known as anaphylaxis.
Hay fever, also called allergic rhinitis, may cause:
· Itching of the nose, eyes or roof of the mouth
· Runny, stuffy nose
· Watery, red or swollen eyes (conjunctivitis)
A food allergy may cause:
· Tingling mouth
· Swelling of the lips, tongue, face or throat
An insect sting allergy may cause:
· A large area of swelling (edema) at the sting site
· Itching or hives all over the body
· Cough, chest tightness, wheezing or shortness of breath
A drug allergy may cause:
· Itchy skin
· Facial swelling
Atopic dermatitis, an allergic skin condition also called eczema, may cause skin to:
· Flake or peel
Some types of allergies, including allergies to foods and insect stings, have the potential to trigger a severe reaction known as anaphylaxis. A life-threatening medical emergency, anaphylaxis can cause you to go into shock. Signs and symptoms of anaphylaxis include:
· Loss of consciousness
· A drop in blood pressure
· Severe shortness of breath
· Skin rash
· A rapid, weak pulse
· Nausea and vomiting
When to see a doctor
You might see a doctor if you have symptoms you think may be caused by an allergy, especially if you notice something that seems to trigger your symptoms. If you have symptoms after starting a new medication, call the doctor who prescribed it right away.
For a severe allergic reaction (anaphylaxis), call 911 or your local emergency number or seek emergency medical help. If you carry an epinephrine auto-injector (such as EpiPen, others), give yourself a shot right away.
Even if your symptoms improve after an epinephrine injection, you should go to the emergency department to make sure symptoms don’t return when the effects of the injection wear off.
If you’ve had a severe allergy attack or any signs and symptoms of anaphylaxis in the past, make an appointment to see your doctor. Evaluation, diagnosis and long-term management of anaphylaxis are complicated, so you’ll probably need to see a doctor who specializes in allergies and immunology.
An allergy starts when your immune system mistakes a normally harmless substance for a dangerous invader. The immune system then produces antibodies that remain on the alert for that particular allergen. When you’re exposed to the allergen again, these antibodies can release a number of immune system chemicals, such as histamine, that cause allergy symptoms.
Common allergy triggers include:
· Airborne allergens, such as pollen, animal dander, dust mites and mold
· Certain foods, particularly peanuts, tree nuts, wheat, soy, fish, shellfish, eggs and milk
· Insect stings, such as bee stings or wasp stings
· Medications, particularly penicillin or penicillin-based antibiotics
· Latex or other substances you touch, which can cause allergic skin reactions
You may be at increased risk of developing an allergy if you:
· Have a family history of asthma or allergies. You’re at increased risk of allergies if you have family members with asthma or allergies such as hay fever, hives or eczema.
· Are a child. Children are more likely to develop an allergy than are adults. Children sometimes outgrow allergic conditions as they get older.
· Have asthma or another allergic condition. Having asthma increases your risk of developing an allergy, and vice versa. Also, having one type of allergic condition makes you more likely to be allergic to something else.
Having an allergy increases your risk of certain other medical problems, including:
· Anaphylaxis. If you have severe allergies, you’re at increased risk of this serious allergy-induced reaction. Foods, medications and insect stings are the most common triggers of anaphylaxis.
· Asthma. If you have an allergy, you’re more likely to have asthma — an immune system reaction that affects the airways and breathing. In many cases, asthma is triggered by exposure to an allergen in the environment (allergy-induced asthma).
· Sinusitis and infections of the ears or lungs. Your risk of getting these conditions is higher if you have hay fever or asthma.
· Fungal complications of your sinuses or your lungs. You’re at increased risk of getting these conditions, known as allergic fungal sinusitis and allergic bronchopulmonary aspergillosis, if you have an allergy.
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