Allergic Cascade Glossary of Terms

Common Allergy Triggers Slideshow

Adjacent: Lying nearby. Related terms include superjacent, subjacent, and circumjacent. From ad-, near + the Latin jacere, to lie = to lie near.

Allergen: A substance that is foreign to the body and can cause an allergic reaction in certain people. For examples, pollen, dander, mold.

Allergic reaction: The hypersensitive response of the immune system of an allergic individual to a substance.
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Allergy : A misguided reaction to foreign substances by the immune system , the body system of defense against foreign invaders, particularly pathogens (the agents of infection ). The allergic reaction is misguided in that these foreign substances are usually harmless. The substances that trigger allergy are called allergen. Examples include pollens , dust mite, molds , danders , and certain foods. People prone to allergies are said to be allergic or atopic .
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Allergy shots: See Allergy desensitization.

Anaphylaxis: Allergic reaction. In severe cases, this can include potentially deadly anaphylactic shock.

Antibody: An immunoglobulin, a specialized immune protein , produced because of the introduction of an antigen into the body, and which possesses the remarkable ability to combine with the very antigen that triggered its production.
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Antigen: A substance that is capable of causing the production of an antibody .
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Antihistamines: Drugs that combat the histamine released during an allergic reaction by blocking the action of the histamine on the tissue. Antihistamines do not stop the formation of histamine nor do they stop the conflict between the IgE and antigen. Therefore, antihistamines do not stop the allergic reaction but protect tissues from some of its effects. Antihistamines frequently cause mouth dryness and sleepiness. Newer "non sedating" antihistamines are generally thought to be somewhat less effective. Antihistamine side effects that very occasionally occur include urine retention in males and fast heart rate.

Asthma : A common disorder in which chronic inflammation of the bronchial tubes (bronchi) makes them swell, narrowing the airways. Asthma involves only the bronchial tubes and does not affect the air sacs ( alveoli ) or the lung tissue (the parenchyma of the lung) itself.
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Balance: A biological system that enables us to know where our bodies are in the environment and to maintain a desired position. Normal balance depends on information from the inner ear, other senses (such as sight and touch) and muscle movement.
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Basophil: A type of leukocyte (white blood cell) with coarse bluish-black granules of uniform size within the cytoplasm and typically a bilobate (two-lobed) nucleus. Basophils are so named because their cytoplasmic granules stain with basic dyes. Basophils normally constitute 0.5 to 3% of the peripheral blood leukocytes. Basophils contain (and can release) histamine and serotonin. Also called a basophilic leukocyte.

Blood: The familiar red fluid in the body that contains white and red blood cells, platelets, proteins, and other elements. The blood is transported throughout the body by the circulatory system. Blood functions in two directions: arterial and venous. Arterial blood is the means by which oxygen and nutrients are transported to tissues while venous blood is the means by which carbon dioxide and metabolic by-products are transported to the lungs and kidneys, respectively, for removal from the body.

Blood pressure: The blood pressure is the pressure of the blood within the arteries. It is produced primarily by the contraction of the heart muscle. It's measurement is recorded by two numbers. The first (systolic pressure) is measured after the heart contracts and is highest. The second (diastolic pressure) is measured before the heart contracts and lowest. A blood pressure cuff is used to measure the pressure. Elevation of blood pressure is called "hypertension".

Cascade: A sequence of successive activation reactions involving enzymes (enzyme cascade) or hormones (hormone cascade) characterized by a series of amplifications of an initial stimulus. In blood coagulation, for example, each enzyme activates the next until the final product, the fibrin clot, is reached.

Cell: The basic structural and functional unit in people and all living things. Each cell is a small container of chemicals and water wrapped in a membrane .
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Chronic: This important term in medicine comes from the Greek chronos, time and means lasting a long time.
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Condition: The term "condition" has a number of biomedical meanings including the following:

1. An unhealthy state, such as in "this is a progressive condition."
2. A state of fitness, such as "getting into condition."
3. Something that is essential to the occurrence of something else; essentially a "precondition."
4. As a verb: to cause a change in something so that a response that was previously associated with a certain stimulus becomes associated with another stimulus; to condition a person, as in behavioral conditioning.

Cytotoxic: Toxic to cells, cell-toxic, cell-killing. Any agent or process that kills cells. Chemotherapy and radiotherapy are forms of cytotoxic therapy. They kill cells.
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Dander: Tiny scales shed from human or animal skin or hair. Dander floats in the air, settles on surfaces and makes up much household dust. Cat dander is a classic cause of allergic reactions.

Dilation: The process of enlargement, stretching, or expansion. The word "dilatation" means the same thing. Both come from the Latin "dilatare" meaning "to enlarge or expand."

Disease: Illness or sickness often characterized by typical patient problems (symptoms) and physical findings (signs). Disruption sequence: The events that occur when a fetus that is developing normally is subjected to a destructive agent such as the rubella (German measles) virus.

Environment: The sum of the total of the elements, factors and conditions in the surroundings which may have an impact on the development , action or survival of an organism or group of organisms.
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Essential: 1. Something that cannot be done without.
2. Required in the diet, because the body cannot make it. As in an essential amino acid or an essential fatty acid.
3. Idiopathic. As in essential hypertension. "Essential" is a hallowed term meaning "We don't know the cause."

Family: 1. A group of individuals related by blood or marriage or by a feeling of closeness. 2. A biological classification of related plants or animals that is a division below the order and above the genus. 3. A group of genes related in structure and in function that descended from an ancestral gene. 4. A group of gene products similarly related in structure and function and of shared genetic descent. 5. Parents and their children. The most fundamental social group in humans.

Fever : Although a fever technically is any body temperature above the normal of 98.6 degrees F. (37 degrees C.), in practice a person is usually not considered to have a significant fever until the temperature is above 100.4 degrees F (38 degrees C.).
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Genetic: Having to do with genes and genetic information.

Hay fever: A seasonal allergy to airborne particles characterized by itchy eyes, runny nose, nasal congestion, sneezing, itchy throat, and excess mucus.
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Histamine: Substance that plays a major role in many allergic reactions. Histamine dilates blood vessels and makes the vessel walls abnormally permeable.

Hygiene: The science of preventive medicine and the preservation of health. From the name of Hygeia, the daughter of Asklepios, the Greek god of medicine (whose staff with entwined snake is the symbol of medicine). Asklepios (known to the Romans as Aesculapius) had a number of children including not only Hygeia but also Panaceia, the patroness of clinical medicine. Hygeia also followed her father into medicine. As the patroness of health, Hygeia was charged with providing a healthy environment to prevent illness. In Greek, "hygieia" means health.

Hygiene hypothesis: A hypothesis that states that exposure to allergens in the environment early in life reduces the risk of developing allergies by boosting immune system activity. Conversely, relatively clean environment in early life would sway the immune system towards allergy-promoting responses. Also called the hygiene theory.
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Immune: Protected against infection. The Latin immunis means free, exempt.

Immune response: Any reaction by the immune system.

Immune system: A complex system that is responsible for distinguishing us from everything foreign to us, and for protecting us against infections and foreign substances. The immune system works to seek and kill invaders.
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Immunity: The condition of being immune. Immunity can be innate (for example, humans are innately immune to canine distemper) or conferred by a previous infection or immunization.

Immunotherapy: Treatment to stimulate or restore the ability of the immune (defense) system to fight infection and disease. Biological therapy is thus any form of treatment that uses the body's natural abilities that constitute the immune system to fight infection and disease or to protect the body from some of the side effects of treatment.
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Infection: The growth of a parasitic organism within the body. (A parasitic organism is one that lives on or in another organism and draws its nourishment therefrom.) A person with an infection has another organism (a "germ") growing within him, drawing its nourishment from the person.
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Inflammation: A basic way in which the body reacts to infection , irritation or other injury, the key feature being redness, warmth, swelling and pain . Inflammation is now recognized as a type of nonspecific immune response .
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Injury: Harm or hurt. The term "injury" may be applied in medicine to damage inflicted upon oneself as in a hamstring injury or by an external agent on as in a cold injury. The injury may be accidental or deliberate, as with a needlestick injury. The term "injury" may be synonymous (depending on the context) with a wound or with trauma.

Itching: An uncomfortable sensation in the skin that feels as if something is crawling on the skin or in the skin, and makes the person want to scratch the affected area.
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Leukocytes: Cells that help the body fight infections and other diseases. Also called white blood cells (WBCs).

Leukotriene: One of a group of hormones that cause the symptoms of hayfever and asthma . Derived from arachidonic acid, the leukotrienes act by mediating immediate hypersensitivity. Leukotriene modifiers that prevent the production or action of leukotrienes are used to treat hayfever and asthma.
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Lungs: The lungs are a pair of breathing organs located with the chest which remove carbon dioxide from and bring oxygen to the blood. There is a right and left lung.

Lymphocytes: A small white blood cell ( leukocyte ) that plays a large role in defending the body against disease.
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Mast cell: A connective tissue cell whose normal function is unknown but which is frequently injured in allergic reactions, releasing chemicals including histamine that are very irritating and cause itching, swelling, and fluid leakage from cells. These allergic chemicals may also cause muscle spasm and lead to lung and throat tightening, as in asthma. Also known as a mastocyte or labrocyte.

Medication: 1. A drug or medicine. 2. The administration of a drug or medicine. (Note that "medication" does not have the dangerous double meaning of "drug.")

Mouth: 1. The upper opening of the digestive tract, beginning with the lips and containing the teeth, gums, and tongue. Foodstuffs are broken down mechanically in the mouth by chewing and saliva is added as a lubricant. Saliva contains amylase, an enzyme that digests starch. 2. Any opening or aperture in the body. The mouth in both senses of the word is also called the os, the Latin word for an opening, or mouth. The o in os is pronounced as in hope. The genitive form of os is oris from which comes the word oral.

Mucous: Pertaining to mucus, a thick fluid produced by the lining of some tissues of the body.
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Nasal: Having to do with the nose. Nasal drops are intended for the nose, not (for example) the eyes. The word "nasal" came from the Latin "nasus" meaning the nose or snout.

Nerve: A bundle of fibers that uses chemical and electrical signals to transmit sensory and motor information from one body part to another. See: Nervous system.

Nose: The external midline projection from the face.
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Pollen: Small, light, dry protein particles from trees, grasses, flowers, and weeds that may be spread by the wind. Pollen particles are usually the male sex cells of the plant, and are smaller than the tip of a pin. Pollen is a potent stimulator of allergic responses. It lodges in the mucus membranes that line the nose and in other parts of the respiratory tract, causing irritation and histamine reactions.
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Prostaglandin: One of a number of hormone-like substances that participate in a wide range of body functions such as the contraction and relaxation of smooth muscle, the dilation and constriction of blood vessels, control of blood pressure, and modulation of inflammation. Prostaglandins are derived from a chemical called arachidonic acid.

Proteins: Large molecules composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein.
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Ragweed: Any of a number of weedy composite herbs that produce a pollen that is a frequent cause of allergies. Of all allergy sufferers in the United States, 75% are allergic to ragweed.

Receptor: 1. In cell biology, a structure on the surface of a cell (or inside a cell) that selectively receives and binds a specific substance. There are many receptors. There is a receptor for ( insulin ; there is a receptor for low-density lipoproteins ( LDL ); etc. To take an example, the receptor for substance P, a molecule that acts as a messenger for the sensation of pain , is a unique harbor on the cell surface where substance P docks. Without this receptor, substance P cannot dock and cannot deliver its message of pain. Variant forms of nuclear hormone receptors mediate processes such as cholesterol metabolism and fatty acid production. Some hormone receptors are implicated in diseases such as diabetes and certain types of cancer. A receptor called PXR appears to jump-start the body's response to unfamiliar chemicals and may be involved in drug-drug interactions.
2. In neurology, a terminal of a sensory nerve that receives and responds to stimuli.
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Recurrent: Back again. A recurrent fever is a fever that has returned after an intermission: a recrudescent fever.

Runny nose: Rhinorrhea is the medical term for this common problem. From the Greek words "rhinos" meaning "of the nose" and "rhoia" meaning "a flowing."

Shock: In medicine, shock is a critical condition brought on by a sudden drop in blood flow through the body. There is failure of the circulatory system to maintain adequate blood flow. This sharply curtails the delivery of oxygen and nutrients to vital organs. It also compromises the kidney and so curtails the removal of wastes from the body. Shock can be due to a number of different mechanisms including not enough blood volume (hypovolemic shock) and not enough output of blood by the heart (cardiogenic shock). The signs and symptoms of shock include low blood pressure (hypotension), overbreathing (hyperventilation), a weak rapid pulse, cold clammy grayish-bluish (cyanotic) skin, decreased urine flow (oliguria), and mental changes (a sense of great anxiety and foreboding, confusion and, sometimes, combativeness).
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Skin: The skin is the body's outer covering. It protects us against heat and light, injury, and infection. It regulates body temperature and stores water, fat, and vitamin D. Weighing about 6 pounds, the skin is the body's largest organ. It is made up of two main layers; the outer epidermis and the inner dermis.

T cell: A type of white blood cell that is of key importance to the immune system and is at the core of adaptive immunity, the system that tailors the body's immune response to specific pathogens. The T cells are like soldiers who search out and destroy the targeted invaders.
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Throat: The throat is the anterior (front) portion of the neck beginning at the back of the mouth , consisting anatomically of the pharynx and larynx . The throat contains the trachea and a portion of the esophagus .
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Tissue: A tissue in medicine is not like a piece of tissue paper. It is a broad term that is applied to any group of cells that perform specific functions. A tissue in medicine need not form a layer. Thus,

• The bone marrow is a tissue;
• Connective tissue consists of cells that make up fibers in the framework supporting other body tissues; and
• Lymphoid tissue is the part of the body's immune system that helps protect it from bacteria and other foreign entities.
• Pictures of Common Allergy Triggers - Slideshow

Tubes: The "tubes" are medically known as the Fallopian tubes. There are two Fallopian tubes, one on each side, which transport the egg from the ovary to the uterus (the womb). The Fallopian tubes have small hair-like projections called cilia on the cells of the lining.
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Vessel: A tube in the body that carries fluids: blood vessels or lymph vessels.

Wheal: A raised, itchy (pruritic) area of skin that is almost always an overt sign of allergy .
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Wheezing: A whistling noise in the chest during breathing when the airways are narrowed or compressed.

White blood cell: One of the cells the body makes to help fight infections. There are several types of white blood cells ( leukocytes ). The two most common types are the lymphocytes and neutrophils (also called polymorphonuclear leukocytes, PMNs, or "polys").
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From the Doctors at MedicineNet.com

Allergy - Get the facts about allergic reactions, causes, allergy types (food, dust, mold, seasonal), symptoms and signs (skin rash, itching, red bumps, sneezing). Source:MedicineNet Hay Fever - Read about hay fever (allergic rhinitis), what it is, its causes (pollen), treatment (medicine, allergy injection) and symptoms (sneezing). Source:MedicineNet Anaphylaxis - Read about anaphylaxis (severe allergic reaction) causes (insect stings, latex allergy, food allergy, medication allergy) symptoms, diagnosis, treatment, and prevention. Source:MedicineNet Read 34 more Allergic Cascade related articles ... Worst Cities for Spring Allergies