Allergy Terminology : Acute Rhinitis - Inflammation of the nose that occurs for only a few days. Typically this is caused by a virus ("a cold"); if it goes on beyond a week then it is probably bacterial. Allergens - Normally harmless substances which cause an exaggerated allergic reaction (inflammatory response) in sensitive people. Allergic Rhinitis - Medical term for hay fever, a condition due to allergy that mimics a chronic cold. (Hay fever is a misnomer since hay is not a usual cause of this problem and there is no fever. Many substances cause the allergic symptoms in hay fever. Allergic rhinitis is the correct term for this allergic reaction. (Rhinitis means "irritation of the nose" and is a derivative of Rhino, meaning "nose.") Symptoms include nasal congestion, a clear runny nose, sneezing, nose and eye itching, and tearing eyes. Post-nasal dripping of clear mucus frequently causes a cough. Loss of smell is common and loss of taste occurs occasionally. Nose bleeding may occur if the condition is severe. Eye itching, redness, and tearing frequently accompany the nasal symptoms. Chronic Rhinitis - inflammation of the nose that goes on for weeks to months which is different from "a cold", and may be caused by allergy, nasal irritants, structural, or physiological problems. Hay Fever - A seasonal allergy to airborne particles characterized by runny/itchy nose and eyes, sneezing, itchy throat, excess mucus, and nasal congestion. It is a misnomer because it is not caused by hay and it does not produce a fever. Non-Allergic Rhinitis - Inflammatory condition of the nose without an obvious allergy cause. Post Nasal Drip - Mucous accumulation in the back of the nose and throat leading to or giving the sensation of mucus dripping downward from the back of the nose. Summer Cold - Similar to hay fever. Also a misnomer because it is not caused by a virus. Vasomotor Rhinitis - Similar to non-allergic rhinitis, thought to be mediated by an abnormal neuronal control of the blood vessels supplying the nose.

In 1819, an English physician, John Bostock, first described hay fever by detailing his own seasonal nasal symptoms, which he called "summer catarrh." The condition was called hay fever because it was thought to be caused by "new hay." Asthma - Asthma is a breathing problem that results from the inflammation and spasm of the lung's air passages (bronchial tubes). The inflammation causes a narrowing of the air passages, which limits the flow of air into and out of the lungs. Asthma is most often, but not always, related to allergies. Common symptoms include: Shortness of breath Wheezing Coughing Chest tightness Allergic Eyes. Allergic Eyes - (Allergic Conjunctivitis) is inflammation of the tissue layers (membranes) that cover the surface of the eyeball and the undersurface of the eyelid. The inflammation occurs a result of an allergic reaction and may produce the following symptoms: Redness under the lids and of the eye overall Watery, itchy eyes Swelling of the membranes. Allergic Eczema - Allergic Eczema (Atopic Dermatitis) is an allergic rash that is usually not caused by skin contact with an allergen. This condition is commonly associated with allergic rhinitis or asthma and features the following symptoms: Itching, redness, and or dryness of the skin Rash on the face, especially children Rash around the eyes, in the elbow creases, and behind the knees, especially in adults. Hives - Hives (Urticaria) are skin reactions that appear as itchy swellings and can occur on any part of the body. Hives can be caused by an allergic reaction, such as to a food or medication, but they also may occur in non-allergic people. Typical hive symptoms are: Raised red welts Intense itching Allergic Shock - Allergic Shock (Anaphylaxis or Anaphylactic Shock) is a life-threatening allergic reaction that can affect a number of organs at the same time. This response typically occurs when the allergen is eaten (for example, foods) or injected (for example, a bee sting). Some or all of the following symptoms may occur: Hives or reddish discoloration of the skin Nasal congestion Swelling of the throat Stomach pain, nausea, vomiting Shortness of breath, wheezing Low blood pressure or shock. Shock refers to the insufficient circulation of blood to the body's tissues. Shock is most commonly caused by blood loss or an infection. Allergic shock is caused by dilated and "leaky" blood vessels, which result in a drop in blood pressure.

IgE is an antibody that all of us have in small amounts. Allergic persons, however, produce IgE in large quantities. Normally, this antibody is important in protecting us from parasites, but not allergens. During the sensitization period, IgE is being overproduced and coats certain potentially explosive cells that contain chemicals. These cells are capable of causing an allergic reaction on subsequent exposures to the dander. This is because the reaction of the cat dander with the dander IgE irritates the cells and leads to the release of various chemicals, including histamine. These chemicals, in turn, cause inflammation and the typical allergic symptoms. This is how the immune system becomes misguided and primed to cause an allergic reaction when stimulated by an allergen.

An allergy refers to a misguided reaction by our immune system in response to bodily contact with certain foreign substances. It is misguided because these foreign substances are usually harmless and remain so to non- allergic people. Allergy-producing substances are called "allergens." Examples of allergens include pollens, dust mite, molds, danders, and foods. To understand the language of allergy it is important to remember that allergens are substances that are foreign to the body and can cause an allergic reaction in certain people. When an allergen comes in contact with the body, it causes the immune system to develop an allergic reaction in persons who are allergic to it. When you inappropriately react to allergens that are normally harmless to other people, you are having an allergic reaction and can be referred to as allergic or atopic. Therefore, people who are prone to allergies are said to be allergic or "atopic." Austrian pediatrician Clemens Pirquet (1874-1929) first used the term allergy. He referred to both immunity that was beneficial and to the harmful hypersensitivity as "allergy." The word allergy is derived from the Greek words "allos," meaning different or changed and "ergos," meaning work or action. Allergy roughly refers to an "altered reaction." The word allergy was first used in 1905 to describe the adverse reactions of children who were given repeated shots of horse serum to fight infection. The following year, the term allergy was proposed to explain this unexpected "changed reactivity."