Insect Bites Glossary of Medical Terms

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These are medical definitions of medical terms from the MedTerms.com medical dictionary that appear in the Insect Bites article.

Airway: The path air follows to get into and out of the lungs. The mouth and nose are the normal entry and exit ports. Entering air then passes through the back of the throat (pharynx), continues through the voice box (larynx), down the trachea, and finally out the branching tubes known as bronchi.
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Airway obstruction: Partial or complete blockage of the breathing tubes to the lungs. Obstruction of the airway can be due to different causes including foreign bodies, allergic reactions, infections, anatomical abnormalities and trauma.
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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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Amebic dysentery: Dysentery (inflammation of the intestine) with ulcers in the colon due to infection with an ameba (Entamoeba histolytica). This single-celled parasite is transmitted to humans via contaminated water and food. Amebic dysentery can be accompanied by amebic infection of the liver and other organs. "Ameba" is from the Greek "amoibe" meaning "change" because amebae constantly change shape. "Dysentery" is composed of the Greek "dys-" meaning "abnormal or painful" + "enteron" meaning "intestine" = abnormal or painful intestine.
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Anaphylactic shock: A widespread and very serious allergic reaction. Symptoms include dizziness , loss of consciousness, labored breathing, swelling of the tongue and breathing tubes, blueness of the skin, low blood pressure , heart failure, and death. Immediate emergency treatment is required for this type of shock , including administration of antivenom in the case of bee or wasp stings.
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Anaphylaxis: Allergic reaction. In severe cases, this can include potentially deadly anaphylactic shock .
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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.
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Bee sting: Stings from bees and other large stinging insects such as yellow jackets, hornets and wasps can trigger allergic reactions varying greatly in severity. Avoidance and prompt treatment are essential. In selected cases, allergy injection therapy is highly effective. (The three "A's" of insect allergy are Adrenaline, Avoidance and Allergist.)
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Brain: That part of the central nervous system that is located within the cranium ( skull ). The brain functions as the primary receiver, organizer and distributor of information for the body. It has two (right and left) halves called "hemispheres."
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Bubonic plague : The most common form of the plague, named for the characteristic buboes -- buboes are enlarged lymph nodes ("swollen glands") -- in the groin which are usually very tender and painful. Lymph nodes may be similarly affected elsewhere such as in the armpits and neck. Common but less specific features of the disease include headache , fever, chills, and weakness.
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Calamine: An astringent made from zinc carbonate or zinc oxide, usually used in lotion form to treat skin problems that cause itching or discomfort.
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Cardiovascular: The circulatory system comprising the heart and blood vessels which carries nutrients and oxygen to the tissues of the body and removes carbon dioxide and other wastes from them.
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Cardiovascular system: The circulatory system which comprises the heart and blood vessels. The system carries nutrients and oxygen to the tissues of the body and removes carbon dioxide and other wastes from them.
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Cellulitis: An acute spreading bacterial infection below the surface of the skin characterized by redness (erythema), warmth, swelling, and pain. Cellulitis can also cause fever, chills, and "swollen glands" (enlarged lymph nodes). Cellulitis is a clinical diagnosis based on the spreading involvement of skin and subcutaneous tissues with erythema, swelling, and local tenderness, accompanied by fever and malaise.
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Chest: The area of the body located between the neck and the abdomen . The chest contains the lungs , the heart and part of the aorta . The walls of the chest are supported by the dorsal vertebrae , the ribs , and the sternum .
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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.

Contrast: Short for "contrast media." Contrast media are X-ray dyes used to provide contrast, for example, between blood vessels and other tissue.
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Cortisone: An adrenocorticoid hormone , a naturally occurring hormone made by and secreted by the adrenal cortex , the outer part (the cortex ) of the adrenal gland .
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Dengue: Also known as Dengue fever , an acute mosquito-borne viral illness of sudden onset that usually follows a benign course with headache , fever , prostration, severe joint and muscle pain , swollen glands (lymphadenopathy) and rash . The presence (the "dengue triad") of fever, rash, and headache (and other pains) is particularly characteristic of dengue. Dengue is endemic throughout the tropics and subtropics. It goes by other names including breakbone or dandy fever. Victims of dengue often have contortions due to the intense joint and muscle pain. Hence, the name "breakbone fever." Slaves in the West Indies who contracted dengue were said to have "dandy fever" because of their postures and gait.
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Diagnosis: 1 The nature of a disease ; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies . 3 The identification of any problem. The diagnosis was a plugged IV.
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Dysentery: Inflammation of the intestine, often with pain, diarrhea , bloody stools, etc. It is usually caused by infestation of the bowel by an ameba. Dysentery can be fatal, usually due to severe dehydration . Treatment includes rapid rehydration, sometimes via IV, and medication. From the Greek "dys-" meaning "abnormal or painful" + "enteron" meaning "intestine" = abnormal or painful intestine.
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Emergency department: The department of a hospital responsible for the provision of medical and surgical care to patients arriving at the hospital in need of immediate care. Emergency department personnel may also respond to certain situations within the hospital such cardiac arrests.
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Encephalitis: Inflammation of the brain. Encephalitis occurs, for example, in 1 in 1,000 cases of measles . It may start (up to 3 weeks) after onset of the measles rash and present with high fever , convulsions, and coma. It usually runs a blessedly short course with full recovery within a week. Or it may eventuate in central nervous system impairment or death.
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Epidemic: The occurrence of more cases of a disease than would be expected in a community or region during a given time period. A sudden severe outbreak of a disease such as SARS. From the Greek "epi-", "upon" + "demos", "people or population" = "epidemos" = "upon the population." See also: Endemic; Pandemic.
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Epidemic typhus: See: Typhus, epidemic .
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Epinephrine: A substance produced by the medulla (inside) of the adrenal gland. The name epinephrine was coined in 1898 by the American pharmacologist and physiologic chemist (biochemist) John Jacob Abel who isolated it from the adrenal gland which is located above (epi-) the kidney ("nephros" in Greek). (Abel also crystallized insulin ). Technically speaking, epinephrine is a sympathomimetic catecholamine. It causes quickening of the heart beat, strengthens the force of the heart's contraction, opens up the airways (bronchioles) in the lungs and has numerous other effects. The secretion of epinephrine by the adrenal is part of the fight-or-flight reaction. Adrenaline is a synonym of epinephrine and is the official name in the British Pharmacopoeia.
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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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Fire ant sting: A scourge, these red or yellow ants of small-to-medium size, originally from South America, have a severe sting that burns like fire. Their sting-like that of bees, yellow jackets, hornets and wasps -- can trigger allergic reactions varying greatly in severity. Avoidance and prompt treatment are essential. In selected cases, allergy injection therapy is highly effective. (The three "A's" of insect allergy are Adrenaline, Avoidance and Allergist.)
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Fire ants: Originally from S. America. Among the worst insect pests ever to invade the US. Red or yellowish ants of small-to-medium size with a severe sting that burns like fire. They normally feed on small insects but, with denser populations, they eat seeds and seedling plants, damage grain and vegetable crops, invade kitchens, attack newly hatched poultry and the young of ground-nesting wild birds. Fire ants can kill newborn domestic and wild animals. Each colony is composed of a queen, winged males and females and 3 kinds of workers. A nest averages about 25,000 workers, but far larger populations are common. Semipermanent nests are large mounds of excavated soil with openings for ventilation. Since nests may number 50-100 (or more) in a heavily infested field, cultivating becomes difficult (or impossible). Fire ants belong to the genus Solenopsis. The severe sting of this ant causes a pustule to form within 24 hours that takes 10-14 days to resolve. Fire ant toxin can trigger an allergic reaction, particularly in people allergic to bee, wasp and yellowjacket stings. Avoidance and prompt treatment are essential.
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Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest.
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Hives: A raised, itchy area of skin that is usually a sign of an allergic reaction. It can be rounded or flat-topped but is always elevated above the surrounding skin. It reflects circumscribed dermal edema (local swelling of the skin). The hives are usually well circumscribed but may be coalescent and will blanch with pressure. They typically last less than 4 hours but they may stay for days or weeks. Approximately 20% of the population has experienced a bout of hives.
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Hornet sting: Stings from hornets and other large stinging insects such as bees, yellow jackets and wasps can trigger allergic reactions varying greatly in severity. Avoidance and prompt treatment are essential. In selected cases, allergy injection therapy is highly effective. (The three "A's" of insect allergy are Adrenaline, Avoidance and Allergist.)
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Hospital: It may seem unnecessary to define a "hospital" since everyone knows the nature of a hospital. A hospital began as a charitable institution for the needy, aged, infirm, or young.
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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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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 .
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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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Jaw: The bones below the mouth (the mandible) and the bone above the mouth just above the mouth (the maxilla). The word jaw comes from the Anglo-Saxon ceowan meaning to chew.
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Kidney: One of a pair of organs located in the right and left side of the abdomen which clear "poisons" from the blood, regulate acid concentration and maintain water balance in the body by excreting urine. The kidneys are part of the urinary tract. The urine then passes through connecting tubes called "ureters" into the bladder. The bladder stores the urine until it is released during urination.

Leishmania: A group of parasites causing a disease called leishmaniasis . For a fuller definition and more information, see Leishmania infection .
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Leishmaniasis: Diseases due to the parasite called Leishmania involving the organs (kala-azar) or the skin plus mucous membranes (espundia), or the skin alone (usually named for the place plus boil, button or sore as, for example, Jericho boil, Bagdad button, Delhi sore).
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Lyme disease: Lyme disease is a bacterial illness caused by a bacterium called a "spirochete." Lyme disease is spread by ticks when they bite the skin. Lyme disease can cause abnormalities in the skin, joints, heart and nervous system.
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Malaria : An infectious disease caused by protozoan parasites from the Plasmodium family that can be transmitted by the sting of the Anopheles mosquito or by a contaminated needle or transfusion. Falciparum malaria is the most deadly type.
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Muscle: Muscle is the tissue of the body which primarily functions as a source of power. There are three types of muscle in the body. Muscle which is responsible for moving extremities and external areas of the body is called "skeletal muscle." Heart muscle is called "cardiac muscle." Muscle that is in the walls of arteries and bowel is called "smooth muscle."
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Obstruction: Blockage of a passageway. See, for example: Airway obstruction ; Intestinal obstruction .
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Open wound: An injury that is exposed due to broken skin. An open wound is at high risk for infection.
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Oxygen: A colorless, odorless and tasteless gas that makes up about 20% of the air we breathe (and at least half the weight of the entire solid crust of the earth) and which combines with most of the other elements to form oxides. Oxygen is essential to human, animal and plant life.
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Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse, as in disorders like fibromyalgia . Pain is mediated by specific nerve fibers that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors.
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Pharmacy: A location where prescription drugs are sold. A pharmacy is, by law, constantly supervised by a licensed pharmacist.
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Plague: The plague is an infectious disease due to a bacteria called Yersinia pestis .
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Poisoning: Taking a substance that is injurious to health or can cause death. Poisoning is still a major hazard to children, despite child-resistant (and sometimes adult-resistant) packaging and dose-limits per container.
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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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Pus: A thick whitish-yellow fluid which results from the accumulation of white blood cells (WBCs), liquified tissue and cellular debris. Pus is commonly a site of infection or foreign material in the body.
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Pustule: A pustule is a small collection of pus in the top layer of skin (epidermis) or beneath it in the dermis. Pustules frequently form in sweat glands or hair follicles. Pus is a mixture of inflammatory cells and liquid.
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Relapsing fever: An acute infection with recurrent episodes of fever caused by spirochetes of the genus Borrelia which are borne by ticks or lice. The relapsing nature of the fever is associated with the presence of antigenic variants. As an immune response develops to the predominant antigenic strain, variant strains multiply and cause a recrudescent infection.
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Respiratory: Having to do with respiration, the exchange of oxygen and carbon dioxide. From the Latin re- (again) + spirare (to breathe) = to breathe again.
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Respiratory system: The organs that are involved in breathing. These include the nose, throat, larynx, trachea, bronchi, and lungs.
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Rickettsia: A member of a group of microorganisms that (like viruses) require other living cells for growth but (like bacteria) use oxygen, have metabolic enzymes and cell walls, and are susceptible to antibiotics. Rickettsiae cause a series of diseases named for the American pathologist Howard Ricketts who discovered that ticks spread Rocky Mountain spotted fever and then isolated from the blood of infected animals and eggs of infected ticks the microorganism responsible for Rocky Mountain spotted fever, typhus, trench fever and other similar conditions. While in Mexico in 1910 studying a typhus epidemic, Ricketts contracted the disease and died at age 39.(See Rickettsial diseases).
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Sensation: In medicine and physiology , sensation refers to the registration of an incoming ( afferent ) nerve impulse in that part of the brain called the sensorium , which is capable of such perception. Therefore, the awareness of a stimulus as a result of its perception by sensory receptors. (Sensory is here synonymous with sensation.)
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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.

Snake: 1. A long limbless scaly reptile, some being poisonous. 2. The symbol of rejuvenation and healing in many ancient Mediterranean cultures. The Greek god Asclepius, who specialized in healing, had a single snake entwined around his staff -- the "Asclepian staff."
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Sore: 1. (adjective) A popular term for painful. I have sore fingers from typing dictionary terms. She has a sore throat . 2. (noun) A nondescript term for nearly any lesion of the skin or mucous membranes. He has a number of sores in his mouth.

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Symptom: Any subjective evidence of disease. Anxiety, lower back pain , and fatigue are all symptoms. They are sensations only the patient can perceive. In contrast, a sign is objective evidence of disease. A bloody nose is a sign. It is evident to the patient, doctor, nurse and other observers.
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Systemic: Affecting the entire body. A systemic disease such as diabetes can affect the whole body. Systemic chemotherapy employs drugs that travel through the bloodstream and reach and affect cells all over the body.
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Therapy: The treatment of disease .
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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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Tongue: The tongue is a strong muscle anchored to the floor of the mouth. It is covered by the lingual membrane which has special areas to detect tastes.
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Toxicity: The degree to which a substance can harm humans or animals.
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Trigger: Something that either sets off a disease in people who are genetically predisposed to developing the disease, or that causes a certain symptom to occur in a person who has a disease. For example, sunlight can trigger rashes in people with lupus .
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Tularemia: A bacterial disease caused by infection with a bacterium called Francisella tularensis that usually occurs in wild and domestic animals, most often rabbits, and can be transmitted to humans by contact with animal tissues or ticks and fleas. Also called rabbit fever and deerfly fever.
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Typhoid: See: Typhoid fever .
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Typhus: One of a group of acute infections caused by rickettsiae , transmitted by arthropods (lice, fleas, mites), and characterized by severe headache, chills, high fever, stupor, and a rash. The four main entities making up the group are epidemic typhus, its recrudescent form (Brill-Zinsser disease), murine typhus, and scrub typhus. Called also typhus fever. See also: Brill-Zinsser disease ; Epidemic typhus ; Murine typhus ; Scrub typhus .
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Vector: In medicine, a vector is a carrier. The best way to understand a vector is to recall its origin as a word. Vector is the Latin word for a "bearer."
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Venom: A poison , particularly one secreted by an animal. For examples, bee venom, snake venom, scorpion venom, and spider venom. Snake venom is also called venin .
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Viral: Of or pertaining to a virus. For example, "My daughter has a viral rash ."
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Virus: A microorganism smaller than a bacteria, which cannot grow or reproduce apart from a living cell. A virus invades living cells and uses their chemical machinery to keep itself alive and to replicate itself. It may reproduce with fidelity or with errors (mutations)-this ability to mutate is responsible for the ability of some viruses to change slightly in each infected person, making treatment more difficult.
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Wasp sting: A sting from a wasp, like that of other large stinging insects such as bees, hornets and yellow jackets, capable of triggering allergic reactions varying greatly in severity and scope from a localized reaction limited to swelling of the hand or foot (where the bite occurred) to life-threatening systemic (bodywide) reactions in which the airway can swell closed.
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West Nile virus: The mosquito-borne virus that causes West Nile fever . One of the flaviviruses, a family of viruses also responsible for dengue , yellow fever , and tick-borne encephalitis virus. Like the other flaviviruses, the West Nile virus is a positive-strand RNA virus containing three structural proteins and a host-derived lipid bilayer. The West Nile virus is an icosahedral structure of about 500 angstroms in diameter. The overall structure of the West Nile virus most closely resembles that of dengue fever virus but the surface proteins are slightly different, which may give West Nile virus some of its unique features.
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Wheezing: A whistling noise in the chest during breathing when the airways are narrowed or compressed.
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Yellow fever: An acute systemic (bodywide) illness caused by a virus called a Flavivirus . In severe cases, the viral infection causes a high fever, bleeding into the skin, and necrosis (death) of cells in the kidney and liver. The damage done to the liver from the virus results in severe jaundice which yellows the skin. Hence, the "yellow" in "yellow fever."
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Yellow jacket sting: A sting from a yellow jacket (or other large stinging insects such as bees, hornets and wasps) can trigger allergic reactions ranging from local responses of limited duration to catastrophic general reactions which can be fatal. The susceptibility to severe reactions appears inherited. Avoidance and prompt treatment are essential. Immediate treatment is with adrenaline by injection. In selected cases, allergy injection therapy is highly effective in desensitizing the patient. The three A's of large stinging insect allergy are Adrenaline, Avoidance and Allergist.
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