| AECD | allergic eczematous contact dermatitis |
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| AGA | accelerated growth area; allergic granulomatosis and angiitis; American Gastroenterological Associat... |
| Al | allantoic; allergic, allergy; aluminum |
| all | allergy, allergic |
| AR | absolute risk; accounts receivable; achievement ratio; actinic reticuloid [syndrome]; active resista... |
| vasculitis, allergic cutaneous | Vasculitis due to allergic reaction, marked by such cutaneous lesions as papules, macules, vesicles, urticarial wheals, purpura, and small ulcers, and accompanied by itching and usually a slight fever and malaise. (12 Dec 1998) |
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| reaction, allergic | A reaction that occurs when the immune system attacks a usually harmless substance (an allergen) that gains access to the body. The immune system calls upon a protective substance called immunoglobulin e (IgE) to fight these invading allergic substances ( allergens). Even though everyone has some IgE, an allergic person has an unusually large army of these IgE defenders -in fact, too many for their own good. This army of IgE antibodies attacks and engages the invading army of allergic substances of allergens. As is often the case in war, innocent bystanders are affected by this battle. These innocent bystanders are special cells called mast cells. These cells are frequently injured during the warring of the IgE antibodies and the allergic substances. When a mast cell is injured, it releases a variety of strong chemicals including histamine into the tissues and blood that frequently cause allergic reactions. These chemicals are very irritating and cause itching, swelling, and fluid leaking from cells. These allergic chemicals can cause muscle spasm and can lead to lung and throat tightening as is found in asthma and loss of voice. (12 Dec 1998) |
| rhinitis, allergic | The medical term for hayfever. (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. (12 Dec 1998) |
| rhinitis, allergic, perennial | Allergic rhinitis (hayfever) that occurs throughout the year. (12 Dec 1998) |
| rhinitis, allergic, seasonal | Allergic rhinitis (hayfever) which occurs during a specific season. (12 Dec 1998) |
| conjunctivitis, allergic | Conjunctivitis due to hypersensitivity to various allergens. (12 Dec 1998) |
| neuritis, experimental allergic | An autoimmune demyelinating disorder of peripheral nerves produced by injection of peripheral nerve tissue protein. (12 Dec 1998) |
| dermatitis, allergic contact | A contact dermatitis due to allergic sensitization to various substances. These substances subsequently produce inflammatory reactions in the skin of those who have acquired hypersensitivity to them as a result of prior exposure. (12 Dec 1998) |
| encephalomyelitis, allergic | An experimental demyelinating disease produced in animals by injections of myelin fractions in order to study the relationship between hypersensitivity and the demyelinating diseases. (12 Dec 1998) |
| experimental allergic encephalitis | <pathology> An autoimmune disease that can be induced in various experimental animals by the injection of homogenised brain or spinal cord in Freund's adjuvant. The antigen appears to be a basic protein present in myelin and the response is characterised by focal areas of lymphocyte and macrophage infiltration into the brain, associated with demyelination and destruction of the blood-brain barrier. Sometimes used as a model for demyelinating diseases, although whether this is entirely justifiable is not clear. (18 Nov 1997) |
| experimental allergic encephalomyelitis | <pathology> An autoimmune disease that can be induced in various experimental animals by the injection of homogenised brain or spinal cord in Freund's adjuvant. The antigen appears to be a basic protein present in myelin and the response is characterised by focal areas of lymphocyte and macrophage infiltration into the brain, associated with demyelination and destruction of the blood-brain barrier. Sometimes used as a model for demyelinating diseases, although whether this is entirely justifiable is not clear. (18 Nov 1997) |
| extrinsic allergic alveolitis | <radiology> Exposure to organic dust less than 5u in size, recurrent episodes of fever, chills, dry cough, dyspnea following exposure after 6 hr interval (10-40% assymptomatic), spontaneous resolution in 1-2 days, farmer's lung, Pandora's pneumonitis, bird-fancier's lung, mushroom worker's lung, bagassosis, malt worker's lung, maple bark disease, suberosis, sequoiosis see: acute extrinsic allergic alveolitis, hypersensitivity pneumonitis (12 Dec 1998) |