alergy

Allergies, also known as allergic diseases, are a number of conditions caused by hypersensitivity [超敏感度] of the immune system [免疫系统] to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis [特应性皮炎], allergic asthma [哮喘], and anaphylaxis [a serious life-threatening allergic reaction]. Symptoms [症状] may include red eyes, an itchy rash [疹子], sneezing [打喷嚏], a runny nose [流鼻涕], shortness of breath [呼吸困难], or swelling [肿胀].] Food intolerances [不耐受] and food poisoning are separate conditions.

Common allergens [致敏物] include pollen [花粉] and certain foods. 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 [免疫球蛋白] E antibodies [抗体] (IgE), part of the body's immune system, binding to an allergen and then to a receptor [感受细胞] on mast cells [肥大细胞] or basophils [嗜碱性细胞] where it triggers the release of inflammatory [发炎性的] chemicals such as histamine [组胺]. Diagnosis is typically based on a person's medical history. Further testing of the skin or blood may be useful in certain cases. Positive [阳性] tests, however, may not mean there is a significant allergy to the substance in question.

Allergies are common. In the developed world, about 20% of people are affected by allergic rhinitis [鼻炎], 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.

Signs and symptoms [迹象与症状]

• Nose Swelling of the nasal mucosa [鼻黏膜] (allergic rhinitis) runny nose, sneezing
• Sinuses[鼻窦] Allergic sinusitis [鼻窦炎]
• Eyes Redness and itching of the conjunctiva [结膜] (allergic conjunctivitis, watery)
• Airways Sneezing, coughing, bronchoconstriction [支气管狭窄], wheezing and dyspnea [喘息和呼吸困难], sometimes outright [立即] attacks [发作] of asthma, in severe cases the airway constricts due to swelling known as laryngeal edema [喉水肿]
• Ears Feeling of fullness, possibly pain, and impaired [受损的] hearing due to the lack of eustachian tube [咽鼓管] drainage.
• Skin Rashes, such as eczema and hives (urticaria) [湿疹和荨麻疹]
• Gastrointestinal tract [消化道] Abdominal pain, bloating, vomiting, diarrhea

{百度百科} 鼓室并不是完全封闭的，它通过咽鼓管与鼻咽部相通。咽鼓管长约35毫米，高度差为15～25毫米。鼻咽部的液体不容易逆流而上进入中耳。咽鼓管的主要作用是: 1. 调节鼓室中的压力; 2. 引流:把鼓室中的分泌物排出。近鼻咽段的咽鼓管平时关闭。吞咽/打哈欠/唱歌或用力擤鼻涕时打开。

Many allergens such as dust or pollen are airborne particles. In these cases, symptoms arise in areas in contact with air, such as eyes, nose, and lungs. For instance, allergic rhinitis, also known as hay fever, causes irritation [不适感] of the nose, sneezing, itching, and redness of the eyes. Inhaled [吸入的] allergens can also lead to increased production of mucus [黏液] in the lungs, shortness of breath, coughing, and wheezing.

1955年前，“黏”是正体字，“粘”是俗体字。据1955年的《第一批异体字整理表》，“黏”成为为异体字。据1988年的《通用规范汉字表》，“黏”和“粘”都是规范字，但词义不同。“粘”/zhān/是动词，只在作姓时才发nián音。

A wide variety of foods can cause allergic reactions, but 90% of allergic responses to foods are caused by cow's milk, soy, eggs, wheat, peanuts, tree nuts, fish, and shellfish. Other food allergies, affecting less than 1 person per 10,000 population, may be considered "rare". The use of hydrolysed milk baby formula [水解婴儿配方奶] versus standard milk baby formula does not appear to change the risk.

The most common food allergy in the US population is a sensitivity to crustacea [甲壳类]. Although peanut allergies are notorious for their severity, peanut allergies are not the most common food allergy in adults or children. Severe or life-threatening reactions may be triggered by other allergens, and are more common when combined with asthma.

一般来说，大的厚的读qiào，如地壳。小的薄的，读ke2，如甲壳虫。

Allergic diseases are strongly familial [与family有关]: identical twins [双胞胎] are likely to have the same allergic diseases about 70% of the time; the same allergy occurs about 40% of the time in non-identical twins. Allergic parents are more likely to have allergic children,] and those children's allergies are likely to be more severe than those in children of non-allergic parents. Some allergies, however, are not consistent along genealogies [family tree]; parents who are allergic to peanuts may have children who are allergic to ragweed [北美豚草]. It seems that the likelihood of developing allergies is inherited and related to an irregularity in the immune system, but the specific allergen is not.

Chronic stress [慢性压力] can aggravate [加重] allergic conditions. Allergic diseases are more common in industrialized countries than in countries that are more traditional or agricultural, and there is a higher rate of allergic disease in urban populations versus rural populations, although these differences are becoming less defined. Historically, the trees planted in urban areas were predominantly male to prevent litter from seeds and fruits, but the high ratio of male trees causes high pollen counts.

Skin prick tests [皮肤点刺试验] and blood tests are equally cost-effective, and health economic evidence shows that both tests were cost-effective compared with no test. Also, early and more accurate diagnoses save cost due to reduced consultations, referrals to secondary care, misdiagnosis, and emergency admissions.

Allergy undergoes dynamic changes over time. Regular allergy testing of relevant allergens provides information on if and how patient management can be changed, in order to improve health and quality of life. Annual testing is often the practice for determining whether allergy to milk, egg, soy, and wheat have been outgrown, and the testing interval is extended to 2–3 years for allergy to peanut, tree nuts, fish, and crustacean shellfish. Results of follow-up testing can guide decision-making regarding whether and when it is safe to introduce or re-introduce allergenic food into the diet.

六级/考研单词: immune, hay, fever, symptom, rash, swell, poison, insect, sting, medicare, underlie, bind, trigger, diagnose, farther, affection, cough, impair, hive, tract, airborne, particle, lung, irritate, wheat, peanut, nut, versus, notorious, twin, consistent, irregular, chronic, aggravate, differentiate, predominant, litter, heal, undergo, dynamic, regulate, seldom, interval