ALLERGY, a hypersensitive response of the body to foreign substances. Such foreign substances, known as antigens, stimulate the body to produce antibodies—molecules whose normal function is to combat antigens by destroying them or otherwise making them harmless. In allergic individuals, for poorly understood reasons, the body’s antibody defense mechanism goes awry and injures the body instead of protecting it.

过敏，身体对外来物质的一种超敏反应。这种被称为抗原的外来物质会刺激身体产生抗体---这些分子的正常功能是破坏它们或使它们无害来对抗抗原。在过敏的个体中，由于尚未了解的原因，身体的抗体防御机制出现了差错，伤害到身体，而没有保护身体。

Antigens may include almost all substances that are foreign to the body. These substances are not necessarily toxic or irritative in the absence of an allergy. They may be inhaled (bacteria, molds, pollens), ingested (foods, drugs), injected (biological such as serums, vaccines, or drugs), or in some cases introduced through contact with the skin (poison oak, chemicals in cosmetics and dyes). Some chemically simple antigens have the capacity to combine spontaneously with the proteins of the subject’s own tissues. The body treats the resulting combination, or complex, as foreign.

抗原可能包括了几乎所有对身体的外来物质。这些物质在没有过敏的情况下不一定都是有毒的或刺激性的。它们可能被吸入（细菌、霉菌、花粉），可能被摄入（食物、药品），可能被注射（生物的，诸如血清、疫苗或药物），或者在某些情况下通过皮肤接触引入（毒葛、化装品和染料中的化学物质）。一些化学上简单的抗原有能力自发地与实验对象自己组织中的蛋白质结合。身体将由此产生的组合或合成视为外来物。

IMMUNE MECHANISMS

Allergic states are of two major categories, immediate and delayed. In immediate allergy, the subject, as a result of an initial exposure to an antigen, has developed antibodies—proteins that are highly specific in combining with the antigen that induced their synthesis. Once antibody molecules are present, re-exposure to the appropriate antigen is followed by rapid combination of antibody and antigen, with consequences described below.

免疫机制

过敏的状态主要有速发性和迟发性两类。在速发性过敏中，作为最初接触抗原的结果，实验对象产生了抗体---在与诱发它们合成的抗原结合中具有高度特殊功能的蛋白质。一旦出现了抗体微粒，随后再次接触到合适的抗体便迅速结合成抗体和抗原，结果如下所述。

Delayed allergy depends on a similarly specific reactive state that is a property of certain cells of the body (lymphoid cells) rather than of molecules in solution. Upon re-exposure to the antigen, the sensitized subject shows a response only after some hour, because the appropriately sensitive cells must migrate via the blood and lymph to accumulate in the organ or tissue where the antigen is present. There they produce toxic chemical mediators that cause the symptoms of the allergy.

迟发性过敏依赖于一种类似特定的反应状态，它是身体某些细胞（淋巴样细胞）的一种性质，而不是溶液中的分子。一旦再次接触抗原，致敏化的实验对象在几个小时后才会出现反应，因为适当的敏感细胞必须通过血液和淋巴转移才能在抗原存在的器官或组织中积累。它们在那里产生了有毒化学介质，因此引发了过敏症状。

Immediate Allergy. The categories of immediate allergic responses are referred to as atopy, anaphylaxis, and Arthus reactions. They are antibody-mediated allergies, and their immunologic mechanisms are basically the same.

速发性过敏。速发性过敏的类别被称为特异反应性、过敏性反应以及阿瑟氏反应。它们都是抗体媒介的过敏，而且它们的免疫学机制基本一样。

Atopy. This type of reaction occurs in humans who have been sensitized spontaneously to inhaled or ingested antigens, particularly pollens and mixed dusts in the air, or milk, fish, nuts, and eggs among foods. If the reaction to inhaled substances causes inflammation of nasal passages, it is called hay fever. The symptoms of hay fever result from dilation of the capillaries in the mucous membranes of the nose, with consequent leakage of fluid into adjoining tissues. Sometimes the eyes become inflamed because of dilation of the capillaries in their mucous membranes. An attack of asthma may result, mainly from contraction of smooth (involuntary) muscle around the small bronchioles (branching tubes in the lungs). Hives, gastrointestinal distress, or infantile eczema also may develop. A single individual may show a combination of these signs and symptoms.

特异反应性。这种反应类型出现在那些吸入或摄入抗原，自然致敏的人群中，尤其是空气中的花粉和混合粉尘，或食物中的牛奶、鱼类、坚果和鸡蛋。如果吸入物质的反应引发鼻道发炎，就可称为花粉热。花粉热的症状起因于鼻子粘膜中毛细血管的扩张，导致液体渗漏进相邻的组织中。有时眼睛会发炎，是因为在它们粘膜中的毛细血管的扩张。可能会使哮喘发作，主要是小细支气管（肺部的分支管）周围的平滑肌收缩所致。荨麻疹，也可能产生肠胃不适，或婴儿湿疹。一个人可能会出现这些体征和症状的混合情况。

The class of antibody globulin concerned in atopic reaction has a marked tendency to become bound to tissues (basophilic cells) and to cause the release of pharmacologically active mediators once combination with antigen has taken place. These mediator include histamine, SRS-A (slow reactive substance-A), serotonin, bradykinin, and other substances that affect the capillaries and smooth muscles.

涉及特应性反应的抗体球蛋白类别拥有与组织（嗜碱细胞）结合的明显趋势，一旦与抗原结合就会产生导致药理活性介质的释放。这些介质包括组胺，SRS-A（慢反应物质-A），血清素，缓激肽以及其它影响毛细血管和平滑肌的物质。

Atopic allergies run in family lines. Both the general capacity to become sensitized and specific reactivities to particular substances are genetically determined.

特应性过敏在家族中遗传。对由遗传决定的特定物质，会成为致敏化和特殊反应的一般能力。

The common procedure for detecting the antigenic cause in atopic allergy involves skin tests using a variety of possible antigens. The antigen are rubbed into scratches or injected. Those to which the subject is sensitive cause a local swelling or hives within a few minutes of exposure. The tests are most successful, however, in those subjects whose seasonal difficulties are caused by pollens. Antibodies associated with atopic allergies can also be detected in the test tube.

在特应性过敏中检测抗原原因的一般程序包括使用多种可能的抗原进行皮肤测试。抗原被擦入或注入划痕中。实验对象的那些敏感部位会在接触后的几分钟内产生局部肿胀或荨麻疹。然而，在那些由花粉引起的季节性症状的实验对象中，这些测试是最成功的。在试管检测中也可能检测到与特应性过敏相关的抗体。

Anaphylaxis. The term anaphylaxis is applied to allergic reactions that result in a systemic reaction affecting the whole body, especially when the reaction results from injections of antigen. Anaphylaxis may be induced in virtually anyone, provided the person has responded to a first exposure to an antigen by producing antibodies that become bound to body tissues. Following a second exposure to the same antigen, the bloodstream carries the antigen to the previously sensitized tissues. There the antigen combines with the antibodies and causes the release of histamine and other pharmacologically active substances mentioned in the preceding section. A systemic reaction, which affects the entire body, can occur within minutes, or even seconds, after injection of the antigen. Such a reaction is marked mainly by difficulty in breathing, although contractions of smooth muscle in parts of the body less vital than the lungs may also occur.

过敏性反应。过敏性反应一词是指引发一种系统的影响全身的过敏反应，特别是在注射了抗原时所引发的反应。几乎任何人都有可能产生过敏性反应，只要这个人在首次接触抗原时产生了与身体组织结合抗体的反应。之后，在第二次接触相同的抗原时，循环的血液携带着抗原到达先前已致敏化的组织。在此，抗原与抗体结合并导致在前一节中提到的组胺和其它药理活性物质的释放。在注射了抗原之后，几分钟，甚至几秒内就会出现一种影响整个身体的系统反应。这种反应主要表现为呼吸困难，虽然身体中部分平滑肌的收缩不如肺部那么至关重要，但也可能会发生。

Anaphylactic reactions typically are caused by injections of drugs or by sting of bees and other insect. Physicians are particularly concerned about the severity of anaphylactic reactions to the injection of large-molecule proteins, such an antitoxins, because these substances are highly antigenic.

过敏反应通常是由药物注射或蜜蜂和其它昆虫蛰伤引起的。医生对注射大分子蛋白质过敏的严重性尤其关注，如抗毒素类，因为这些物质是高度抗原性的物质。

Local anaphylactic reactions also may occur when an antigen is injected into a tissue, such as the skin, from which diffusion does not occur readily. This may show itself as a local hive. But in a highly sensitive subject, even this route of exposure may elicit a systemic reaction. See also ANAPHYLAXIS.

当抗原被注射到组织中时，也可能出现局部过敏反应，比如皮肤，从皮肤不会迅速扩散。这会出现一种局部红肿。但在高度敏感的实验对象中，甚至是这种接触性的方法都可能引发系统反应。可参阅过敏性反应词条。

Arthus Reaction. This type of reaction appears in the sensitive subject several hours after exposure to an antigen. It is manifested by local swelling and redness, which may disappear in 24 hours or progress to the local death of tissue. It differs from the more fleeting anaphylactic reaction in two main ways: the class antibody concerned in the Arthus reaction is not of the tissue-fixed kind, and a high concentration of the antibody must be present in the blood. The amount of antigen required to elicit the reaction also must be relatively large. The interaction of antibody with antigen occurs in the walls of the blood vessels as the antigen diffuses and meets the antibody from the circulation or small complexes of antigen and antibody may invade the vessel walls.

阿瑟氏反应。在接触抗原后，这种反应几小时后出现在敏感的实验对象身上。局部出现红肿，可在24小时内消失或达到局部组织死亡。它与更短暂的过敏反应有两个主要区别：在阿瑟氏反应中涉及的类抗体不是固定的组织类型，在血液中必须存在高浓度的抗体。引起反应的抗原数量也必须是相对较大的。随着抗原扩散并遇到来自血液循环或抗原和抗体的小复合物，以及抗体可能会侵入血管壁时，在血管壁中就会出现抗体与抗原的相互作用。

Serum Sickness. The various categories of immediate allergic reaction are not mutually exclusive, and there may be a combination of them. Such a combination occurs in serum sickness. The term derives from the time in which serum therapy was common. Many individuals who received horse or other foreign serum developed late signs of an immediate type of allergic reaction (usually in the form of hives, pain in the joints, rash, and fever). Their appearance was delayed because the subject had not previously experienced the serum antigens and thus had to produce antibodies before a reaction could occur.

血清病。速发性过敏反应的各种分类并不相互排斥，而且它们可能存在一种结合。这样的结合出现在血清病中。该术语出自血清病治疗很普遍的时代。许多接受了马或外来血清的个体都出现了速发性过敏反应的晚期症状（通常表现为荨麻疹、关节疼痛、皮疹、发热）。他们的症状被延迟，是由于实验对象先前经历过血清抗原，因此在反应发生前必须产生抗体。

The term “serum sickness” still is applied to this syndrome even though it now appears mainly following the administration of drugs such as penicillin, streptomycin, and the sulfonamides. Although the symptoms of serum sickness usually disappear after a few days or weeks, complications in the kidneys, heart, or joints may occur following a persistent injury, especially to blood vessels, by antigen-antibody complexes.

即使现在它主要出现在下列用药的情况下，如青霉素、链霉素以及磺胺类药，“血清病”这个词依然适用于这类综合症。尽管血清病的症状通常在几天或几周内消失，但由于抗原-抗体的复合物，尤其是对血管接下来持续的损伤，肾脏、心脏或关节可能会出并发症。

Delayed Allergy. This is a hypersensitive state in which lymphoid cells participate as the specific reactive agents, perhaps as carrier of partial antibodies on their surfaces. Characteristically, it results from infections, especially from those in which the infecting microbe tends to reside in cells. The classical example among bacterial diseases is tuberculosis.

迟发性过敏。这是一种淋巴样细胞作为特定反应介质参与的超敏状态，也许是它们表面部分抗体的载体。特征是，这是由感染引起的，尤其是从那些倾向于驻留在细胞内，感染微生物的细胞。在细菌性疾病中的典型例子就是结核病。

The same kind of allergic state results from contact of the skin with some simple chemical, including the one responsible for poison-ivy rash. The reasons for the development of this kind of reactivity during infection or after exposure of the skin to certain antigens are not known.

由皮肤接触的一些简单化学制品造成的同样过敏状态，包括一种导致毒葛皮疹的化学制品。目前尚不清楚在感染期或皮肤接触某些抗原后发生这种反应的原因。

A similar delayed allergy is involved in the body’s rejection of tissues grafted from one to another individual and in its rejection of tumors. Donor tissues or organs are acted upon mainly by cells that have become specifically reactive against antigens contained in them. Conventional antibodies also may be produced against such tissue antigens, but these are not involved ordinarily in the rejection process, perhaps because they cannot effectively damage the cells composing a compact tissue, as infiltrating reactive cells can.

类似的迟发性过敏涉及到身体对由一个个体到另一个个体移植组织的排斥，以及它对肿瘤的排斥。捐献的组织或器官主要受细胞的作用，即针对它们中包含的抗原产生特异性反应。针对这种组织的抗原也可能产生常规的抗体，但这些一般都不涉及排斥的过程，也许是因为它们无法像浸润性反应细胞那样有效地损坏组成紧密组织的细胞。

Delayed allergic reactivity also is implicated in some of the so-called “immunologic diseases,” in which a subject spontaneously becomes reactive against constituent of his own tissues. This immunologic paradox is also called autoimmunization.

迟发性过敏的反应也涉及到一些所谓的“免疫学疾病”，其中，实验对象自发地对构成它自己的组织产生反应。这种免疫学的悖论也被称为自身免疫。

Hereditary Aspects. Genetic constitution influences the allergic state in two ways. In a singular sense, individuals may be unable to respond to a particular antigen because they lack the genes that direct the production of the reactive substance specific for the antigen. Heredity also influences the development of allergy in a more general sense, as exemplified by people who show an unusual capacity to respond not to particular antigens but in general to environmental antigenic agents that induce atopic hyper-sensitivity. Such responses may be related to genetically determined absorptions or processing of antigen by the body.

遗传方面。基因组成在两个方面影响过敏的状态。从某种意义上说，个体可能无法对特殊的抗原做出回应，因为它们缺乏那些引导产生抗原特异性反应物质的基因。从更普遍的意义上说，遗传性也会影响过敏的发展，以某些人为例，他们表现出不寻常的能力，对特定抗原不产生反应，而一般说来却对引起特应性超敏环境的抗原介质做出反应。

 

ALLERGIC DISORDERS

Allergic disorders may result from any of the immune mechanisms discussed in the preceding section. The immediate types are mediated by antibodies, and the delayed types remediated by sensitized lymphocytes. The immediate types are more numerous and potentially more life-threatening. In severe cases they may result in a general systemic shock of the anaphylactic type. But more usually the immediate allergies manifest themselves by hives or angioedema (leakage of fluid through blood-vessel walls). The delayed reactions include contact dermatitis with localized eczema, as in reactions to poison ivy or poison oak, or a generalized rash, as in reactions following the swallowing of a drug.

过敏紊乱

过敏紊乱可能是由在前一节讨论的任何免疫机制造成的。速发性的类型是由抗体引起的，而迟发性的类型是由致敏的淋巴球引起的。速发性的类型数量更多，而且对生命的威胁更大。在严重的情况下，它们会导致过敏性的全身休克。但更常见的速发性过敏是通过荨麻疹或血管性水肿（通过血管壁的液体渗漏）呈现的。迟发性的反应包括带有局部湿疹的接触性皮炎，就像对毒葛或毒橡树，或广义的皮疹的反应一样，也像吞下药物后的那些反应。

Immediate. Disorders resulting from immediate hypersensitive reactivity include rhinitis, hives, asthma, serum sickness, and anaphylactic shock. All may be induced by antigens that act through respiratory and gastrointestinal membranes or by substances that are injected. These antigens may include a wide variety of pollens, dusts, foods, and drug, including biologic products such as hormones and vaccines.

速发性。由速发性超敏反应造成的紊乱包括鼻炎、荨麻疹、哮喘、血清病以及过敏性休克。所有这些都是由抗原通过呼吸系统和肠胃细胞膜或注射的物质诱发的。这些抗原可能包括各种各样的花粉、粉尘、食物以及药物，包括生物制品，诸如激素类和疫苗。

The treatment of these disorders varies with circumstances. Antihistaminic drugs may be useful for the control of hay fever but less useful for asthma. For asthma, cromolyn sodium, which hinders release of mediators by basophilic cells, may be helpful. Adrenaline or ephedrine and xanthine derivatives, such as aminophyilin, are sometimes useful. Adrenal cortical hormones (cortisone and its various analogs) may alleviate certain hypersensitive reactions by decreasing the inflammatory responses that are the hallmark of many of them or, if used in large enough quantities, by inhibiting antibody responses to some extent. Finally, in some reactive states, notably the atopic ones such as hay fever, efforts are made to desensitize the subject by means of graded injections of the antigens to which hypersensitivity has developed spontaneously.

对这些紊乱的治疗因情况而异。抗组胺剂药物对控制花粉热可能有效，但对哮喘没什么效果。对于哮喘，色甘酸钠会有助于阻断嗜碱细胞介质的释放。肾上腺素或麻黄碱以及黄嘌呤衍生物，诸如氨基茶碱有时是有用的。肾上腺皮质激素（肾上腺素皮质酮及其各种类似物）可通过减少炎症反应减轻某些超敏反应，它们都是炎症反应的标志，或者，如果用量足够大，在一定程度上会抑制抗体的反应。最终，在一些反应的状态中，尤其是特应性的情况，如花粉热，通过对自发形成的超敏反应分级注射抗原，尽量使实验对象脱敏。

Allergists believe that such injections, by introducing antigen through an “unnatural” route, may stimulate the formation of antibodies of a different molecular class from those induced via the natural route of sensitization through the mucous membranes. Such antibodies, which are less likely to provoke reactions when they combine with antigen, and which divert antigen from union with the spontaneously acquired kind of antibodies, are referred to as “blocking” antibodies.

一些过敏症专家认为，通过“非自然”的方法引入抗原的这种注射可以刺激形成不同于通过黏膜借助于自然的敏化途径诱发的不同分子类的抗体。这种抗体，当它们与抗原结合时不太可能引起反应，而且使抗原从自发获得的那种抗体结合中分离的抗体被称为“阻断”抗体。

Antibodies also appear to be implicated in autoimmune diseases, in which antibodies are directed against component of the subject’s own tissues or against antigens attached to cells. These include hemolytic anemia (antibodies active against red cells), myasthentia gravis (antibodies against acetylcholine receptors), rheumatoid arthritis (antibodies against a blood protein), and rheumatic fever (antibodies against heart and other muscle). Treatment of these diseases varies. Corticosteroids have been used in acquired hemolytic anemia (sometimes with removal of the spleen) and rheumatoid arthritis. In rheumatic fever, penicillin is useful in preventing recurrences of streptococcal infection that make the disease process more severe.

抗体似乎也与自身免疫疾病有关，其中抗体与实验对象自己的组织成分作对，或者与附属于细胞的抗原作对。这些包括溶血性贫血（针对红细胞的活性抗体），重症肌无力（针对乙酰胆碱受体的抗体），类风湿性关节炎（针对血液蛋白质的抗体），以及风湿热（针对心脏和其它肌肉的抗体）。对这些疾病的治疗各不相同。皮质类固醇一直被用于获得性溶血性贫血（有时伴随着切除脾脏）和类风湿性关节炎。在风湿热中，青霉素在预防使疾病过程更严重的链球菌感染的复发方面是有用的。

Delayed. Diseases that may result from delayed allergic reactivity include lesions caused by allergic destruction of tissue in infections such as tuberculosis. Noninfectious afflictions may result from delayed autoimmune reactions to constituents of the body tissues.

迟发性。可能导致迟发性过敏反应的疾病包括传染病中由组织过敏破坏引起的损伤。非传染必性的疾病可能是由构成身体组织的迟发性自身免疫反应造成的。

Another category of disease of this class is dermatitis caused by contact antigens such as certain plant substances and other simple chemicals. Plant substances responsible for contact dermatitis include catechols secreted by poison oak, poison ivy, and primula. Among the offending chemicals are some antibiotics and local anesthetics.

这类中的另一类疾病是由接触抗原引发的皮炎，比如某种植物物质和其它简单的化学制品。引起接触皮炎的植物物质包括毒橡树、毒葛以及樱草属植物分泌的儿茶酚类。在这些令人不适的化学物质中是一些抗生素和局部麻醉剂。

In all these cases, the antihistaminic agents that may be of use in certain of the immediate hypersensitivities are without value. The adrenocortical steroid hormone may alleviate these conditions by decreasing inflammatory reactions. Desensitization has been disappointing in the treatment of human disease.

在上述情况中，也许用于某些速发性的超敏抗阻胺剂介质是没有价值的。肾上腺皮质类固醇激素可通过减少炎症反应来减轻这些病症。在治疗人类的疾病中，脱敏疗法一直令人失望。

Common Allergies. The most familiar allergies are hay fever and asthma, which are caused by a wide variety of inhaled pollens, dusts, and other agents. Because of their importance these disorders are discussed in separate articles. See ASTHMA; HAY FEVER.

常见的过敏。最常见的过敏是花粉热和哮喘，它们是由各种各样吸入的花粉、粉尘以及其它介质引发的。由于它们的重要性，这些紊乱会在单独的文章中讨论。可参阅哮喘；花粉热词条。

Drug Allergies. These allergies may become manifest after ingestion, injection, or contact with the skin. As in the case of foods, most allergic reactions to drugs are immediate.

药物过敏。在摄入、注射或接触皮肤后就会出现这些过敏症。就像食物的情况一样，大多数对药物的过敏反应都是速发性的。

Penicillin is the greatest single cause of drug hypersensitivity. The most common symptom is a diffuse rash, although anaphylactic reactions occur in about one in 10,000 persons. Serum sickness occurs occasionally, and contact dermatitis is fairly common after handling the drug or following topical applications. Many other drugs have been implicated in such allergies—including analgesics, sulfonamides, barbiturates, and even some antihistamines—but allergic reactions to drugs other than penicillin probably are rare.

青霉素是药物过敏症最主要的单一原因。大多数常见的症状是一种弥漫性皮疹，尽管过敏反应大约只占人群中的万分之一。偶尔会出现血清病，而且在处理药物或局部应用后接触性皮炎是很常见的。许多其它的药物也与这类过敏有关---包括镇痛药、磺胺类药、巴比妥类药物，甚至一些抗阻胺药---但除了青霉素，其它药物的过敏反应可能极少见。

Food Allergies. Food does not often cause allergic reactions. Food allergies are more common in infant than in older children and adults, probably because the infant’s immature digestive tract permit more ready absorption of offending food molecules.

食物过敏。食物通常不会导致过敏反应。在婴儿中食物过敏比年长一些的孩子和成人更常见，大概是因为婴儿未发育全的消化道允许吸收了更多令人不适的食物分子。

Manifestations of food allergies in adult are usually of the immediate kind, including hives, angioedema, eczema, gastrointestinal disorders, and general systemic reactions of the anaphylactic type. Systemic reactions occur quickly after eating. They are most frequently caused by legumes, nuts, seafoods (especially shellfish), and berries, but carbohydrates, fats, food additives, and contamination by drugs may be implicated. In infant and children, eczema is the prominent manifestation, and the most frequent causative agents include milk, wheat, eggs, fish, and soybean products.

在成人中出现食物过敏通常都是速发性的种类，包括荨麻疹、血管性水肿、湿疹、肠胃紊乱以及过敏型的一般系统反应。在吃东西后会迅速出现系统性的反应。它们通常是由豆类、坚果类、海产品（尤其是贝类海鲜），以及浆果类，但碳水化合物、脂肪、食物添加剂，以及与药物污染物可能也有关联。在婴儿和儿童中，湿疹是最为常见的，最常见的原因介质包括牛奶、小麦、鸡蛋、鱼类以及豆制品。

Food allergies are diagnosed on the basis of the patient’s allergic history together with trial eliminations of suspected food from the patient’s diet. Skin tests and tests for antibodies in serum are less significant, because the hypersensitive reaction may be provoked by breakdown products of the food resulting from digestion, and not by the food itself.

根据患者的过敏史，连同从患者的食谱中检测，消除可疑的食物来诊断食物过敏。皮肤测试和对血清中的抗体进行检测意义不大，因为超敏反应可能是由消化食物的分解物引发的，而不是食物本身造成的。

The management of food allergies is based mainly on avoidance of the offending foods. An antihistamine taken before a meal may be helpful if a food to which one is allergic is to be eaten. Food allergies in children tend to lessen or disappear with age, but the anaphylactic types manifested in adults do not usually improve over time.

对食物过敏的管理主要是避免令人不适的食物。如果哪一种食物吃了会过敏，餐前服用抗阻胺药会有所帮助。儿童中的食物过敏会随年龄的增长减少或消失，但成年人中出现的过敏类型通常不会随时间的改变而改善。

See also IMMUNITY.

也可参阅免疫力词条。

                                          SIDNEY RAFFEL, Stanford University

                                            西德尼·拉费尔，斯坦福大学

 

                                                 2022年4月18日译

（译者注：该词条位列《大美百科全书》1985年版，第一卷，第593页至595页）