猫特应性综合征的临床症状和诊断:正确诊断的详细指南（FASS系列2 ...

王帆

Clinical signs and diagnosis of feline atopic syndrome: detailed guidelines for a correct diagnosis

猫特应性综合征的临床症状和诊断:正确诊断的详细指南（下）

Domenico Santoro* , Cherie M. Pucheu-Haston† , Christine Prost‡, Ralf S. Mueller§ and Hilary Jackson

 

翻译：王帆

Specific differential diagnoses to consider and eliminate to ensure a correct diagnosis of FASS

为了正确诊断FASS需要考虑和排除的具体的鉴别诊断

Because of the incredible variability in the clinical presentation of FASS, many differential diagnoses should be considered when approaching a cat with potential FASS (Table 4). Many other cutaneous and noncutaneous diseases also may present with encrusted papules, alopecia, head/neck pruritus and cutaneous eroded plaques.

由于FASS的临床表现相当多变，在接触有潜在FASS的猫时，应考虑许多鉴别诊断(表4)。许多其他皮肤和非皮肤疾病也可能出现包覆结痂性丘疹、脱毛、头颈部瘙痒和皮肤糜烂斑块。

 

Ectoparasitoses

外寄生虫病

In addition to fleas, cats also may harbour other ectoparasites that can cause pruritus and/or dermatitis, and these parasites must be identified or ruled out before embarking upon a workup for allergic skin disease. These include lice, Demodex mites (especially D. gatoi), Notoedres, Cheyletiella, Otodectes, Trombiculid mites (chiggers; Neotrombicula/Eutrombicula, and Walbachia) and Lynxacarus. Although all of these mites can affect almost any area of the body, some tend to favour particular body areas, which may assist the practitioner in formulating a list of differential diagnoses. Notoedres, Otodectes and Trombiculid mites tend to be associated with clinical signs localised on the face, head and ears/pinnae.Cheyletiella and Lynxacarus are more likely to affect the dorsum and (in the case of Lynxacarus) perineum, caudolateral thighs and tail base.

除了跳蚤，猫也可能有其他外寄生虫会导致瘙痒和/或皮肤病，在开始对过敏性皮肤病进行检查之前，必须识别或排除这些寄生虫。其中包括虱子、蠕形螨(尤其是戈托伊蠕形螨)、疥螨、姬螯螨、耳螨、恙螨(秋恙螨;新恙螨/真恙螨和Walbachia)和毛螨。虽然所有这些螨虫几乎机体任何区域都可患病，但有些倾向于机体特殊部位发病，这可能会帮助医生制定鉴别诊断列表。疥螨、耳螨和恙螨往往与面部、头部和耳朵/耳廓的临床症状有关。姬螯螨和毛螨更容易影响背部和会阴、大腿尾外侧和尾部。

 

Diagnostic tests which may prove useful in identifying these mites include superficial skin scrapings (D. gatoi, Notoedres, Cheyletiella, ectopic Otodectes and trombiculid mites), deep skin scrapings (D. cati), direct examination of epilated hairs (D. gatoi, Lynxacarus, and the asyet-unnamed third species of feline Demodex mite), collection and examination of surface debris (Cheyletiella and ectopic Otodectes), acetate tape impressions of affected skin (Notoedres, D. gatoi, ectopic Otodectes, Cheyletiella and trombiculid mites), ear swabbings or collection of material using Volkmann curettes (Otodectes and D. cati), and direct examination of the affected area using a magnifying lens or otoscope (Otodectes, Trombiculid mites and Cheyletiella). Faecal examination is occasionally useful for identification of mites. Because many of these mites are contagious to other cats, sampling in-contact animals (which if asymptomatic may be less prone to dislodging/ingesting the mites on their own) may be useful.Finally, for mites that are very difficult to find (especially D. gatoi), symptomatic therapy and post-treatment observation may be required.

证明螨虫存在的诊断性检查很有意义，包括皮肤浅刮(戈托伊蠕形螨、疥螨、 姬螯螨、耳道外耳螨和恙螨)，皮肤深刮(猫蠕形螨)，毛发镜检(戈托伊蠕形螨、毛螨和尚未命名的第三种猫蠕形螨)，收集和检查皮肤碎片(姬螯螨和耳道外耳螨)，皮肤病变处醋酸胶带粘贴(疥螨、戈托伊蠕形螨、耳道外耳螨、姬螯螨和恙螨），用耳拭子或Volkmann刮勺采样(耳螨和猫蠕形螨)，用放大镜或耳镜直接检查病变处(耳螨、恙螨和姬螯螨)。粪便检查有时对螨虫的鉴定有用。因为许多这些螨虫会传染给其他猫，对有接触动物进行采样(如果没有症状，可能不太容易脱落/吃自己的螨虫)可能是有用的。最后，对于很难找到的螨虫(尤其是戈托伊蠕形螨)，可能需要对症治疗和治疗后观察。

 

Flea allergy dermatitis

跳蚤过敏性皮肤炎

One of the most important differentials for FASS is flea allergy dermatitis (FAD). The prevalence of fleas (and associated allergies) varies between different geographical areas. For example, fleas tend to flourish in hot, humid climates, and do less well in arid areas or at high altitudes. The most common flea parasitising cats worldwide is Ctenocephalides felis subsp. felis, although other flea genera also may be present in some areas.

FASS最重要的鉴别诊断之一是跳蚤过敏性皮炎(FAD)。跳蚤(以及相关过敏症)的发病率在不同的地理区域有所不同。例如，跳蚤倾向于在炎热潮湿的气候中繁殖，而在干旱地区或高海拔地区则较少。世界上最常见的寄生猫的跳蚤是猫栉头蚤亚属猫属，但一些地区也可能出现其他跳蚤属。

 

The true prevalence of flea infestation and FAD is difficult to ascertain in cats, as many cases are identified and treated at the general practitioner level. Indeed, in one large single-centre retrospective study of 1,407 cats with dermatological disease, flea infestation was identified in only 7.0% (99 of 1,407) of the total feline dermatology case population, and FAD was identified in only 4.9% (70 of 1,407) of the cats. By contrast, FAD was identified in 29% of 502 cats in a large multicentre retrospective study.1 Part of the variability may be related to geographical differences in flea distribution. The singlecentre study area referenced above is located in the upper northeastern United States, where long, harsh winters may limit flea numbers. By contrast, the cases evaluated in the multicentre study came from a wide variety of geographical locations including France, Germany, Switzerland, southeastern United States, Belgium, Sweden, Estonia and the UK. Many of these areas have a temperate or even subtropical climate, in which fleas might be expected to flourish.

由于许多病例是在全科医生初诊确诊和治疗的，因此很难确定猫身上跳蚤感染和FAD的真正流行情况。事实上，在对1407只患有皮肤病的猫进行的一项大型单中心回顾性研究中，在所有猫科皮肤病病例中，只有7.0%(1407只猫中有99只)发现了跳蚤感染，只有4.9%(1407只猫中有70只)发现了FAD。相比之下，在一项大型多中心回顾性研究中，502只猫中有29%被确诊为FAD部分差异可能与跳蚤分布的地理差异有关。上面提到的单中心研究区域位于美国上东北部，那里漫长而严酷的冬季可能会限制跳蚤的数量。相比之下，在多中心研究中评估的病例来自不同的地理位置，包括法国、德国、瑞士、美国东南部、比利时、瑞典、爱沙尼亚和英国。这些地区大多是温带甚至亚热带气候，跳蚤可能会在那里大量繁殖。

 

Clinical criteria have not yet been developed specifically for the diagnosis of FAD in cats. By contrast with dogs, in which the signs of flea allergy tend to be very distinctive, FAD in cats may manifest in any of the four major clinical reaction patterns: MD, SIAH, FHDP and EGC. Cats also may demonstrate generalised, localised or focal pruritus, with or without associated excoriation and other signs of self-trauma. Flea allergy also may present in association with other forms of allergic dermatitis. For these reasons, identification and elimination of FAD represents a critical step in the workup of any cat suspected of having FASS.

目前还没有专门针对猫FAD的临床诊断标准。与犬相比，犬的跳蚤过敏症状往往非常独特，猫的FAD可能表现在四个主要的临床反应模式中的任何一个:MD, SIAH, FHDP和EGC。猫也可能表现出全身性、局域性或局灶性瘙痒，有或没有相关的抓痕和其他自我损伤的症状。跳蚤过敏也可能出现在与其他形式的过敏性皮肤病。由于这些原因，识别和排除FAD代表了对任何怀疑有FASS的猫进行检查的关键步骤。

 

Historically, several methods have been proposed for confirming the diagnosis of FAD, including intradermal injection with either whole-body flea extract or extract of flea salivary antigens; serological testing to identify IgE specific for either fleas or flea saliva; evaluation of basophil activation after challenge with flea extracts; and live flea challenge exposures. Of these, live flea challenge most closely mimics the clinical scenario and thus would be expected to be the most “specific” method of supporting a diagnosis of FAD. However, this method requires some skill and infrastructure to be performed successfully, and a live flea challenge would not be practical or ethical in clinical practice.

历史上，已经提出了几种方法来确认FAD的诊断，包括全蚤提取物或蚤唾液抗原提取物皮内注射;通过血清学检测确定跳蚤或跳蚤唾液特异性IgE;蚤提取物对嗜碱性粒细胞活化作用的评价活跳蚤暴露激发。其中，活蚤激发最接近临床情况，因此有望成为支持FAD诊断的最“特异”的方法。然而，这种方法需要一些技巧和基础设施才能成功实施，而活体跳蚤激发在临床实践中既不实用，也不符合伦理。

 

Although these methodologies may still be of use to convince the client in “flea denial”, the recent availability of effective and easily administered flea control agents has rendered most of these procedures obsolete, except perhaps for research purposes. As a result, the diagnosis of FAD is now often made by the institution of total flea control for a period of nine to 12 weeks. Aggressive flea control typically involves the use of multiple agents simultaneously to target both adult and juvenile life stages. This may be accomplished by the addition of an insect growth regulator (typically a juvenile hormone analogue or chitin synthesis inhibitor) to an adulticidal product. Alternatively, some adulticidal products have effects on multiple life stages on their own or may kill quickly enough that the flea dies before eggs can be laid.

虽然这些方法可能仍然有助于说服“否认跳蚤”的客户，但最近有效和易于管理的跳蚤驱虫药的可用性已使大多数这些程序过时，也许除了研究目的。因此，FAD的诊断现在通常由持续9至12周的时间完全进行跳蚤控制。积极的跳蚤控制通常涉及使用多种药剂同时针对成虫和幼虫生命阶段。这可以通过在杀成虫产品中添加昆虫生长调节剂(通常为保幼激素类似物或几丁质合成抑制剂)来完成。另外，一些杀成虫产品本身会对多个生命阶段产生影响，或者可能会在产卵前迅速杀死跳蚤。

 

Effective flea control programmes also should incorporate some degree of environmental flea control. Both indoor and outdoor environments may be treated with insect growth regulators (particularly pyriproxifen, which is stable in ultraviolet light) to decrease the viability of any immature fleas in the environment. Frequent vacuuming may help to remove flea eggs and some larvae.

有效的跳蚤控制规划还应纳入一定程度的环境跳蚤控制。室内和室外环境均可使用昆虫生长调节剂(尤其是在紫外线下稳定的吡丙醚)处理，以降低环境中任何未成熟跳蚤的生存能力。经常吸尘可以帮助清除跳蚤卵和一些幼虫。

 

Common causes of “flea control failure” include failure to treat all in-contact animals (including dogs and small mammals); allowing the patient (or other animals in the household) to roam freely during the treatment trial; washing the patient after the application of some forms of topical flea control products; and failure to address potential other sources of fleas (e.g. continual “seeding” of flea eggs into areas such as sheds and crawl spaces by infested wildlife).

“跳蚤控制失败”的常见原因包括未能治疗所有可接触动物(包括犬和小型哺乳动物);允许患猫(或家中其他动物)在治疗试验期间自由外出;在患病动物洗澡后使用某些形式的外部除蚤产品;以及未能解决潜在的其他跳蚤来源(例如，感染的野生动物不断在棚屋和走廊等区域“传播”跳蚤卵)。

 

The complete resolution of signs generally supports a diagnosis of FAD as a sole entity, although the acaricidal effects of some of the newer flea control agents (e.g. isoxazolines) complicates this interpretation somehow. Partial resolution suggests the presence of one (or more) concurrent causes of pruritus/dermatitis. A complete failure to respond suggests that either the cat is not flea-allergic, or that there is a significant flaw in the flea control regimen.

症状的完全消除通常支持FAD的诊断，但一些较新的除蚤剂(如异恶唑啉)的杀螨作用在某种程度上使这一解释复杂化。部分消退提示瘙痒/皮肤病存在一个(或多个)并发病因。完全无效说明这只猫没有跳蚤过敏，或者在控制跳蚤的方案中存在重大缺陷。

 

Staphylococcal infection and Malassezia overgrowth

葡萄球菌感染和马拉色菌过度增殖

Staphylococcal and Malassezia overgrowth/infection is very common in allergic cats. They generally present with signs varying from erythema to pustules to seborrhoea. Because of the clinical similarity between such infections and some clinical presentations of FASS (head and neck pruritus, eosinophilic plaques, erythema and scaling), it is important to rule out such infections in order to have a better picture of the severity of the allergic disease.

葡萄球菌和马拉色菌过度增殖/感染在过敏症患猫中很常见。他们通常表现为皮肤发红、脓疱、脂溢病等症状。由于这类感染与FASS的一些临床表现(头颈部瘙痒、嗜酸性斑块、皮肤发红和皮屑)具有相似性，因此为了更好地了解这种过敏性疾病的严重程度，排除这类感染是很重要的。

 

The prevalence of superficial pyoderma, secondary to allergies, caused by staphylococci is relatively unknown in cats. However, in a retrospective study 22 of 45 (48.9%) cats harboured staphylococcal organisms on the skin surface.15 That study confirmed that when present, the infections are generally caused by coagulasepositive and coagulase-negative Staphylococcus spp. Among others, S. pseudintermedius and S. aureus are the species most often isolated from healthy cats and cats with skin lesions.Studies in atopic people and dogs have shown an increased adherence and colonisation of Staphylococcus on corneocytes; however, it is not known whether this is the case in cats with FASS. Only three studies have been published evaluating feline Malassezia overgrowth/infection. In one study of 18 allergic cats, Malassezia spp. overgrowth was diagnosed cytologically on most of the cats on more than one cutaneous site: facial skin (61.1%; 11 of 18), ventral neck (33.3%; six of 18), abdomen (33.3%; six of 18), ear canal (22.2%; four of 18), chin (11.1%; two of 18), ear pinnae (11.1%; two of 18), interdigital (5.6%; one of 18) and claw-fold skin (5%; one of 18). This study was followed by a second one comparing the aural microflora of healthy, allergic and systemically ill cats. This showed a significantly higher count of Malassezia organisms and bacteria in the ears of allergic and systemically ill cats as compared with healthy cats. In addition, allergic cats had a significantly higher number of bacteria, not yeast when compared to systemically ill cats. Finally, a much lower prevalence (three of 45 cats; 6.7%) of Malassezia dermatitis was reported in a retrospective study on 45 cats with FASS.

在猫中，由葡萄球菌引起的继发于过敏症的浅表性脓皮病的发病率未知。然而，在一项回顾性研究中，45只猫中有22只(48.9%)在皮肤表面携带葡萄球菌该研究证实，当存在时，感染通常是由凝固酶阳性和凝固酶阴性葡萄球菌引起的。其中，假中间型葡萄球菌和金黄色葡萄球菌是最常从健康猫和有皮肤病变猫上分离出来的种类。对特应性皮炎人和犬的研究表明，葡萄球菌在角质形成细胞上的粘附和定殖增加;然而，目前尚不清楚患有FASS的猫是否也是如此。目前仅发表了三项评估猫科马拉色菌过度增殖/感染的研究。在一项对18只过敏症猫的研究中，在大多数猫在超过一处皮肤部位的细胞学检查上诊断为马拉色菌过度增殖:面部皮肤(61.1%;11/18)、颈腹侧(33.3%;6/18)、腹部(33.3%;6/18)、耳道(22.2%;4/18)、下巴(11.1%;2/18)、耳廓(11.1%;2/18)、指间(5.6%;1/18)和爪褶皮肤(5%;1/18)。本研究接着进行了第二项研究，比较健康猫、过敏症猫和全身性疾病猫的耳道微生物菌群。研究表明，与健康猫相比，过敏正和全身性疾病猫耳道中的马拉色菌微生物和细菌数量明显更高。此外，与患有全身性疾病的猫相比，过敏症猫的细菌数量明显更高，而不是酵母菌。最后，患病率要低得多(45只猫中有3只;一项对45只FASS猫进行的回顾性研究报告了马拉色菌皮炎的发病率(6.7%)。

 

Because of the high variability (6.7–61.1%) in the prevalence of yeast (and potentially bacterial) overgrowth/infections in allergic cats, the performance of otic and skin cytological evaluation is mandatory in cats with FASS to identify the presence of such infections. As in other species, the cytological findings have to be correlated with the clinical picture and history. When such infections are present, they may contribute to pruritus. It is advisable to treat the infected cat with topical and/or systemic antimicrobials before a workup for allergic skin disease to better assess the true severity of the FASS. In addition, the assessment of skin infections is essential to ensure a better management of FASS and optimise the response to anti-inflammatory/antipruritic medications.

由于过敏症猫中酵母菌(可能还有细菌)过度增殖/感染的发病率差异很大(6.7-61.1%)，因此必须对FASS猫进行耳部和皮肤细胞学评估，以确定是否存在此类感染。就像在其他物种，细胞学发现必须与临床表现和病史相关。当这些感染存在时，它们可能导致瘙痒。建议在过敏性皮肤病检查之前用外用和/或全身抗菌剂治疗感染患猫，以更好地评估FASS的真实严重程度。此外，对皮肤感染的评估对于确保更好地管理FASS和优化抗炎/止痒药物的反应至关重要。

 

Diagnosis of FASS

FASS诊断

Because of the great variability in clinical appearance of FASS, attempts have been made to provide a set or sets of criteria to guide the practitioner in making a clinical diagnosis of FASS as have been described for canine atopic dermatitis. However, to date, no equivalent set of criteria has yet been devised for the cat. A large retrospective analysis was unable to demonstrate any clear difference between the clinical appearance of cats with FASS and cats with food allergy, with the exception of a significantly higher prevalence of seborrhoea in cats with FASS. Although facial involvement was more consistently observed in cats with food allergy, this difference was not statistically significant.

由于FASS的临床表现非常多样化，人们试图提供一套或几套标准来指导临床医生对FASS进行临床诊断，就像对犬特应性皮炎所描述的那样。然而，到目前为止，还没有针对猫设计出一套相似的标准。一项大规模的回顾性分析无法证明FASS猫与食物过敏猫的临床外观有任何明显的差异，除了FASS猫的皮脂溢发病率明显更高。虽然在食物过敏的猫中，人们更一致地观察到面部发病，但这种差异在统计上并不显著。

 

Although no criteria have yet been developed to distinguish FASS from feline food allergy, two criteria sets have been developed to help distinguish between cats with nonflea-induced hypersensitivity dermatitis (NFHD; most commonly FASS, food allergy or both) from dermatitis owing to other causes, including flea allergy and infectious causes of pruritus (Table 5). The first set of criteria is intended to help distinguish cases of NFHD from all other common causes of pruritus or dermatitis. The presence of at least five of the provided criteria is moderately sensitive and specific for NFHD. The second set of criteria is to be used if flea allergy has been ruled out. In this case, the presence of at least six of the criteria is both highly sensitive and moderately to highly specific for NFHD. Neither set of criteria is intended to substitute for a thorough search for infectious, parasitic or other forms of pruritus. However, complete exclusion of some differentials (e.g. D. gatoi) may be difficult to achieve. Thus, the use of the clinical criteria can help confirming a diagnosis of FASS. Indeed, if other diseases are excluded and the patient fits one or both sets of criteria, the diagnosis of food allergy or FASS is very likely. In this case, the practitioner may feel reasonably reassured that proceeding with one or more dietary elimination trial(s) to distinguish the two disorders is appropriate.

虽然目前还没有制定出区分FASS和猫食物过敏的标准，但已经制定了两套标准来帮助鉴别非跳蚤性过敏性皮肤病(NFHD;最常见的是FASS、食物过敏或两者兼有)，由其他病因引起的皮肤病，包括跳蚤过敏和瘙痒的感染性病因(表5)。第一组标准旨在帮助将NFHD病例与瘙痒或皮肤病的所有其他常见病因区分开来。所提供的标准中至少满足五项，对NFHD具有中度敏感性和特异性。如果跳蚤过敏已被排除，则使用第二套标准。在这种情况下，至少满足六项标准，对NFHD既具有高度敏感性，又具有中度至高度特异性。这两套标准都不为了取代对感染性、寄生虫性或其他形式的瘙痒的彻底搜索。然而，完全排除其他的鉴别诊断(如戈托伊蠕形螨)可能很难实现。因此，使用临床标准可以帮助确诊FASS。确实，如果排除其他疾病，患猫符合其中一套或两套标准，极有可能诊断为食物过敏或FASS。在这种情况下，医生可能会有理由相信，通过一个或多个食物排查试验来鉴别这两种疾病。

 

Allergen testing and FASS

过敏原检测和FASS

Allergen testing should only be performed once the diagnosis of FASS has been reached by ruling out other disorders. Allergen tests are not diagnostic. Rather, they support a clinical diagnosis of FASS and are used to indicate which allergens may be triggering the disease and should be selected for allergen-specific immunotherapy (ASIT) if this is the preferred treatment. ASIT in cats can be based on either intradermal testing (IDT) or allergenspecific IgE serology (ASIS) testing. Unfortunately, very few studies have critically evaluated IDT and ASIS in cats, and although the former is the preferred method used by clinicians, ASIS is the most commonly used technique by practitioners. This is not only because the cost associated with storage of allergens makes IDT impractical for the general practitioner, but also because IDT results are more difficult to interpret in cats as compared with other species (dog and horse).

过敏原检测应该仅在一旦通过排除其他疾病确诊FASS后进行。过敏原测试不能用于诊断使用。相反，它们支持FASS的临床诊断，并用于表明哪些过敏原可能触发疾病，如果这是更好的治疗方法，应选择过敏原特异性免疫治疗(ASIT)。猫的ASIT可以基于皮内试验(IDT)或过敏原特异性IgE血清学(ASIS)试验。不幸的是，对猫的IDT和ASIS进行了严格的评估的研究很少，虽然皮内试验是专科医生首选的方法，但ASIS是全科医生最常用的技术。这不仅是因为储存用于IDT的过敏原对全科医生来说成本高，而且还因为与其他物种(犬和马)相比，猫的IDT的结果更难以解释。

 

Apart from the technical differences between the two tests, it is worth remembering that an IDT detects the presence of allergen-specific IgE bound to cutaneous mast cells, whereas ASIS assesses the presence of circulating allergen-specific IgE. As in dogs, neither IDT nor ASIS are standardised methodologies and both false positive and false negative reactions may be common. It has been shown that in dogs the incidence of false negative intradermal reactions is approximately 10–30%;such high percentages could derive from testing atopic-like dogs or testing at less appropriate times of the year (e.g. too far away from the peak season or in the peak season) yet such data are not available for cats. Likewise, it is not known whether cross-reactivity between related allergens [e.g. house dust mites (HDM) and storage mites] occurs in cats. Positive reactions must ultimately be interpreted alongside the history and clinical signs. For these reasons, the interpretation of allergen testing can be challenging and a consultation with or a referral to a clinician is recommended.

除了两种检测的技术差异之外，值得记住的是，IDT检测的是与皮肤肥大细胞结合的过敏原特异性IgE的存在，而ASIS评估的是循环中过敏原特异性IgE的存在。与犬一样，IDT和ASIS都不是标准化方法，假阳性和假阴性反应可能都很常见。研究表明，犬的皮内假阴性反应的发生率约为10-30%。如此高的比例可能因为测试了异位样皮炎患犬，或在一年中的不太合适的时间进行测试(例如，远离过敏峰值季节或正处于过敏峰值季节)，但对猫没有这样的数据。同样，目前尚不清楚相关过敏原[如屋尘螨(HDM)和储物螨]是否会在猫上发生交叉反应。阳性反应最终必须与病史和临床症状一起解释。由于这些原因，解读过敏原测试可能是具有难度，建议咨询或转诊给专科医生。

 

Intradermal testing

皮内试验

As in dogs and people, the decision of which allergens to test is based on geographical location and data on the prevalence of allergens in the immediate environment of the patient. The assistance of local referral clinicians, veterinary and medical schools, allergy laboratories, textbooks, local human allergists or weather bureaus as well, in the USA, of the National Allergy Bureau (https:// www.aaaai.org/global/nab-pollen-counts?ipb=1) may be helpful.

就像犬和人一样，检测哪种过敏原的决定是基于地理位置和患猫周围环境中过敏原流行的数据。当地转诊临床医生，兽医和医学院，过敏实验室，教科书，当地人类过敏学家或气象局的协助，以及在美国国家过敏局可能是有帮助的。

 

As in dogs, IDT is still considered the “gold standard” in feline allergy medicine; IDT gives immediate results and is thought to be biologically relevant, yet lacks standardisation. In addition, IDT is considered difficult to perform and to interpret in cats as a consequence of the weak reactions often observed in this species for which there are a number of possible causes. One possibility is the increased stress levels that cats show during a veterinary visit. Stress induces a rise in serum cortisol, which may interfere with the reactivity of the test. To reduce stress and false negative responses, cats should be quickly sedated for IDT. Other possibilities may include low levels of reactive IgE or use of the wrong allergen concentrations. Use of the correct allergen concentration is essential, although the same allergen concentrations used in dogs generally have been used for cats. However, a few feline studies have shown that for ≤15 allergens (grass, weed and tree pollens), the concentrations currently used for dogs would be suboptimal, partially explaining the low reactivity in cats. Likewise, using healthy cats, the optimal concentration of histamine was determined to be 1:50,000 w/v instead of 1:10,000 w/v or 1:100,000 w/v used in dogs.

和犬一样，IDT仍被认为是猫过敏症医学的“金标准”。IDT能立即产生结果，并被认为与生物学相关，但缺乏标准化。此外，IDT被认为很难在猫上进行和解释，因为在这个物种中经常观察到的弱反应有许多可能的原因。一种可能是猫在兽医检查时表现出的应激水平增加。应激导致血清皮质醇升高，这可能会干扰测试的反应性。为了减少应激和假阴性反应，猫应迅速镇静进行IDT。其他可能包括低反应性IgE或使用了错误的过敏原浓度。必须使用正确的过敏原浓度，但在犬上使用的过敏原浓度通常也被用于猫上。然而，一些对猫的研究表明，对于≤15种过敏原(草、杂草和树花粉)，目前用于犬的浓度是次理想的，这部分解释了猫的低反应性。同样，在健康猫上，组胺的最佳浓度被确定为1:50000 w/v，而不是在犬上使用的1:10000 w/v或1:100000 w/v。

 

Because cats typically demonstrate weak (transient, small) reactions to IDT, the use of intravenously injected dye solutions (Evans blue and fluorescein) has been suggested. Fluorescein dye administered intravenously at 5 mg/kg, before or immediately after the IDT, enhances and clarifies the results at 15–20 min postIDT, and reactions can be visualised with the aid of Wood’s lamp examination.

因为猫对IDT的反应通常很弱(短暂的，小的)，所以建议使用静脉注射染料溶液(伊文思蓝和荧光素)。在IDT前或即刻静脉给予荧光素染料5mg /kg，在IDT后15-20分钟使结果增强或变清晰，并可借助伍德灯检查显示反应。

 

As in dogs, intradermal injections are commonly performed on the lateral thorax, after the hair is gently clipped and the injection sites are marked. A volume of 0.05–0.1 mL is injected intradermally and the reactions evaluated after 15–20 min (by Wood’s lamp examination if fluorescein is used). The reactions (diameter, turgidity, erythema and size of the wheal or simply diameter of the fluorescence) are compared to those of the positive (histamine phosphate) and negative (allergen diluent) controls. Conventionally, as in dogs, the histamine reaction is graded as 4 and the saline as 0. Subjective reactions with a score of ≥ 2 are considered positive. If intravenous dye solutions are used, positive reactions will show as blue or fluorescent. In that case, the diameter of the positive reaction is considered to be more important than the intensity.

与犬一样，在轻轻地修剪毛发并标记注射部位后，通常在胸侧进行皮内注射。皮下注射0.05-0.1 mL, 15-20分钟后评估反应(如果使用荧光素，通过伍德灯检查)。与阳性对照(磷酸组胺)和阴性对照(过敏原稀释剂)的反应(直径、肿胀、红斑和风疹的大小或单纯荧光的直径)进行比较。按照惯例，与犬一样，组胺反应为4级，生理盐水为0级。检测反应得分≥2分被认为是阳性。如果使用静脉染料溶液，阳性反应将显示为蓝色或荧光。在这种情况下，阳性反应的直径被认为比强度更重要。

 

Percutaneous prick testing

经皮点刺测试

An alternative to the IDT is the percutaneous prick test (PPT). This technique is substantially different from the IDT; in the IDT, the allergens are injected intradermally, whereas in the PPT the allergens are put on the skin surface, the skin is subsequently punctured using a specific tool or a needle and the allergen is passively absorbed. This method is associated with very low risk of adverse reactions. The PPT is widely used in human allergology to test for allergic rhinitis, eczema, asthma and food allergy.

替代IDT的方法是经皮点刺试验(PPT)。这种技术与IDT有本质上的不同;在IDT中，过敏原是在皮内注射的，而在PPT中，过敏原是放在皮肤表面，然后使用特定的工具或针头刺穿皮肤，然后被动地吸收过敏原。这种方法的不良反应风险非常低。PPT广泛应用于人类过敏症学中，用于过敏性鼻炎、湿疹、哮喘和食物过敏的检测。

 

In small animal dermatology, very few studies have assessed the usefulness of PPT in dogs and cats with environmental allergies. In dogs, the first study99 comparing IDT and PPT showed that IDT was much easier to interpret than PPT, and thus for more than two decades the PPT was abandoned. New tools have been patented to administer the allergens in a more consistent and standardised fashion, and the PPT has been rediscovered first in cats and subsequently in dogs. In particular, reliable controls (6 mg/mL glycerinated histamine and 50% glycerosaline solution) have been identified in cats.

在小动物皮肤科，很少有研究评估PPT对环境过敏的犬和猫的有效性。在犬上，第一项比较IDT和PPT的研究表明，IDT比PPT更容易解释，因此在二十多年间PPT被抛弃。新的工具已经获得专利，以更一致和标准化的方式管理过敏原，PPT首先在猫中被重新发现，随后在犬中。特别是在猫上发现了可靠的对照(6 mg/mL甘油组胺和50%甘油盐水溶液)。

 

In dogs and cats, PPT is administered using allergens at a dilution of 1:20 w/v (i.e. undiluted).Once the patient is sedated, the lateral thorax is clipped and the sites for the “pricks” are marked. Then, a drop (0.05 mL) of the allergen (or control) is applied and introduced into the skin via the prick device. In cats, two devices have been tested, the Duotip-test (Lincoln Diagnostics Inc.; Decatur, IL, USA) and the Greer Pick (Greer Laboratories; Lenoir, NC, USA). These devices have prongs at their end (two for the DuoTip and six for the Greer Pick) that are used to prick the skin surface. The skin reactions are read at 15–20 min. A scoring scale similar to that used for the IDT is used for the PPT. Generally, intravenous dyes are not necessary for the PPT. In a comparative study, the Greer Pick gave greater reactions than did the Duo-Tip.

在犬和猫中，使用过敏原稀释1:20 w/v(即未稀释)给药PPT。一旦患猫被麻醉，就胸侧剃毛并标记出“点刺”的位置。然后，一滴(0.05 mL)过敏原(或对照品)通过针刺装置进入皮肤。在猫上测试了两种设备:Duotip测试和Greer Pick 。这些设备的末端有两个尖刺(DuoTip有两个尖刺，Greer Pick有六个尖刺)，用于刺破皮肤表面。在15-20分钟读取皮肤反应。PPT使用与IDT类似的评分量表。一般情况下，PPT不需要静脉染色。在一项比较研究中，Greer Pick比Duo-Tip反应更强烈。

 

ASIS testing

ASIS检测

Allergen-specific IgE serology testing is used widely in general practice because it offers many advantages over the IDT. In particular, ASIS may not require sedation (reducing the patient risk), is less traumatic (no repeated injections), more convenient (no clipping, less time consuming) and less prone to drug interference with test results (e.g. concurrent anti-inflammatory/antipruritic therapy). However, ASIS only measures circulating allergenspecific IgE and does not take into account cutaneous histaminergic and nonhistaminergic pathways. Test reliability also may be an issue, as positive reactions have been shown in nonallergic healthy cats and specific pathogenfree cats. Unfortunately, overall, few studies have been published on the use of ASIS in cats.

过敏原特异性IgE血清学检测被广泛应用于全科临床，因为它比IDT有很多优势。特别是，ASIS可能不需要镇静(降低患者风险)，创伤更小(无需重复注射)，更方便(无需剃毛，耗时更少)，更不容易药物干扰检测结果(例如同时进行抗炎/止痒治疗)。然而，ASIS只测量循环中的过敏原特异性IgE，并没有考虑皮肤的组胺激活和非组胺激活途径。测试的可靠性也可能是一个问题，因为在没有过敏的健康猫和特定的无病原体猫中已经显示出阳性反应。不幸的是，总的来说，很少有关于ASIS在猫上使用的研究发表。

 

Most techniques use a solid phase anti-IgE enzyme-linked immunosorbent assay (ELISA) to evaluate the amount of circulating allergen-specific IgE. Detection may be performed using either monoclonal (more often) or polyclonal antibodies. As in dogs, one of the assays commercially available utilises a unique recombinant fragment of the extracellular portion of the human high-affinity IgE receptor alpha-subunit (FceRIa).

大多数技术使用固相抗IgE酶联免疫吸附试验(ELISA)来评估循环中过敏原特异性IgE的数量。检测可以使用单克隆(更常见)或多克隆抗体进行。与犬一样，一种市售的检测方法利用了人类高亲和力IgE受体α亚基(FceRIa)细胞外部分的独特重组片段。

 

An alternative or complement to the ELISA assay is offered by a rapid in-clinic immunodot assay (Allercept Escreen 2nd generation, Heska Corp.; Ft Collins, CO, USA).The E-screen assay has been designed for use as screening test to enable the clinician to decide whether running a full allergen test (either ASIS or IDT) is appropriate. The assay simultaneously tests for three groups of allergens (a mixture of individual tree allergens, grass⁄ weed allergens and indoor allergens) as well as a control spot (purified IgE). The Allercept E-screen assay was tested and validated comparing it to a classic ASIS panel in one recent study in which the authors tested 62 feline serum samples (31 from healthy and 31 from atopic cats). In addition, 49 of 62 (18 healthy, 31 atopic) samples also were tested with a full panel ELISA assay and the results compared. The overall agreement between the two assays was 88% with a strong agreement between the two assays when individual allergen groups were compared. However, there was no difference in the number of positive reactions in the healthy and atopic cats using either assay (E-screen: 61.3% versus 51.6%;ELISA: 66.7% versus 64.5%). Although a strong correlation was seen between the two assays, it is important to remember that the E-screen only tests for groups of allergens and does not allow the identification of the individual offending allergens.

一种快速的临床免疫斑点检测被用于替代和补充ELISA试验。E-screen评估被设计用于筛选试验，使临床医生能够决定是否进行全面的过敏原试验(ASIS或IDT)是合适的。该试验同时测试了三组过敏原(单一树木过敏原、草/杂草过敏原和室内过敏原的混合物)以及一个对照点(纯化的IgE)。在最近的一项研究中，作者测试了62份猫血清样本(31份来自健康猫，31份来自特应性疾病猫)，并将Allercept E-screen试验与经典的ASIS小组进行了对比。此外，62个样本中的49个(18个健康，31个特应性疾病)也用全面板ELISA检测并比较结果。两种试验之间的总体一致性为88%，当单一过敏原组进行比较时，两种试验之间的一致性很强。然而，使用这两种方法对健康猫和特应性疾病猫的阳性反应数没有差异(E-screen: 61.3% vs 51.6%;ELISA: 66.7% vs 64.5%)。虽然两种检测方法之间存在很强的相关性，但重要的是要记住，E-screen只检测过敏原套组，不允许识别单一过敏原过敏原。

 

Another study, using 179 pruritic cats (FASS, food allergy, flea allergy, undetermined hypersensitivity dermatitis and nonallergic pruritic cats) and 20 healthy cats, showed a positive correlation between levels of allergenspecific IgE and age, outdoor life style, absence of deworming and absence of flea control measures. The same study reaffirmed the unreliable nature of serology testing in making a diagnosis of FASS because no difference was seen among the different groups of pruritic cats.

另一项研究对179只瘙痒猫(FASS、食物过敏、跳蚤过敏、未确定过敏性皮肤病和非过敏性瘙痒猫)和20只健康猫进行了研究，结果显示过敏源特异性IgE水平与年龄、户外生活方式、是否驱虫和是否采取除蚤措施呈正相关。同样的研究也重申了血清学检测在诊断FASS时的不可靠性，因为在不同组别的瘙痒猫中没有发现差异。

 

A study using an experimental model of feline asthma with known sensitising allergens compared IDT with ASIS offered by two commercial laboratories. The detection of allergen-specific IgE using a liquid phase enzymoimmunometric assay showed unreliable results. However, although the FceRIa-based ELISA test had good specificity, it had lower sensitivity than IDT. This suggests that IDT might be a better screening test yet either can be used to guide selection of allergens for ASIT. It is important to remember that the accuracy of these tests is unknown and response to treatment (ASIT) may be the best measure with which to evaluate their accuracy.

一项使用已知致敏过敏原的猫哮喘实验模型的研究将IDT与两个商业实验室提供的ASIS进行了比较。液相酶免疫测定法检测过敏原特异性IgE结果不可靠。然而，尽管基于FceRIa的ELISA检测具有良好的特异性，但其敏感性低于IDT。这表明，IDT可能是一种更好的筛查试验，但也可以用来指导ASIT过敏原的选择。重要的是要记住，这些测试的准确性是未知的，治疗反应(ASIT)可能是评估其准确性的最佳措施。

 

Allergens implicated in FASS

与FASS有关的过敏原

By contrast with dogs, in which multiple studies have identified HDM as the most common allergen involved in AD, few studies describing the relative frequencies of allergen reactivity have been published on cats. One Australian study of 45 cats diagnosed with FASS showed that strong (≥3) IDT reactions were evident in 63.3% of tested cats (19 of 30 cats). Amongst the reactors, pollens (grass, weed and/or tree) and insects (flea, mosquito, ant, moth, horsefly and housefly) were the most common in 89.5% and 68.4% of cats, respectively. Those were followed by strong reactions to HDM (Dermatophagoides farinae and D. pteronyssinus) and flea in 47.4% and 42% of cats, respectively. Strong reactions to moulds (15.8%), storage mites (5.3%), mixed feathers (5.3%) and grain mill dust (5.3%) were present in a minority of the cats. Most of the cats in the study had multiple positive reactions mainly to pollens and insects.In another study of 20 cats with spontaneous asthma, IDTs were performed in 18 cats with positive results to aeroallergens in 15. The allergens identified were HDM D. farinae (eight of 15) and D. pteronyssinus (four of 15), storage mites Acarus siro (six of 15), Glyciphagus domesticus (four of 15) and Tyrophagus putrescentiae (four of 15), cockroach (two of 15) and pollens (eight of 15). As far as allergens commonly identified via ASIS, one study14 reported the presence of positive reactions in 63.3% (19 of 30) of sera from atopic cats; of those, 23.3% had positive reactions to indoor allergens alone. Although in another study reactivity to HDM was similar in normal and FASS cat groups, 30% of cats had reactions to a combination of indoor allergens, grass/weed and tree. Very few cats had positive reactions to either grass/weed and tree (6.7%) or indoor allergens and grass/ weed combinations (3.4%).

与犬相比，多项研究已确定HDM是与AD有关的最常见的过敏原，但在猫身上发表的描述过敏原反应相对频率的研究却很少。澳大利亚的一项针对45只被诊断为FASS的猫的研究表明，63.3%的被测试猫(30只猫中的19只)有明显的强烈(≥3)IDT反应。其中，花粉(草、杂草和/或树)和昆虫(跳蚤、蚊子、蚂蚁、蛾子、马蝇和家蝇)分别占猫的89.5%和68.4%。其次分别有47.4%和42%的猫对HDM(粉尘螨和翼螨)和跳蚤有强烈反应。少数猫对霉菌(15.8%)、储藏螨(5.3%)、混合羽毛(5.3%)和谷物粉尘(5.3%)有强烈反应。研究中的大多数猫主要对花粉和昆虫有多种阳性反应。在另一项对20只患有自发性哮喘的猫的研究中，对18只猫进行了IDT，其中15只猫对空气过敏原呈阳性结果。鉴定出的致敏原分别为粉螨(15只中8只)、翼螨(15只中4只)、储藏螨(15只中6只)、家养食螨(15只中4只)、腐食酪螨(15只中4只)、蟑螂(15只中2只)和花粉(15只中8只)。据一项研究报道，对于通常通过ASIS识别的过敏原，过敏性猫的血清中有63.3%(19/30)呈阳性反应;其中23.3%对室内过敏原有阳性反应。尽管在另一项研究中，正常猫和FASS猫组对HDM的反应相似，但30%的猫对室内过敏原、草/杂草和树的组合有反应。很少有猫对草/杂草和树木(6.7%)或室内过敏原和草/杂草组合(3.4%)有阳性反应。

 

Do any drugs interfere with IDT, PPT and/or ASIS?

是否有药物干扰IDT, PPT和/或ASIS?

A possible influence of anti-inflammatory medications on the results of allergen tests in cats has been hypothesised based on canine studies.However, such studies have not been undertaken in cats and detailed withdrawal guidelines are not available. Thus, the same guidelines used for dogs105 have been generally adopted for cats; for IDT, the withdrawal time for antihistamines is seven days, 14 days for short-acting oral and topical glucocorticoids, and at least 28 days for long-acting injectable glucocorticoids. Short-term (six weeks or less) ciclosporin does not require withdrawal for IDT. Although very few studies have been published on the effects of anti-inflammatory drugs and ASIS, it is generally thought that the results of ASIS are not influenced by anti-inflammatory drugs. Currently no studies have analysed the influence of drugs on PPT in dogs or cats.

根据对犬的研究，抗炎药物可能对猫的过敏原试验结果产生影响。然而，这样的研究还没有在猫上进行，也没有详细的停药指南。因此，对犬的指导原则也被普遍用于猫。对于IDT，抗组胺药停药时间为7天，短效口服和外用糖皮质激素停药时间为14天，长效注射糖皮质激素停药时间至少为28天。短期(6周或更短)环孢素治疗进行IDT时不需要停药。虽然关于抗炎药和ASIS作用的研究很少发表，但一般认为ASIS的结果不受抗炎药的影响。目前还没有研究分析药物对犬猫PPT的影响。

 

In an experimental model, asthma was induced in 18 cats using Bermuda grass allergen (BGA). Cats (n = 6/ group) were randomised to receive oral GCs (10 mg prednisolone once daily), inhaled GCs (600 μg budesonide once daily) or oral placebo (once daily) for one month. Intradermal testing and serum BGA-specific IgE were measured before, during and after treatment. A two week withdrawal for glucocorticoid therapy (both oral and inhaled) was adequate to restore IDT reactivity.

在实验模型中，采用百慕大草过敏原(BGA)诱导18只猫发生哮喘。猫(n = 6/组)被随机分为口服GCs (10 mg泼尼松龙，每日1次)、吸入GCs (600 μg布地奈德，每日1次)或口服安慰剂(每日1次)，为期1个月。分别于治疗前、治疗中、治疗后进行皮内试验及血清BGA特异性IgE测定。停用糖皮质激素治疗两周(口服和吸入)足以恢复IDT反应。

 

The effects of sedatives on IDT in cats are unknown, too, yet clinicians typically use the same drug selection as is used for dogs.

镇静剂对猫的IDT的影响也是未知的，但临床医生通常使用与犬相同的药物选择。

 

Summary

总结

This review highlights the complexity of the FAS and how this syndrome involves multiple organs including skin, gastrointestinal and respiratory systems. It is essential to remember that contrary to dogs (in which the atopic disease manifests mainly with cutaneous signs), asthma may play an important role in atopic cats, and this is often underestimated by dermatologists and general practitioners. This review emphasises the strong connection between cutaneous, gastrointestinal and respiratory systems in allergic cats. Because of the strong clinical similarities between cats with food allergy and cats with FASS, if perennial clinical signs are present, food allergy has to be excluded via one or more strict food trial(s). In particular, it is worth remembering that in cats, extracutaneous clinical signs can occur in both FASS and food allergy: respiratory signs 8.3% versus 11.5%,ocular signs 4.8% versus 12% and gastrointestinal signs 3.9% versus 18.1%, respectively.

这篇综述强调了FAS的复杂性以及该综合征如何涉及包括皮肤、胃肠道和呼吸系统在内的多个器官。必须记住的是，与犬相反(犬的特应性疾病主要表现为皮肤症状)，哮喘可能在特应性疾病猫中发挥重要作用，这往往被皮肤科医生和全科医生低估。这篇综述强调了过敏症猫的皮肤、胃肠道和呼吸系统之间的紧密联系。由于有食物过敏的猫与有FASS的猫在临床上有很强的相似性，如果存在长期的临床症状，必须通过一个或多个严格的食物试验来排除食物过敏。特别值得记住的是，在猫的FASS和食物过敏中都可能出现外部临床症状:呼吸症状8.3%比11.5%，眼部症状4.8%比12%，胃肠道症状3.9%比18.1%。

 

Likewise, in order to rule out flea allergy dermatitis, it is critical to perform very strict flea control, typically by increasing the frequency of the flea prevention medications for nine to 12 weeks.

同样地，为了排除跳蚤过敏性皮炎，执行非常严格的跳蚤控制是至关重要的，通常通过增加9到12周的跳蚤预防药物的频率。

 

Furthermore, it is important to remember that the diagnosis of FASS is both clinical (compatible history and clinical signs) and by exclusion of diseases with similar clinical features. Because similar clinical signs and reaction patterns characterise several skin diseases in cats, the presence of compatible clinical signs or reaction patterns alone should not justify the diagnosis of FASS.

此外，重要的是要记住，FASS的诊断既要通过临床(兼容的病史和临床症状)，也要通过排除具有相似临床特征的疾病。由于相似的临床症状和反应模式是猫的几种皮肤病的特征，因此仅存在一致的临床症状或反应模式不应成为FASS诊断的理由。

 

Finally, in this review we want to emphasise how little research has been done in cats with allergic conditions and remind the reader that much of what we do and know in feline allergies is extrapolated from dogs and humans. More studies are required in order to better assess the phenotypical variations of FAS and how different clinical manifestations respond to different treatments. This is an absolute prerequisite to enable the design of better tailored treatments.

最后，在这篇综述中，我们想强调的是，关于猫过敏性疾病的研究非常少，并提醒读者，我们在猫过敏方面所做的和所知的大部分都是从犬和人类推断出来的。为了更好地评估FAS的表型变异以及不同的临床表现对不同治疗的反应，需要进行更多的研究。这是一个绝对的先决条件，使设计更好的定制治疗。

 

笨笨