澳大利亚John Murtagh 全科病案研究(四十)——一位旅行者得了荨麻疹

John Murtagh (著)，杨 辉(译)

作(译)者单位:3165 澳大利亚维多利亚州，澳大利亚Monash大学

1 病史

2010 年6 月的某一天，一位19 岁的大学生来看病。她说5 天来在下腹部和右侧大腿出现奇痒无比的皮肤肿块。她还说其他方面没有什么不适，而且身体一直很健康。

2 体检

在沿着浅表血管的地方，有规律地分布着4 ～5 群红色斑丘疹样的环状皮疹，局部出现肿胀，并有抓挠过的痕迹。

3 生活经历

病人说她刚刚从美国回来，她是一个背包客，在加利福尼亚州度过了5 周的探险生活。她说她的一个同伴也有类似的症状，在脖子和上臂出现了红色发痒的疹子。

4 提出问题

4.1 问题1 你的初步诊断是什么?

4.2 问题2 你怎样验证你的初步诊断?

4.3 问题3 这种皮肤疾病通常是怎么得的?

5 对问题的解答

5.1 答案1 初步诊断是臭虫(温带臭虫)叮咬所致。典型表现是沿着表皮血管的走向，散在地分布红色的皮肤损害。这种小型的节肢动物往往在病人熟睡的时候，叮咬病人的血管，吸食病人的血液。在临床上，这种臭虫叮咬往往发生在儿童和青少年身上。皮肤损害通常发生在颈部、肩部、上臂、躯干、腿部。

鉴别诊断是跳蚤叮咬造成的皮肤损害。跳蚤叮咬也会造成奇痒的红色斑丘疹样皮疹，不过跳蚤叮咬往往是多发的，并呈现聚集成一群一群的皮肤损害。跳蚤叮咬通常出现在手臂、前臂、腿部和腰部(那些衣服比较贴近皮肤的地方)。

5.2 答案2 如果在居住的地方或睡觉用的物品(如床垫、床单和睡袋)上找到铁锈颜色的昆虫样本，那么就可以确定你的初步诊断。在显微镜下对样本进行观察，如果确实是臭虫，则可以明确诊断。在寻找证据的时候，注意观察可疑物品上是否有红色的斑点，另外要注意检查旅行用的箱子和包。

5.3 答案3 这种臭虫叮咬往往发生在住客频繁往来的宾馆或起居场所，比如酒店、汽车旅馆、避难所、收容所、背包客栈等。有些住客身上带着臭虫，在床上睡过觉，就会把臭虫带到床上用品上。如果你再在这些床单或床垫上睡觉，就可能被叮咬。臭虫的活动规律是白天栖息，晚上活跃。臭虫并不是喜欢肮脏的地方，而是喜欢温暖的地方，也喜欢二氧化碳浓度高的地方。

6 进一步的问题

6.1 问题4 你准备怎么治疗这种皮肤疾病?

6.2 问题5 你怎么从人群健康的角度来对这种疾病进行管理?

7 对问题的解答

7.1 答案4 治疗策略是对症治疗，其中包括:(1)用水或者消毒剂清洗叮咬的地方;(2)使用普通的止痒剂如炉甘石液，通常足以解决问题;(3)大多数病例可以使用皮质类固醇软膏;(4)可以用冰袋缓解皮肤肿胀。

7.2 答案5 要想在社区控制这类疾病，需要保持住所的清洁，进行彻底的清扫和清洗，特别是要注意保持床上用品的清洁。如果有专业的虫害防治服务，最好请他们来清除昆虫。要想彻底清除有害的昆虫，需要在房间的墙壁和家具上喷洒杀虫剂。在清扫清洗和杀虫过程中，要特别留意那些旧家具，昆虫容易在那里隐藏。对于新购买的床垫也要留意，特别是那些用塑料布包裹的新床垫，因为温度适宜，昆虫也喜欢隐藏在那里。

8 目前的流行情况

以前，因臭虫叮咬造成的皮肤损害是很常见的，而且也是个很大的问题。主要原因是环境卫生条件比较差，居住条件比较拥挤。不过，这个问题现在已经很少见了。根据时代杂志报道(2010 年8 月9 日，Vol 176，NO. 6)，臭虫叮咬在某些地方呈现爆发趋势，特别是纽约市。除虫专家忙于应付大量的灭虫订单，要求灭虫的场所经常是电影院、自助洗衣店、宾馆饭店、办公楼等。流行病学专家认为这种臭虫“回潮”归因于日益频繁的国际间旅行。臭虫往往隐匿在旅行者的箱子或提包里，或者藏在旅行者的衣服里，从一个国家“旅游”的另外一个国家。

译者注:关于旅行者的统计:公安部出入境管理局统计，2009 年外国人出入境4 373 万人次，主要国际旅行者来自日本、韩国、俄罗斯、美国、马来西亚、新加坡、越南、菲律宾、缅甸、蒙古等。中国内地居民出入境9 492 万人次，主要前往国家包括中国香港、中国澳门、日本、韩国、越南、中国台湾、美国、俄罗斯、新加坡、泰国等。

关于国内流动人口的统计:中国流动人口发展报告2010指出，2009 年中国流动人口数量达到2.11 亿人。到2050 年流动人口规模可达到3.5 亿人。

关于臭虫:所谓臭虫是异翅目臭虫科昆虫的总称，约有70 多种，以吸食人类和温血动物的血液为生(特别是温带臭虫和热带臭虫)，身体扁而宽，身长4 ～5 毫米，呈红褐色，分泌有特殊气味，怕光，昼伏夜出。在我国，温带臭虫分布较广，但热带臭虫主要分布在长江以南地区。

关于跳蚤:所谓跳蚤是蚤目内各种蚤科昆虫的总称，寄生在哺乳类动物身上，体形小，没有翅膀，常见的跳蚤包括猫蚤、狗蚤、鼠蚤。

1 History

A 19 year old university student presented in June 2010 with a five day history of extremely itchy skin lumps on her lower abdomen and right thigh. She had no other symptoms and claimed to be in good general health. On examination there were several red maculopapular wheals arranged in groups of four or five in an orderly line corresponding to superficial blood vessels. There was local swelling and scratch marks. The patient had just returned from a 5 week back packing adventure of California in the United States of America. She said that one of her travelling companions had also complained of a red itchy rash on her neck and upper arms.

2 Questions

2.1 What is your provisional diagnosis?

2.2 How would you confirm your provisional diagnosis?

2.3 How is this skin disorder usually acquired?

3 Answers

3.1 The provisional diagnosis is bed bug (Cimex lectularius)bites. This is a classical presentation with the red lesions clustered in a line along superficial blood vessels as the little arthropods suck blood from their sleeping victim. Clinically the bites are usually seen in children and teenagers. The lesions are commonly found on the neck，shoulders，upper arms，torso and legs.

The differential diagnosis is flea bites which also present as itchy red maculopapular lumps. However the bites are usually multiple or grouped in clusters，occurring typically on the arms，forearms，leg and waist (where clothing is tight).

3.2 A bed bug infestation can be diagnosed by the identification of rust- coloured specimens collected from the infected residence or sleeping items such as mattresses and sleeping bags. Examination of the specimens under a microscope will definitely identify the bug. In suspected places look for red specks in mattresses and check luggage.

3.3 The infestation is usually acquired by sleeping in places where the bed bugs have been carried by other humans. This is usually in dwellings with a high occupancy turnover such as hotels，motels，hostels，shelters and backpacker accommodation. The bugs hide by day and become active at night. They are attracted to heat and carbon dioxide，not dirt.

4 Further questions

4.1 How would you treat this skin problem?

4.2 How would you manage this problem from a community perspective?

5 Answers of further questions

5.1 The treatment which is symptomatic is as follows:(1)Clean the bites with water and perhaps antiseptic. (2)Apply a simple anti-itch agent such as calamine lotion which may be sufficient.(3)Most cases are treated with corticosteroid ointment. (4)An ice pack will help to relieve swelling.

5.2 To control the problem keep residences clean with thorough washing and cleaning especially of bedding. For infestation it is advisable to call in a licensed pest controller. The control treatment is directed towards applying insecticides to the crevices in walls and furniture. It is important to be careful with used furniture and insist that mattresses are delivered in plastic coverings.

6 The current endemic

In the past bedbug infestation was big problem and largely confined to squalid crowded accommodation but in recent decades the infestation has been sporadic. Now according to time magazine (August 9 2010，Vol 176. NO 6)there are exploding rates of infestation especially in New York. Pest exterminators are struggling to cope with the demand for eradication. This demand includes treating movie theatres，laundromats，hotels and offices. According to epidemiologists global travel is to blame. The bugs tend to travel in baggage and often hide in luggage and clothing.