澳大利亞John Murtagh 全科病案研究(四十)——一位旅行者得了蕁麻疹

John Murtagh (著)，楊 輝(譯)

作(譯)者單位:3165 澳大利亞維多利亞州，澳大利亞Monash大學

1 病史

2010 年6 月的某一天，一位19 歲的大學生來看病。她說5 天來在下腹部和右側大腿出現(xiàn)奇癢無比的皮膚腫塊。她還說其他方面沒有什么不適，而且身體一直很健康。

2 體檢

在沿著淺表血管的地方，有規(guī)律地分布著4 ～5 群紅色斑丘疹樣的環(huán)狀皮疹，局部出現(xiàn)腫脹，并有抓撓過的痕跡。

3 生活經歷

病人說她剛剛從美國回來，她是一個背包客，在加利福尼亞州度過了5 周的探險生活。她說她的一個同伴也有類似的癥狀，在脖子和上臂出現(xiàn)了紅色發(fā)癢的疹子。

4 提出問題

4.1 問題1 你的初步診斷是什么?

4.2 問題2 你怎樣驗證你的初步診斷?

4.3 問題3 這種皮膚疾病通常是怎么得的?

5 對問題的解答

5.1 答案1 初步診斷是臭蟲(溫帶臭蟲)叮咬所致。典型表現(xiàn)是沿著表皮血管的走向，散在地分布紅色的皮膚損害。這種小型的節(jié)肢動物往往在病人熟睡的時候，叮咬病人的血管，吸食病人的血液。在臨床上，這種臭蟲叮咬往往發(fā)生在兒童和青少年身上。皮膚損害通常發(fā)生在頸部、肩部、上臂、軀干、腿部。

鑒別診斷是跳蚤叮咬造成的皮膚損害。跳蚤叮咬也會造成奇癢的紅色斑丘疹樣皮疹，不過跳蚤叮咬往往是多發(fā)的，并呈現(xiàn)聚集成一群一群的皮膚損害。跳蚤叮咬通常出現(xiàn)在手臂、前臂、腿部和腰部(那些衣服比較貼近皮膚的地方)。

5.2 答案2 如果在居住的地方或睡覺用的物品(如床墊、床單和睡袋)上找到鐵銹顏色的昆蟲樣本，那么就可以確定你的初步診斷。在顯微鏡下對樣本進行觀察，如果確實是臭蟲，則可以明確診斷。在尋找證據的時候，注意觀察可疑物品上是否有紅色的斑點，另外要注意檢查旅行用的箱子和包。

5.3 答案3 這種臭蟲叮咬往往發(fā)生在住客頻繁往來的賓館或起居場所，比如酒店、汽車旅館、避難所、收容所、背包客棧等。有些住客身上帶著臭蟲，在床上睡過覺，就會把臭蟲帶到床上用品上。如果你再在這些床單或床墊上睡覺，就可能被叮咬。臭蟲的活動規(guī)律是白天棲息，晚上活躍。臭蟲并不是喜歡骯臟的地方，而是喜歡溫暖的地方，也喜歡二氧化碳濃度高的地方。

6 進一步的問題

6.1 問題4 你準備怎么治療這種皮膚疾病?

6.2 問題5 你怎么從人群健康的角度來對這種疾病進行管理?

7 對問題的解答

7.1 答案4 治療策略是對癥治療，其中包括:(1)用水或者消毒劑清洗叮咬的地方;(2)使用普通的止癢劑如爐甘石液，通常足以解決問題;(3)大多數(shù)病例可以使用皮質類固醇軟膏;(4)可以用冰袋緩解皮膚腫脹。

7.2 答案5 要想在社區(qū)控制這類疾病，需要保持住所的清潔，進行徹底的清掃和清洗，特別是要注意保持床上用品的清潔。如果有專業(yè)的蟲害防治服務，最好請他們來清除昆蟲。要想徹底清除有害的昆蟲，需要在房間的墻壁和家具上噴灑殺蟲劑。在清掃清洗和殺蟲過程中，要特別留意那些舊家具，昆蟲容易在那里隱藏。對于新購買的床墊也要留意，特別是那些用塑料布包裹的新床墊，因為溫度適宜，昆蟲也喜歡隱藏在那里。

8 目前的流行情況

以前，因臭蟲叮咬造成的皮膚損害是很常見的，而且也是個很大的問題。主要原因是環(huán)境衛(wèi)生條件比較差，居住條件比較擁擠。不過，這個問題現(xiàn)在已經很少見了。根據時代雜志報道(2010 年8 月9 日，Vol 176，NO. 6)，臭蟲叮咬在某些地方呈現(xiàn)爆發(fā)趨勢，特別是紐約市。除蟲專家忙于應付大量的滅蟲訂單，要求滅蟲的場所經常是電影院、自助洗衣店、賓館飯店、辦公樓等。流行病學專家認為這種臭蟲“回潮”歸因于日益頻繁的國際間旅行。臭蟲往往隱匿在旅行者的箱子或提包里，或者藏在旅行者的衣服里，從一個國家“旅游”的另外一個國家。

譯者注:關于旅行者的統(tǒng)計:公安部出入境管理局統(tǒng)計，2009 年外國人出入境4 373 萬人次，主要國際旅行者來自日本、韓國、俄羅斯、美國、馬來西亞、新加坡、越南、菲律賓、緬甸、蒙古等。中國內地居民出入境9 492 萬人次，主要前往國家包括中國香港、中國澳門、日本、韓國、越南、中國臺灣、美國、俄羅斯、新加坡、泰國等。

關于國內流動人口的統(tǒng)計:中國流動人口發(fā)展報告2010指出，2009 年中國流動人口數(shù)量達到2.11 億人。到2050 年流動人口規(guī)模可達到3.5 億人。

關于臭蟲:所謂臭蟲是異翅目臭蟲科昆蟲的總稱，約有70 多種，以吸食人類和溫血動物的血液為生(特別是溫帶臭蟲和熱帶臭蟲)，身體扁而寬，身長4 ～5 毫米，呈紅褐色，分泌有特殊氣味，怕光，晝伏夜出。在我國，溫帶臭蟲分布較廣，但熱帶臭蟲主要分布在長江以南地區(qū)。

關于跳蚤:所謂跳蚤是蚤目內各種蚤科昆蟲的總稱，寄生在哺乳類動物身上，體形小，沒有翅膀，常見的跳蚤包括貓蚤、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.