5%港童食物敏感 外出用膳小心

每20名港童就有1人食物敏感，並有增加趨勢，食肆卻毋須在餐牌標示致敏成分，孩子出外用膳隨時無命。



有醫生指逾半數病人都在食肆用餐後發病；有加拿大回流的港童吃了一小口叉燒包，即出現氣喘及嘔吐，才知叉燒包混有奶粉，自此外出用餐都要為女兒自備食物，卻受盡白眼，其母慨歎本港對過敏患童支援不足。

李太育有一名15歲女兒，10多年前由加拿大返港居住，惟女兒對多種食物敏感，故不論於外出進食及求學，均帶來諸多不便。李太稱，女兒對牛奶、雞蛋、魚、冬菇、矮瓜等多種食物敏感，需隨時攜帶「救命針」以防萬一。






叉燒包混奶粉 即打「救命針」

她表示，女兒移居香港數月後一次飲茶，吃了一口叉燒包，即時出現氣喘及嘔吐等過敏反應，才知道「叉燒包原來會加入奶粉製造」。

李太即時帶同女兒到附近醫務所求診，並要求醫護人員為幼女注射自攜的「救命針」，但醫生卻誤打於自己手上，幸而女兒於20分鐘後情況好轉，無性命危險。

李太自此外出進餐都先自備女兒食物，擔心餐廳食物會令女兒過敏，卻受盡白眼：「問餐廳（侍應）可否不加入致敏食物，對方會嫌麻煩，叫我們到別處吃，但加拿大的餐廳卻會理解。」



餐廳嫌患者麻煩 受盡白眼

她慨歎，不但本港餐廳嫌患者麻煩，大部分學校亦無就食物過敏兒童提供足夠支援，令患童家長需左撲右撲才覓得合適學校，而女兒現時就讀的學校因曾有學童食物過敏休克送院，安排護士駐校，處理一旦發生的食物過敏情況。

本港每100名14歲以下兒童當中，就有約5人對至少1種食物有過敏反應。身兼香港過敏協會主席的瑪麗醫院兒童及青少年科副顧問醫生何學工表示，食物過敏最快可於5至8分鐘內奪命，幼童進食後出現風疹、面腫、嚴重咳嗽、喘氣等3、4個過敏症狀，應即時求醫。



個案趨增 最快5至8分鐘奪命

何醫生及免疫及過敏病科專科醫生鄔揚源均指，近年本港食物過敏情況均有增加趨勢。

鄔揚源相信食物過敏案增加是因為公眾對此認知加深所致，而臨床所見整體有逾半個案均是於餐廳進食後出現過敏反應而求醫。他說：「香港食物種類較廣泛，接觸得到的食物、調味料亦較多，（臨床）需要更多時間去找出患者食物過敏的致敏原。」

消委會發言人稱，現時食肆出售的即食食物不受食物標籤監管，不需提供即食食物的成分；又認為連鎖快餐店所用的原材料及製作方法較穩定及容易控制，若要於食肆推行致敏物標籤，可先由連鎖快餐店做起，在餐牌標明致敏成分。

食安中心稱，會密切留意國際上對要求食肆標明食物中是否含有致敏成分的情況，並適時檢討食物標籤的要求。

參考資料: www.hket.com/
以上所提供的資訊僅作為教育及參考用途，如果你有任何醫療問題，
應向自己的過敏病科醫生查詢，而不應單倚賴以上提供的資料。

New Rules for Food Allergies (2)

Blood tests that measure immunoglobulin E (IgE) antibodies are very often misinterpreted, experts say. Having IgE antibodies to specific foods doesn't necessarily mean a person will have an allergic reaction when eating the foods. Skin-prick tests are more predictive, but they, too, measure IgE "sensitization," which may not result in an actual reaction. The report estimates that 50% to 90% of presumed allergies are not, in fact, allergies.

Still, many parents whose children have had a bad reaction to one food are anxious to know if they should avoid other foods, too, so they ask doctors to test many foods and avoid them to be safe. "

We get patients referred to us all the time who have been placed on very restrictive diets. They may be off 10 or 20 foods," says Dr. Sampson. "We go through a full evaluation and it turns out they are allergic to only one or two."

It's especially hard to pinpoint a true food allergy in young children with eczema, since they make IgE antibodies to many foods. "If you did 100 food tests, all 100 would be positive. That's what we see from patients coming in from around the country," says David Fleischer, an assistant professor of pediatrics at National Jewish Health in Denver, which specializes in allergy and respiratory diseases.

In a study published online in the Journal of Pediatrics this fall, a review of 125 children evaluated for food allergies and eczema at National Jewish in 2007 and 2008 found that over 90% of the foods they were avoiding were returned to their diets after food challenges.

The guidelines also recommend against using intradermal tests, in which a potential allergen is introduced deep under the skin, and skin-patch tests, a larger version of skin pricks, to diagnose food allergies. And they note that there is little scientific data to support a long list of other tests for allergy assessments, including hair analysis, facial thermography, which detects heat patterns and histamines in the skin, and immunoglobulin G tests, which purport to measure hypersensitivity to 100 or more foods at a time.

Melinda Beck at HealthJourna

Reference information: www.allergy.hk

The information aims to provide educational purpose only. Anyone reading it should consult physician before considering treatment and should not rely on the information above.

New Rules for Food Allergies (1)

Fewer Children May Be Diagnosed as Doctors Told Not to Rely Solely on Standard

Skin and Blood Tests

Parents who have eliminated foods from their children's diets based on allergy tests alone may find that some are safe to eat after all. The National Institute for Allergy and Infectious Diseases issued the first clinical guidelines for diagnosing and treating food allergies Monday, saying that blood or skin tests aren't sufficient when making a diagnosis.

An allergy should be suspected if someone has a reaction within minutes or hours of eating a food, according to the guidelines. Physicians should then take a detailed medical history, conduct a physical exam and confirm the allergy with a skin-prick test, in which tiny drops of the suspected allergen are pricked into the skin, usually in the forearm, to see if red wheals form. None of those steps is definitive by itself, the recommendations say, which will likely to lead to fewer diagnoses.

For a correct diagnosis, "it takes a combination, and in some cases an oral food challenge," in which patients are exposed to tiny amounts of the suspect food under close medical supervision, says Hugh A. Sampson, director of the Jaffe Food Allergy Institute at Mount Sinai Medical Center in New York and one of the authors.

The guidelines, published this week in the Journal of Allergy and Clinical Immunology, are aimed at resolving wide discrepancies in diagnosing and treating food allergies among allergists, dermatologists, gastroenterologists, pulmonologists and emergency physicians, as well as pediatricians and internists. More than 30 professional organizations, federal agencies and patient groups were involved in the report, which was in the works for two years.


The research company Rand Corp. contributed a review of scientific studies.

Roughly 4% of children under age 18—about three million—reported having food allergies in 2007, an 18% increase from 1997, according to the Centers for Disease Control and Prevention. Milk, eggs, peanuts, wheat, soy, fish and shellfish are the most common culprits, although more than 170 other foods have been reported to cause allergic reactions. Symptoms can range from eczema and hives to asthma, inflammation of the esophagus, diarrhea, vomiting and life-threatening anaphylaxis, in which major body systems quickly shut down.

The prevalence of food allergies has been difficult to gauge because of different standards in diagnosing and a proliferation of tests being marketed to doctors. Some tests have not been scientifically validated, experts say, and some doctors lack the expertise to interpret those that have been. The report did not state that kids were being misdiagnosed, but it did note that erroneous diagnoses could affect their nutritional well-being and quality of life.

Melinda Beck at HealthJournal

Reference information: www.allergy.hk

The information aims to provide educational purpose only. Anyone reading it should consult physician before considering treatment and should not rely on the information above.

如何減低嬰兒患過敏症風險？

 

母親的疑問

很多媽媽都想知道，懷孕期戒口能否減低嬰兒患過敏症的風險？

其實，目前仍未有數據支持母親在懷孕期進食高致敏原食物（如牛奶、雞蛋、花生和海鮮等）會增加嬰兒患過敏症風險的說法；但是在餵哺母乳期間若嬰兒已患有濕疹問題，同時又證實對牛奶或雞蛋等過敏，媽媽若要繼續餵哺母乳便應該盡量減少進食這些食物了。

至於需要用配方的嬰兒，特別是高危嬰兒，最好選用高度水解配方；曾有研究用高度水解配方餵哺初生至四個月的高危嬰兒，相比用牛奶配方，結果發現：

 過敏問題－74% 減少至32%

 濕疹問題－31% 減少至14%

 哮喘問題－37% 減少至13%

 腸胃過敏－20% 減少至5%

高危嬰兒在初生到四至六個月大時餵哺不同配方，日後患過敏症的機會各有不同。

配方	結果
牛奶配方	風險增加
大豆配方	風險增加
低敏配方	風險最低，分高度水解和部份水解。未有過敏症的高危嬰兒可用部份水解配方減低過敏風險
母乳	部份母親或會將自己所吃的食物致敏原經母乳傳給嬰兒，不過在高危嬰兒四至六個月大前完全餵哺母乳，患過敏的風險則大大降低。

 

參考資料: www.allergy.hk 

以上所提供的資訊僅作為教育及參考用途，如果你有任何醫療問題，

應向自己的過敏病科醫生查詢，而不應單倚賴以上提供的資料。

濕疹的藥物治療

消炎治理

類固醇可有效消炎,不過有研究發現,類固醇會令患者的皮膚保護功能惡化,當濕疹病發時,類固醇可消退炎症,但長期使用會導致患者的皮膚保護功能受損。類固醇的其他副作用:皮膚萎縮, 皮膚變薄, 出現血管斑, 反彈性皮膚炎。  

因類固醇藥膏不適宜長期使用,目前市面上有售由抗排斥免疫藥物製造的非類固醇藥膏,亦可達消炎作用,但避免了類固醇的副作用,是較為安全的治療過敏性皮炎藥物。儘管如此,非類固醇藥膏的療效始終不及類固醇,所以只能作預防的角色,當患者的皮炎情況已受到類固醇藥物控制時,便可用非類固醇藥膏作預防性使用。  

口服消炎藥物 

嚴重過敏性皮炎的患者,單獨使用外塗藥物難以控制病情。一般來說,他們的免疫系統已是極度過敏,而血液內的IgE抗體相當高,如局部外塗藥物無效時,須使用口服藥物治療。

參考資料: www.allergy.hk
以上所提供的資訊僅作為教育及參考用途，如果你有任何醫療問題，
應向自己的過敏病科醫生查詢，而不應單倚賴以上提供的資料。

脫敏治療 - 舌下脫敏液

免疫療法是目前能治癒過敏症的治療，針對過敏症的成因從而脫敏。口服脫敏治療，含在舌下 / 脷底，以助患者脫敏。舌下脫敏液是一種包含致敏源的血清，只需在舌底下含服，亦稱為舌下免疫治療。

舌下脫敏口服液內有特定份量的致敏源，有助患者體內逐漸建立免疫力。經過一段時間的免疫治療後，當患者再接觸到同類的致敏源，所產生的過敏反應會大大減弱。在其他國家，特別是歐洲，舌下免疫治療愈來愈普遍。超過50篇安慰劑對照臨床研究文獻已在期刊發表。
舌下脫敏液只需每日服用一次，患者可以安在家中服藥，無需定時到診所覆診。


脫敏治療 - 舌下脫敏液

脫敏治療適合能於幼兒身上。愈來愈多研究證明顯示，及早開始脫敏治療能減低幼兒長大後出現哮喘的機會。脫敏治療對於濕疹、復 發性中耳炎這兩種過敏症患者亦有幫助。部份患異位性皮膚炎而未有接受治療的兒童，將來亦有可能出現哮喘。最重要的是，哮喘的普遍程度幾乎可媲美流行病，而脫敏治療正正能減低過敏兒童的哮喘發病率。

大部份患有過敏或相關疾病的人士使用舌下脫敏液後，症狀得以舒緩。舌下脫敏液對於部份無法不能接受脫敏針特別有效，例如，舌下脫敏液能有效改善患有濕疹的兒童的病情，特別是有潛在致敏源的兒童。研究顯示大部份有過敏或濕疹的兒童，成長後可能會出現哮喘或其它長期病患，所以愈早治療，可以避免出現以上情況。


舌下脫敏液的局限性

現時香港僅提供三類舌下脫敏液，可用於對蟎、猫或狗敏感的患者，其他及多類致敏源的患者仍需要使用脫敏針。




參考資料: www.allergy.hk
以上所提供的資訊僅作為教育及參考用途，如果你有任何醫療問題，
應向自己的過敏病科醫生查詢，而不應單倚賴以上提供的資料。

急性過敏反應

 

 

以美國的一項統計顯示，平均每年約有150宗因食物過敏而死亡的個案，而大部份死者在生前是知道自己患有食物敏感，但延遲使用腎上腺素而導致死亡；換言之，因第一次食物過敏而死亡的個案並不常見。

可是，對於患有嚴重哮喘及年青（特別是12－19歲青年）患有食物過敏的人士便要份外小心；有些病人會把食物過敏誤以為哮喘病發而延遲醫治，又或是年青人輕視食物過敏帶來的嚴重後果而奪去了寶貴生命。

因IgE免疫球蛋白E引起的急性過敏反應，病人會長出蕁麻疹，同時有可能有肚痛、肚瀉、嘔吐、喉嚨腫脹、氣管收窄和血壓驟降等症狀，然而，亦約有20－30%的病人沒有以上症狀，當他們出現食物過敏時會誤以為是哮喘發作，久藥無效而引致性命危險。

 

 

 

參考資料: www.allergy.hk

以上所提供的資訊僅作為教育及參考用途，如果你有任何醫療問題，

應向自己的過敏病科醫生查詢，而不應單倚賴以上提供的資料。

激發式測試

激發式測試是診斷過敏症的基石，它廣範地被過敏病專科醫生使用。
測試範圍包括食物、藥物、吸入性激發和其他激發式測試 (熱、冷、運動等) 。

 

食物測試

皮膚點刺測試和特定IgE血液測試常用於診斷食物過敏。但是，若在兩種測試中出現陽性反應，也不代表病人對那類食物敏感。原因是病人的皮膚或驗血檢測中出現陽性反應，但可能身體內部產生一種名為耐受性的免疫反應，來壓制食物過敏的情況。故患有食物過敏的兒童，長大時產生耐受性免疫反應，但數年內仍會得出陽性檢測結果。另一方面, 皮膚點刺測試或驗血測試出現陰性結果則能確實排除患有立刻性類型的食物過敏；所以，當過敏病專科醫生懷疑病人的皮膚或驗血測試結果不正確，或當患者可能已經排除其食物過敏時，便會使用食物口服測試來證實病人是否對某種食物真正過敏。

開放式口服測試是透過緊密的醫療監督下，簡單地給病人作漸進式的餵食，但是有不少病人會在心理壓力的影響下，使測試結果出現偏差。所以把食物掩藏在一個載體內(如蘋果醬)，會給予患者作單方面矇蔽(試驗者被矇蔽對試驗品的資料)或雙重被矇蔽(觀察員和試驗者皆被矇蔽)的方式與單純載體交替使用，排除心理影響。

藥物測試

皮膚測試只能診斷出幾類藥物過敏，如盤尼西林和胰島素。藥物激發測試會從口腔、皮下或靜脈內注入逐漸增加的藥物含量，所以有時會被使用作證實或排除藥物過敏的方法。屬於對化學製品敏感的食品添加劑過敏，與藥物過敏相似，所以在診斷上亦要作口服激發測試。

吸入性激發測試

哮喘的特徵是可逆轉的支氣管閉塞。由於外在因素引發哮喘症狀屬於間歇性的情況，使診斷更為困難。藥物如仿副交感神經劑(methacholine)或氨基酸，在吸入氣管後可觸發哮喘病人氣管收窄，能有效斷定哮喘和測量氣管敏感程度。其它具體哮喘觸發體，如阿斯匹靈和過敏原也可以作診斷用途。

 

 

參考資料: www.allergy.hk/

以上所提供的資訊僅作為教育及參考用途，如果你有任何醫療問題，

應向自己的過敏病科醫生查詢，而不應單倚賴以上提供的資料。

Challenge Testing (Oral Challenge)

Challenge testing is the gold standard for diagnosing allergy. Challenge tests commonly performed by allergists include food challenge, drug challenge, inhalation challenge and physical challenge (heat, cold, exercise).

Oral Challenge

Skin prick tests and specific IgE blood tests are often used to aid in the diagnosis of food allergies. However, having positive skin tests or specific IgE to foods does not necessarily mean that the patient is allergic to those foods. The reason is because the body can develop an immune response called oral tolerance that suppresses the food allergy while the skin or blood test remains positive. Therefore, young children with food allergies often develop tolerance when they grow older while their test results remain positive for a few more years. On the other hand, negative skin or blood tests can reliably exclude immediate-type food allergy.

Allergists therefore use food challenge to determine whether a patient is allergic to a particular food when there is suspicion that skin or blood test results are incorrect, or when the patient might have outgrown his/her food allergy. An open challenge is performed by simply giving the patient increasing amounts of the food under close medical supervision. However, a significant amount of psychological overlay is sometimes present, which will bias the result of the challenge. Therefore the food is often hidden in a vehicle such as apple sauce and given to the patient in a single-blinded (subject is blinded to the test condition) or double-blinded (both observer and subject blinded) manner, alternating with plain vehicle.

Reference information: www.allergy.hk/

The information aims to provide educational purpose only. Anyone reading it should consult physician before considering treatment and should not rely on the information above.

如何診斷鼻敏感？

當你有打噴嚏、鼻子癢及鼻塞的症狀時，亦不等於患有過敏性鼻炎，最重要的是找出導致這些徵狀的原因。

 

 

當醫生為病人檢查時，通常會發現病人的鼻膜會因血管滲水而腫脹和蒼白，鼻膜表面更不平滑；另外，鼻敏感的分泌是無色、質地較稀（如鼻水）的，而由感染引起的鼻涕則較濃。

 

診斷有法

診斷鼻敏感有2大方法：

嗜酸性粒細胞：

在患者的鼻膜內取出小量細胞，並在顯微鏡下觀察，若發現有敏感性發炎細胞「嗜酸性粒細胞」時，即表示患上過敏性鼻炎。

敏感測試：

皮膚測試是一種檢查患者對某些致敏原的過敏反應方法，從而避免／減低接觸致敏原的風險。

 

 

 

 

 

參考資料: www.allergy.hk

以上所提供的資訊僅作為教育及參考用途，如果你有任何醫療問題，

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