“無菌”空間 寶寶愈易過敏？

 10年前SARS襲 港，奪去近300人性命，全城立即提高衛生意識。回望今天，不少市民依舊架起「病毒雷達」，在公眾場合遇上有人打噴嚏或咳嗽，會本能地掩着口鼻彈開數丈 遠。很多爸媽更替寶寶築起「全天候保護罩」，消毒搓手液、口罩、濕紙巾像隨身法寶，避免孩子受病毒入侵。

可是，再多的保護，也不能保證孩子百毒不侵，究竟是爸毒變得愈來愈窮兇極惡？

醫學界中有一「衛生假說」（hygiene hypothesis），我們身體內的免疫系統本來要負責防禦病毒或細菌的入侵，可是現世代的孩子成長環境愈來愈清潔，他們沒有太多機會接觸外來的細菌或 病毒，免疫系統發揮不了保衛的作用，反而誤將馮京當馬涼，向外來的沒害物質進攻，引發過敏。

錯攻無害物質

根據香港過敏協會的資料顯示，香港的過敏症流行病率和其他發達國家一樣，鼻敏感、濕疹、食物過敏和哮喘的病患率都在上升。難道爸媽為孩子阻擋病毒徒勞無功，甚至增加孩子患上過敏症的風險？

 
香港醫學會會長、兒科專科醫生謝鴻興表示，根據統計及觀察所見，愈來愈多小朋友出現敏感症，尤其是在已發展國家，病例遠多於發展中國家，在同一地區，居於城市與鄉村的孩子比較，前者病例亦較多。


香港過敏協會顧問、免疫及過敏病科專科鄔揚源醫生指出，過敏是人體免疫系統對無害外來物質所產生的不正常反應、炎症，就好像類風濕性關節炎是一種自體免疫疾病，患者的免疫系統攻擊身體內的組織及器官。

他 解釋免疫系統的功能是對抗外來病毒、細菌，過去衛生環境較差，人體內易長有寄生蟲及細菌，而免疫系統就是要抑制寄生蟲和細菌，不過當衛生環境日漸改善，人 體接觸到外來的細菌、病毒和寄生蟲亦減少，免疫系統就會對一些本來無害的致敏原，如蛋白、花生、塵蟎、花粉、小麥、黃豆、昆蟲、水產海鮮等出現過敏。他舉 例說從前日本很多人患有肺結核傳染病，後來民眾逐漸關注個人及環境衛生，至70、80年代，日本人染病的比率才大幅減少，但與此同時，患有過敏症的人士較 昔日多。

進食吞口水 細菌即落肚

可見極度衛生的環境未必對孩子的健康最有利，有可能誘發各種過敏症。再者，家長亦沒可 能為孩子打造無菌環境。謝鴻興指出，「剛初生的嬰兒一出生時，腸道處於無菌狀態，但只要他一進食，甚至吞一啖口水，已經吃了一些細菌下肚。不過，這些菌不 一定有害，也可以是益菌」。他又指人體身上存在很多細菌，病毒、細菌可說是無處不在。

多菌環境非壞事

鄔揚源表示，香港人煙稠密，又處於傳染病高危的亞熱帶地區，人們難避免接觸病毒。孩子處於多細菌、病毒的環境中其實並非壞事，因為根據資料顯示，香港出現過敏症的比率，在全球排名屬中間位置，遠低於英、澳等已發展國家。





資料來源: 明報
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。

嬰兒牛奶過敏引致濕疹-嬰兒濕疹與牛奶過敏

Alfred在出世的首三個月用母乳喂哺，約在兩個月大時開始出現濕疹症狀。轉用奶粉後，濕疹情況惡化，到了六個月大時，他的濕疹蔓延至面部、身體、手腳部位。痕癢的濕疹更影響他的情緒，幸好尚未開始進食固體食物，比較容易處理病情。



Alfred可轉用低敏奶粉，排除對牛奶過敏的問題，然後再教導他的父母如何護理他的皮膚，通常會在兩星期內便可痊愈。



不過，當Alfred開始進食固體食物，因他已經對牛奶過敏，最好先試每種新食物兩至三日，觀察他的皮膚情況有否轉變。如情況惡化，便須立刻停食此種食 物，然後做測試確定。待一至二年後再次進行測試，觀察他對牛奶過敏是否已經消失，如是便可再嘗試飲奶。較容易引起過敏的食物有花生、雞蛋、其他果仁和貝殼 類等。







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。

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。