計算遺傳過敏症的機會率

遺傳基因是過敏症的重要成因，如果父母患有過敏症的病歷，包括鼻敏感、哮喘、皮膚濕疹和食物過敏等，他們的兒女患上過敏症的機會比一般人士高。

患有過敏症的父母	兒女患過敏症的機會率
父或母的其中一方	30%
父母雙方	50% - 60%
父母雙方患上同一過敏症	70%會患上同一過敏症

從以上列表可知，遺傳基因影響對下一代患上過敏症的機會。

預防勝於治療?

過敏症的遺傳因素複雜非常，並非單一基因所能引起的。到目前為止，醫學界尚未有可靠的基因測試方法來預測下一代會否患有過敏症。然而，有研究指標可以幫助我們統計一下過敏症的患病機會，尤以臍帶血研究為例。

臍帶血研究

早前，有科學家研究嬰兒出生時臍帶血內的免疫細胞，發現了高危的過敏症嬰兒，他們體內的某種免疫細胞功能與一般嬰兒不同，而且他們的IgE抗體亦比正常指數高。

最重要的是，當估計嬰兒患上過敏症的機會率時，亦有望能實行適當的措施可以減低未來過敏症發病率上升的風險，所以，預防過敏症便是目前科學研究的一大重點。

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面對面查詢，而不應單倚賴以上提供的資料。

What happens when inhaled steroids are stopped?

Asthma is a common and burdensome problem, with symptoms that may change over time. Taking regular asthma medications, such as inhaled corticosteroids, can reduce symptoms and decrease the risk of asthma attacks. When asthma is stable, providers may discuss stepping down or discontinuing asthma medicines with their patients. Current guidelines suggest that providers consider stopping (or decreasing) asthma medicines after a period of stable asthma (3-12 months), but the evidence to support these recommendations is limited.



In an article recently published in The Journal of Allergy and Clinical Immunology (JACI), Rank et al. identified clinical trials that involved patients who were stable on a low dose of inhaled corticosteroid and were randomized to either continue or stop the inhaled corticosteroid. The authors performed a systematic search to identify potential articles to include for the study and used established research methods to analyze the data. The data from the resulting clinical trials were pooled together to calculate an estimated risk for having an asthma attack after stopping low-dose inhaled corticosteroids.



The authors identified 1,798 articles using a search strategy that was developed with the aid of with an experienced medical librarian. From these, 172 articles were reviewed in more detail and 7 were ultimately found to meet the pre-specified inclusion criteria. The authors found that those who stopped low-dose inhaled corticosteroids had two times higher risk of having an asthma attack in the next six months than those who continued the inhaled corticosteroid. This difference in risk meant that approximately one in six patients with asthma had an attack in the next six months if they continued their treatment with a low-dose inhaled corticosteroid, and one in three patients had an attack if they stopped the low-dose inhaled corticosteroid.




The authors report on the first attempt to pool information from clinical trials about the risks for asthma attacks after stopping low-dose inhaled corticosteroids. While the authors found an increased risk with stopping asthma medicines, they also noted that many people (two out of three) did very well even after stopping their asthma medicines. The findings from this study can serve as a discussion point for patients with stable asthma and their providers as they decide whether to continue or stop their current asthma medicines.

Reference : www.aaaai.org/

The above information serve as an education purpose only, you are encourage to
consult with your allergist for appropriate diagnosis and treatment.

Poor asthma control may be overestimated in obese children

The prevalence of asthma in children is steadily increasing along with the “obesity epidemic,” leading to speculations about the biological linkages between the two disorders. While a growing body of literature supports the role of obesity in the modulation of asthma severity and control in adults, other studies have shown that obesity is associated with respiratory symptoms independent of asthma and therefore may contribute to asthma misdiagnosis. Because the vast majority of previous studies have focused on adults, the degree to which obesity contributes to asthma control in children is unclear.

In a recent issue of The Journal of Allergy and Clinical Immunology: In Practice, Sah et al. examined the relationship between obesity and asthma control in children 6-17 years of age with physician-diagnosed asthma enrolled in the National Heart, Lung and Blood Institute’s Severe Asthma Research Program at Emory University in Atlanta, Georgia. Children underwent extensive phenotypic characterization consisting of questionnaires, plethysmography, exhaled nitric oxide determination, and venipuncture for Th1/Th2 cytokines. Asthma control was defined according to pre-specified thresholds for lung function and symptom frequency as outlined in the National Asthma Education and Prevention Panel Expert Panel Report-3 (EPR-3).




Of the 269 children included in the analysis, 58 (22%) were overweight and 67 (25%) were obese. No associations between obesity and the composite outcome of asthma control were noted, even after adjusting for the potential confounding effects of age and sex. However, obese children were more likely to report non-specific asthma symptoms such as dyspnea more than twice weekly (adjusted OR 2.65, 95% CI 1.45 – 4.85) and nocturnal awakenings from asthma more than twice monthly (adjusted OR 1.89, 95% CI 1.06 – 3.55). Obese children also had significantly impaired quality of life, greater healthcare utilization and an increased frequency of glucocorticoid bursts, although no differences in pulmonary function were observed aside from lower functional residual capacity. Obese children with uncontrolled asthma further had decreased expression of IL-5, IL-10 and IL-13 but distinct patterns of Th1 versus Th2 polarization were not observed.

These findings suggest that obese children with asthma may experience more non-specific respiratory symptoms such as dyspnea that are associated with increased healthcare utilization and decreased quality of life in the absence of clear Th1 or Th2 polarization. Careful assessment of airway physiology as well as symptoms is warranted in the evaluation of obese children with respiratory symptoms to minimize over-treatment.

Reference : www.aaaai.org/

The above information serve as an education purpose only, you are encourage to
consult with your allergist for appropriate diagnosis and treatment.

常見的過敏藥物 - 抗生素

常見引致過敏的藥物盤尼西林（Penicillins），發病率佔所有抗生素的50%，病徵主要是皮疹和血管性水腫（Angioedema）。

盤尼西林類藥物阿莫西林（Amoxycillin）和氨比西林（Ampicillin）構成所有藥物過敏症個案之15%－20%。然而，病人在服食盤尼西林後長出皮疹，便誤以為是對此藥有過敏反應，但其實皮疹可能是感染引起，跟藥物敏感並無關係。若患者想確定是否對盤尼西林過敏時，可進行皮膚測試。

一般而言，大部份的盤尼西林抗體並不是針對它本身，而是經身體分解後的副產品，所以需利用副產品進行皮膚測試。如測試結果呈陰性反應，然後再試食，肯定沒有過敏症狀後，便可排除對盤尼西林有急性過敏的可能性。倘若患者對盤尼西林有急性過敏反應，但感染不能使用其他抗生素醫治，此時可考慮盤尼西林脫敏治療（Penicillin Desensitization）。

参考资料: 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。

豹紋唇貼 貪靚變爛嘴 (下)

透氣功能差 易發炎生疱疹記者發現該類熱銷的性感唇貼，每張售價二元至六十元不等，有購物網更指產品月銷過百件，並附上多張外國女星使用唇貼的照片作招徠。不過，部分唇貼的安全成疑，除Angela外，有女網民指使用唇貼後，嘴唇紅腫及出現敏感症狀。 為了解此類唇貼產品，記者購入數款每張兩元的唇貼，發現包裝上沒有列明成分及生產商名稱，而唇貼質地與雙面膠紙無異，印有各款圖案。根據唇貼的使用說明，用家要先按照自己的嘴唇形狀裁剪唇貼，然後用水沾濕嘴唇，貼上唇貼，撕去表層貼紙即可，惟未有講解卸除唇貼的方法。 記者將數款唇貼交予皮膚科專科醫生侯鈞翔檢視，侯表示，唇貼有黏力，若產品透氣功能差，容易令嘴唇發炎及長出俗稱唇瘡的疱疹，而唇貼色彩鮮艷，估計可能以色素等化學物質製成，或會刺激嘴唇的分泌腺及神經，甚至引發過敏性皮炎。他指在派對時長時間使用唇貼，傷害會更大，由於唇部炎症反覆性強，康復時間隨時長達數月。 


  忘卸除 瞓醒唇部組織壞死侯直指，過去有測試顯示，用透明膠紙黏住皮膚後撕走，會令皮膚表層水分流失及導致創傷。外國便曾有女士使用唇貼參加派對後忘記卸除，一覺醒來竟發現唇部組織壞死。他稱，嘴唇沒有角質層保護，即使唇貼含有小量的化學物質，嘴唇亦會直接吸收，容易造成敏感，而嚴重的嘴唇敏感更會引發全身過敏反應。侯說，他有不少病人均因接觸過敏原，導致嘴唇發炎。 免疫及過敏病專科醫生鄔揚源則表示，所有塗抹或黏貼在唇部的產品，由於接觸時間長，會產生覆蓋的效果，令唇部吸收力增強，有機會引致唇部過敏，出現嘴乾、嘴裂、嘴唇痕癢及紅腫等過敏反應，嚴重過敏更會令嘴巴灼熱甚至脫皮。鄔指，雖然過敏症狀與天氣乾燥「嘴唇爆坼」的症狀相似，但若唇部出現痕癢或紅腫，即可初步診斷為過敏，市民宜停用所有唇部產品，轉用成分單純的軟膏作恒常護理或向醫生求診。  








 資料來源: orientaldaily.on.cc/ 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。

豹紋唇貼 貪靚變爛嘴 (上)

 











「佢個豹紋嘴好性感！」在今晚的聖誕派對，一張小小的「豹紋唇貼」，定必能令女士艷壓群芳。隨着連串聖誕及新年派對來臨，本港不少店舖及購物網均熱賣各款黏貼式的性感惹火唇貼，售價低至二元有交易，吸引不少愛美女士選購，有網站更指產品月銷逾百件。不過，有貪靚少女使用平價唇貼後，唇嘴潰爛紅腫，有如「孖膶腸」。醫學界人士指，唇貼長時間覆蓋嘴唇，容易令皮膚敏感，輕則會痕癢、脫皮，嚴重更會引致全身過敏，需要長達數月才能痊愈。
 「見佢（唇貼）顏色鮮艷，又有豹紋、斑馬紋咁得意，咪試用囉，每張（唇貼）都係兩蚊，點知會搞到爛嘴！」貪靚的Angela一向愛嘗試美容新產品，為求在聖誕及新年派對中靚絕全場，她早前購買數款性感奪目的「唇貼」試用，竟發現唇貼「易貼難除」「個唇畀張唇貼黐得好實，尤其唇邊嘅皮膚，根本搣唔甩。」最後Angela用肥皂和毛巾不斷擦拭嘴唇，才成功卸除唇貼，惟其粉嫩雙唇弄至又紅又腫，令她十分苦惱。
 對美容甚有心得的女歌手雨僑亦指，最近在派對上見到不少女士使用唇貼，閃石或豹紋款式皆有，惟自言嘴部皮膚易敏感，並擔心會誤將唇貼色彩「吞落肚」，故未有使用，「我見過好多人用，不過自己怕敏感就唔敢用囉！」藝人周秀娜也稱曾考慮使用唇貼，但擔心皮膚敏感紅腫，飲水時不方便，最終打消念頭。(續) 








資料來源: orientaldaily.on.cc/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/, www.djreprints.com

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, www.djreprints.com

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.