Outgrowing Food Allergies

Most children outgrow cow's milk, egg, soy and wheat allergy, even if they have a history of a severe reaction. About 20% of children with peanut allergy will outgrow it. About 9% of children with tree nut allergy will outgrow it. Your allergist can help you learn when your child might outgrow a food allergy.




Treatment

The best way to treat food allergy is to avoid the foods that trigger your allergy. Although it has been shown that just smelling peanut butter will not cause a reaction, sometimes food allergens can be airborne, especially in steam, and can cause reactions. Boiling or simmering seafood is a particular offender.

Always ask about ingredients when eating at restaurants or when you are eating foods prepared by family or friends.

Carefully read food labels. The United States and some other countries require that eight major food allergens are to be listed in common language, for example, "milk" rather than a scientific or technical term, like "casein."

Carry and know how to use injectable epinephrine and antihistamines to treat emergency reactions. If a reaction occurs, have someone take you to the emergency room, even if symptoms subside. Afterwards, get follow-up care from an allergist.





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

醫學上的Allergy其實應稱為過敏，是免疫系統的反應

我們所說的「敏感」，其實是泛指對任何問題出現不正常反應，有人說吃了味精之後頭痛，這種情況並不是免疫反應，而是一個化學反應，所以不能稱為過敏，醫學 上只能稱之為不正常反應（Adverse Reaction），不算過敏。過敏是因為吸入致敏原而出現一連串反應，最常見的是鼻敏感、哮喘及皮膚濕疹。


香港有三分一人口有鼻敏感，而過敏這個症狀是不會自我痊愈的，就是有曾經患哮喘而痊愈的人，在年紀稍長之後，哮喘又會復發。

哮喘、風疹、食物休克這些過敏症稱為即時過敏反應（Immediate Hypersensitivity），而因為塗搽了致敏的護膚品或化粧品而出現過敏的是遲緩過敏反應（Delayed Hypersensitivity），前者是因為抗體反應所引起，後者則是免疫細胞反應引起，發病時間比較慢。

過敏是一個免疫病症，簡單來說，是身體的免疫系統對外界的物質產生過度的反應。

人體內有一套複雜的免疫系統，功能就是保護我們的身體免受外界物質侵襲，以及排斥外來的細胞或物質。免疫系統可以辨識所有外來物質的好壞，並會製造抗體來 消除這些外來物。若是遇到一些無害的物質，免疫系統就會自動調節去忍耐這種外來物；如果發現這些物質是有害的話，免疫系統就會啟動，攻擊這些有害物質。

但是，當免疫系統對某些外來物質反應過度時，人體所產生的敏感抗體就會一直記憶在體內，當再接觸到同類引致敏感的物質時，便會產生一連串反應，令身體分泌一種組織胺的化學物質，造成過敏反應，而這種對外界物質的過敏性反應便稱為過敏症。





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。

Outgrowing Food Allergies

Most children outgrow cow's milk, egg, soy and wheat allergy, even if they have a history of a severe reaction. About 20% of children with peanut allergy will outgrow it. About 9% of children with tree nut allergy will outgrow it. Your allergist can help you learn when your child might outgrow a food allergy.

 

Treatment
 
The best way to treat food allergy is to avoid the foods that trigger your allergy. Although it has been shown that just smelling peanut butter will not cause a reaction, sometimes food allergens can be airborne, especially in steam, and can cause reactions. Boiling or simmering seafood is a particular offender.

Always ask about ingredients when eating at restaurants or when you are eating foods prepared by family or friends.

Carefully read food labels. The United States and some other countries require that eight major food allergens are to be listed in common language, for example, "milk" rather than a scientific or technical term, like "casein."

Carry and know how to use injectable epinephrine and antihistamines to treat emergency reactions. If a reaction occurs, have someone take you to the emergency room, even if symptoms subside. Afterwards, get follow-up care from an allergist.


 

Reference :  www.allergy.hk

The above information serve as an education purpose only, you are encourage to

consult with your allergist for appropriate diagnosis and treatment

醫學上的Allergy其實應稱為過敏，是免疫系統的反應

我們所說的「敏感」，其實是泛指對任何問題出現不正常反應，有人說吃了味精之後頭痛，這種情況並不是免疫反應，而是一個化學反應，所以不能稱為過敏，醫學 上只能稱之為不正常反應（Adverse Reaction），不算過敏。過敏是因為吸入致敏原而出現一連串反應，最常見的是鼻敏感、哮喘及皮膚濕疹。

香港有三分一人口有鼻敏感，而過敏這個症狀是不會自我痊愈的，就是有曾經患哮喘而痊愈的人，在年紀稍長之後，哮喘又會復發。

哮喘、風疹、食物休克這些過敏症稱為即時過敏反應（Immediate Hypersensitivity），而因為塗搽了致敏的護膚品或化粧品而出現過敏的是遲緩過敏反應（Delayed Hypersensitivity），前者是因為抗體反應所引起，後者則是免疫細胞反應引起，發病時間比較慢。

過敏是一個免疫病症，簡單來說，是身體的免疫系統對外界的物質產生過度的反應。

人體內有一套複雜的免疫系統，功能就是保護我們的身體免受外界物質侵襲，以及排斥外來的細胞或物質。免疫系統可以辨識所有外來物質的好壞，並會製造抗體來 消除這些外來物。若是遇到一些無害的物質，免疫系統就會自動調節去忍耐這種外來物；如果發現這些物質是有害的話，免疫系統就會啟動，攻擊這些有害物質。

但是，當免疫系統對某些外來物質反應過度時，人體所產生的敏感抗體就會一直記憶在體內，當再接觸到同類引致敏感的物質時，便會產生一連串反應，令身體分泌一種組織胺的化學物質，造成過敏反應，而這種對外界物質的過敏性反應便稱為過敏症。





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。

Outgrowing Food Allergies

Most children outgrow cow's milk, egg, soy and wheat allergy, even if they have a history of a severe reaction. About 20% of children with peanut allergy will outgrow it. About 9% of children with tree nut allergy will outgrow it. Your allergist can help you learn when your child might outgrow a food allergy.

 

Treatment
 
The best way to treat food allergy is to avoid the foods that trigger your allergy. Although it has been shown that just smelling peanut butter will not cause a reaction, sometimes food allergens can be airborne, especially in steam, and can cause reactions. Boiling or simmering seafood is a particular offender.

Always ask about ingredients when eating at restaurants or when you are eating foods prepared by family or friends.

Carefully read food labels. The United States and some other countries require that eight major food allergens are to be listed in common language, for example, "milk" rather than a scientific or technical term, like "casein."

Carry and know how to use injectable epinephrine and antihistamines to treat emergency reactions. If a reaction occurs, have someone take you to the emergency room, even if symptoms subside. Afterwards, get follow-up care from an allergist.


 

Reference :  www.allergy.hk

The above information serve as an education purpose only, you are encourage to

consult with your allergist for appropriate diagnosis and treatment

Pet-specific IgG4 levels and the likelihood of symptomatic pet allergy

An increase in allergen-specific IgG4 (sIgG4) level often accompanies successful allergen immunotherapy. Studies have also suggested that chronic exposure to some allergens may lead to increased sIgG4 that may function as “blocking antibodies” and signal a degree of clinical tolerance.


In a recent study published in The Journal of Allergy and Clinical Immunology: In Practice, Burnett and colleagues report on data from 500 teenage participants in a longitudinal birth cohort and describe the association of dog and cat specific IgE (sIgE), sIgG4, and the ratios of sIgG4/sIgE antibodies to self-reported symptoms when in contact with pets. Serum levels of the pet-specific antibodies were compared between symptomatic and asymptomatic teens.

Compared to asymptomatic participants, those symptomatic upon cat exposure had higher cat sIgE, sIgG4, and lower ratios of sIgG4/sIgE. Those symptomatic after dog exposure had higher dog sIgE and lower ratios of sIgG4/sIgE, but similar levels of sIgG4 compared to asymptomatic participants. Higher cat and dog sIgG4/sIgE ratios were associated with a lower likelihood of reporting allergic symptoms. However, measurement of sIgG4 appeared to add little to the current clinical practice of using sIgE alone to determine the likelihood of clinical allergic responses when in contact with pets.

Based on these data, the authors do not recommend the routine measurement of sIgG4 as a useful supplementary test to sIgE during the diagnostic evaluation of potential pet allergy.






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.

Enjoy Your Stay with Allergies and Asthma

Hotel rooms often have a lot of dust mites and molds in carpeting, mattresses and upholstered furniture. Fumes from cleaning products may also cause problems. Ask for a "green" room if available. If you are allergic to dust mites, you may want to bring your own dust-proof, zippered covers.

 

 

If you are sensitive to molds, request a sunny, dry room away from areas near indoor pools. Also, if you have allergies to any animals, ask about the hotel's pet policy, and request a room that has been pet-free.
 
Visiting family and friends in their homes can be risky if you have allergies or asthma. For instance, during the holidays, dust mites on ornaments and decorations, molds on Christmas trees, wet leaves and logs for wood-burning stoves and perfumes from scented candles can all trigger allergy or asthma symptoms.

If you have pet allergies, your trip may be more enjoyable if you avoid staying in the homes of family or friends with pets.

People with food allergies should be careful about eating home-cooked foods that may contain hidden food allergens

Reference information: http://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.

我是不是過敏症患者 (allergy)？

在日常生活中，過敏症(allergy)其實已經周旋於你與我之間。在氣溫和季節性的氣候轉變時，你會有流鼻水、痕癢、打噴嚏，又或是吃完某種食物後，皮膚出現紅腫和痕癢，便證明了你可能患上過敏症。

過敏症是最常見的長期病患，當中包括鼻敏感、皮膚濕疹、哮喘、食物敏感、昆蟲敏感等等，一些平日時常接觸的東西，亦有可能會令你患上過敏症。

 

免疫反應過敏症發生的原因是因為身體對本來無害的物質產生不正常的免疫反應 (immunological response)。

免疫系統的主要功能是辨別有害和無害的物質，並對所有身體以外的物質作出反應。當有害物質如細菌和病毒入侵及破壞身體的組織時，身體便會發出危險訊息，使免疫系統即時辨認及記錄此物質，並於再次接觸時產生免疫反應。

另一方面，在接觸非病毒或細菌性的物質如花粉、塵蟎和食物時，由於它們沒有破壞身體組織，免疫系統在沒有危險訊息的情況便產生忍耐反應（即不會造成任何症狀），即使再次接觸時亦是沒有異樣。

因免疫系統誤認無害物質為有害，如某類食物、塵蟎，花粉等而產生活躍性的免疫反應時，便是過敏性反應。

 

為什麼會出現不正常反應？

遺傳基因

 

遺傳基因直接影響過敏反應，尤以初生嬰兒為甚。初生嬰兒的免疫系統尚 未成熟，忍耐反應亦未能完善。一般而言，嬰兒的免疫系統大概經過６個月才成熟，從某角度看，已達到成年人的免疫系統功能。可是，從近年的研究顯示，患有過 敏症人士的免疫系統在２至３年還不到成熟階段，若此時接觸到抗原便有可能不產生忍耐反應。

環境因素

 

嬰兒成長的初期環境因素相當重要。有研究指出，小孩在成長的初期所接觸的細菌抗原，會直接影響他們的免疫系統發展。接觸愈多的細菌抗原會加速他們的免疫系統成熟，從而增強免疫的忍耐反應。然而，現代社會的衛生環境理想，父母非常關注小朋友的衛生情況而減少了接觸病毒或細菌的機會，令小朋友在成長時的免疫系統沒有刺激，容易導致過敏症。

致敏原

 

顧名思義，是指容易致敏的抗原。患有過敏症遺傳基因的嬰兒，他們接觸到某些抗原會特別容易產生起敏作用，如貓毛、塵蟎、花生等。若嬰兒成長的初期，免疫系統尚未成熟而經常接觸此類致敏原時，便會引起過敏症。

香港免疫及過敏病科 鄔揚源醫生

 


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。

Enjoy Your Stay with Allergies and Asthma

Hotel rooms often have a lot of dust mites and molds in carpeting, mattresses and upholstered furniture. Fumes from cleaning products may also cause problems. Ask for a "green" room if available. If you are allergic to dust mites, you may want to bring your own dust-proof, zippered covers.

 

 

If you are sensitive to molds, request a sunny, dry room away from areas near indoor pools. Also, if you have allergies to any animals, ask about the hotel's pet policy, and request a room that has been pet-free.
 
Visiting family and friends in their homes can be risky if you have allergies or asthma. For instance, during the holidays, dust mites on ornaments and decorations, molds on Christmas trees, wet leaves and logs for wood-burning stoves and perfumes from scented candles can all trigger allergy or asthma symptoms.

If you have pet allergies, your trip may be more enjoyable if you avoid staying in the homes of family or friends with pets.

People with food allergies should be careful about eating home-cooked foods that may contain hidden food allergens

Reference information: http://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.

Peanut allergy treatment

Food allergy is consistently one of the most anxiety-provoking illnesses for patients or their caregivers, especially if the problem is life-threatening. Eating is something we do several times a day, and the fear that danger lurks within every bite can seriously affect one’s mental well-being. Whereas desensitization treatment has been used for the treatment of allergic rhinitis and asthma for many decades, previous attempts to develop vaccines for food allergy have ended in failure. 

In the last two years, several studies of oral peanut desensitization have been published. While the majority of patients could be successfully desensitized, this treatment is limited by the high rate of adverse reactions and the need for close monitoring. 

Sublingual desensitization is a new method of administering desensitization treatment for patients suffering from house dust mite and pollen allergies. Recent studies have shown effectiveness for patients suffering from allergic rhinitis and asthma. The advantages of this form of treatment include convenience and safety. A recent study of sublingual desensitization for peanut allergy shows encouraging results. The study was carried out at Duke University in North Carolina and Massachusetts General Hospital in Boston. Eighteen children were given sublingual drops of a peanut allergen extract or placebo at increasing doses. None of the patients suffered severe adverse reactions, with only oral itching as the most significant side effect. After 12 months of treatment, those who took the extract could tolerate 20 times the amount of peanut given in an oral challenge than those who took placebo. The average amount tolerated was 1700mg, which was equivalent to 6 – 7 peanuts. Presumably, these patients could continue to eat peanuts regularly to maintain their desensitized state thereafter.

We have started to perform sublingual peanut desensitization using the same extract recently and several patients have been successfully desensitized. We are hopeful that this would become a viable alternative for the majority of patients suffering from peanut allergy.

Reference information: http://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.

Pet-specific IgG4 levels and the likelihood of symptomatic pet allergy

An increase in allergen-specific IgG4 (sIgG4) level often accompanies successful allergen immunotherapy. Studies have also suggested that chronic exposure to some allergens may lead to increased sIgG4 that may function as “blocking antibodies” and signal a degree of clinical tolerance.


In a recent study published in The Journal of Allergy and Clinical Immunology: In Practice, Burnett and colleagues report on data from 500 teenage participants in a longitudinal birth cohort and describe the association of dog and cat specific IgE (sIgE), sIgG4, and the ratios of sIgG4/sIgE antibodies to self-reported symptoms when in contact with pets. Serum levels of the pet-specific antibodies were compared between symptomatic and asymptomatic teens.

Compared to asymptomatic participants, those symptomatic upon cat exposure had higher cat sIgE, sIgG4, and lower ratios of sIgG4/sIgE. Those symptomatic after dog exposure had higher dog sIgE and lower ratios of sIgG4/sIgE, but similar levels of sIgG4 compared to asymptomatic participants. Higher cat and dog sIgG4/sIgE ratios were associated with a lower likelihood of reporting allergic symptoms. However, measurement of sIgG4 appeared to add little to the current clinical practice of using sIgE alone to determine the likelihood of clinical allergic responses when in contact with pets.

Based on these data, the authors do not recommend the routine measurement of sIgG4 as a useful supplementary test to sIgE during the diagnostic evaluation of potential pet allergy.

Reference information: www.aaaai.org/ , 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.

Allergy test: Skin Prick Tests

Allergic symptoms can be caused by different immunological mechanisms. The majority of allergic diseases are caused by either the Type I (or immediate-type) hypersensitivity response, or the Type IV (or delayed-type) hypersensitivity response. The type of tests needed to diagnose allergy depends on the type of allergic reaction being investigated.

Immediate-type hypersensitivity reactions are caused by antibodies called IgE produced by the immune system against allergens such as pollens, house dust mites, mold spores, animal dander, insect venom, food or drugs. When you are exposed to these allergens, the IgE attached to allergy cells called mast cells binds to the allergens and trigger the mast cells to release chemical mediators such as histamine. This leads to swelling, itching, redness, congestion and airway constriction within a matter of minutes.
IgE antibodies are involved in causing nasal and ocular allergies, asthma, insect sting allergies and some types of food and drug allergies.
Skin prick tests involve the introduction of a tiny amount of allergens into the surface layer of the skin, where there is a rich source of mast cells. A small swelling surrounded by redness will appear after 15 minutes if there is sensitivity to the allergens. The video above shows how this is done.

Skin prick tests are quick, safe and accurate. A large variety of allergenic extracts are commercially available for testing. However, the skin must be in good condition and the patient must not have taken antihistamines beforehand. Patients with active dermatitis or urticaria (hives) should not be tested because increased skin sensitivity might result in false positive results. 


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.

Egg Allergy and the Flu Vaccine (Part 2)

An allergic reaction involves the immune system or defense system. If you have an allergy to eggs, your immune system identifies eggs as an invader or allergen. Your immune system overreacts by producing antibodies called Immunoglobulin E (IgE). These antibodies travel to cells that release chemicals, causing an allergic reaction.

Studies show that most egg allergic individuals can receive the flu vaccine safely under the care of their allergist.

There are two ways people with confirmed egg allergy can receive the flu vaccine without being skin tested for the vaccine first.

 

1) One way is to receive the vaccine in two parts. You receive 10 percent of the full dose and wait 30 minutes to see if allergic symptoms develop. If symptoms do not develop, the remainder of the dosage is given and another 30 minute observation period is held.

2) Another way is to give the entire vaccine followed by a 30 minute observation period.

Both should be used under the direction of an allergist skilled in administering the vaccine to people with food allergies.

 

Reference information:  www.aaaai.org/

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.

Egg Allergy and the Flu Vaccine (Part 1)

Flu season is here and so is the need to be protected by getting vaccinated. This vaccine contains a very small amount of egg protein, so before giving it health providers ask if you are allergic to eggs. But do you really know if you are allergic to egg? Could you have egg intolerance?

 

Food allergies affect millions of adults and children. On the flip side, many people think they are allergic and unnecessarily avoid certain products.

 

The big difference between a food intolerance and allergy is an allergy can cause a serious or even life-threatening reaction. This is why it is important to know if you have an allergy or intolerance to egg when you receive a flu vaccination. An allergist / immunologist has specialized training to properly diagnose your reaction to eggs or other foods.

 

Food intolerance happens in the digestive system and occurs when you are unable to properly breakdown food. This could be due to enzyme deficiencies, sensitivity to food additives or reactions to naturally occurring chemicals in foods.

 

 

Reference information:  www.aaaai.org/

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.

Outgrowing Food Allergies

Reference information:  http://www.aaaai.org/ , www.allergy.hk


Most children outgrow cow's milk, egg, soy and wheat allergy, even if they have a history of a severe reaction. About 20% of children with peanut allergy will outgrow it. About 9% of children with tree nut allergy will outgrow it. Your allergist can help you learn when your child might outgrow a food allergy.

Treatment
The best way to treat food allergy is to avoid the foods that trigger your allergy. Although it has been shown that just smelling peanut butter will not cause a reaction, sometimes food allergens can be airborne, especially in steam, and can cause reactions. Boiling or simmering seafood is a particular offender.

Always ask about ingredients when eating at restaurants or when you are eating foods prepared by family or friends.

Carefully read food labels. The United States and some other countries require that eight major food allergens are to be listed in common language, for example, "milk" rather than a scientific or technical term, like "casein."

Carry and know how to use injectable epinephrine and antihistamines to treat emergency reactions. If a reaction occurs, have someone take you to the emergency room, even if symptoms subside. Afterwards, get follow-up care from an allergist.


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.

Pollen Allergy

Reference information: http://www.aaaai.org/,

Activities like camping can be fun, but they can also expose you to outdoor pollen as well as to stinging insects like bees, yellow jackets and wasps. If you have these allergies, avoid camping during high pollen seasons, take your medications with you and carry injectable epinephrine to treat reactions to stinging insects. If you have a severe insect-allergic reaction, get immediate emergency medical treatment. 

Walking, leisure biking and hiking are typically good activities for people with asthma or allergies. If you enjoy the mountains and have asthma, be careful if you are thinking of going above 5,000 feet, as oxygen levels decrease.

Cold weather sports such as cross-country skiing and ice hockey are more likely to make symptoms worse. Also, snorkeling is much safer than scuba diving.

An asthma treatment plan can help you keep your symptoms under control so that you can enjoy exercising or sports activities while traveling.

Bon voyage and safe travels!

Healthy Tips

• If your allergies or asthma are causing problems, have a pre-trip physical.

• Pack all medications, a peak flow meter and a copy of your physician's phone number.

• Consider buying travel medical insurance.

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. 

Enjoy Your Stay with Allergies and Asthma

Reference information: http://www.aaaai.org/,

Hotel rooms often have a lot of dust mites and molds in carpeting, mattresses and upholstered furniture. Fumes from cleaning products may also cause problems. Ask for a "green" room if available. If you are allergic to dust mites, you may want to bring your own dust-proof, zippered covers.

If you are sensitive to molds, request a sunny, dry room away from areas near indoor pools. Also, if you have allergies to any animals, ask about the hotel's pet policy, and request a room that has been pet-free.

Visiting family and friends in their homes can be risky if you have allergies or asthma. For instance, during the holidays, dust mites on ornaments and decorations, molds on Christmas trees, wet leaves and logs for wood-burning stoves and perfumes from scented candles can all trigger allergy or asthma symptoms.

If you have pet allergies, your trip may be more enjoyable if you avoid staying in the homes of family or friends with pets.

People with food allergies should be careful about eating home-cooked foods that may contain hidden food allergens.



Reference information:  www.allergy.hk , www.aaaai.org

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.

House dust mite

Reference information: http://www.polleninfo.org

Pollen which appear at unusual times of the annual cycle:

Usually the pollen season starts in spring and ends in late summer / autumn. Some plants however, flower late in the year and release nonetheless considerable amounts of pollen.

Cedars flower in late September / early October and may cause conspicuous yellowish precipitations similar to what we know from pine and spruce in certain years during May.

Ivy pollen becomes airborne in small amounts at about the same time.

different species of the cypress family may flower throughout the year and release some pollen. In the Mediterranean, cypress is sometimes already in December in full flower.

In late autumn one can notice in some years a yellowish dust layer here and there, composed of rust summer spores of Puccinia (black rust or stem rust on wheat).

long - distance pollen transport

During winter time, sand from the Sahara desert is transported by strong winds far north to Europe. We sometimes detect at such occasions very characteristic pollen grains from Ephedra, which flowers in late winter in the Atlas mountains.

In particular in Scandinavia, birch pollen allergic patients must often face surprising hayfever attacks in early spring although no birch is yet flowering far and wide. Long distance transport can deposit lots of birch pollen of southern origin by suitable weather conditions. Ambitious forcast models are under development, combining methods of meteorology, aerobiology and remot satellite sensing.

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.