Archive for December, 2009

Christmas allergies

Tuesday, December 22nd, 2009

Although some people have a general aversion to all things Christmas, this is not truly an allergy.  But for those genuinely allergic people, the festive season can be a frankly dangerous period. Unprecedented numbers of children have developed nut, fruit and general food allergies in recent years as the allergy pandemic takes hold of our lives on a scale that outstrips global warming and climate change.  Christmas time is a highly risky period for these people.  Consider the contents of Christmas foods such as cakes, mince pies, puddings, nuts and all those special treats abundantly available during the Festive Season.  No wonder it’s a worrying time for parents and allergy sufferers. Even the traditional Christmas tree may be a hotbed of allergens, distributing pollen, moulds and resin inside the home.  Whilst a synthetic tree may be as problematic for it may contain allergenic chemicals such as formaldehyde and isocyanates.  These chemicals can trigger off asthma, rhinitis, skin allergies and allergic conjunctivitis.

On a more positive note, the traditional Christmas turkey is a particularly low allergy-risk protein and if served together with low allergy-risk vegetables such as rice, sweet potato, cooked carrot, parsnip, beetroot and peas, this can make a particularly suitable Christmas meal for allergy-prone children and their parents. Finish off the festivities with a hypo-allergenic dessert of cooked pears or apricots. The process of cooking foodstuffs tends to reduce the allergy provoking effects on the immune system by slightly changing the molecular structure of the food.  If in doubt about allergy-risk friends and visitors always keep a good supply of antihistamine medication on hand just in case……………. 

www.allergy-clinic.co.uk/food-allegy/food-allergy-guide

Motor traffic air pollution increases allergies

Thursday, December 10th, 2009

In the Cincinnati study into Childhood Allergy and Air Pollution, 624 babies and toddlers of allergic parents were assessed and when exposured to a combination of high levels of indoor allergens (such as bacteria from throat infections, house dust mites and mould spores)  plus traffic air pollution, this increased their risk of developing wheezing and persistent asthma by six fold.  The well-established Hygiene Hypothesis highlights the connection between a sterile home environment in infancy and  the risk of deveoping childhood allergies.  It was the combined effect of exposure to high levels of indoor allergens (endotoxin) together with the motor car diesel exhaust fumes that seemed to be such a potent trigger for wheezing and persistent airway inflammation.  The resultant chronic airway inflammation is also known to retard long-term normal lung development.  While in children exposed to moderate levels of indoor or outdoor allergens, only 11 percent developed asthma and in those exposed to low levels of allergen but high level air pollution, 18 percent developed persistent or chronic asthma.

http://www.newswise.com/articles/view/558806/?sc=mwtn

New technologies in allergy testing

Friday, December 4th, 2009

Even if allergic to the same food, not all people react to the same protein in the food. There a number of potential allergy provoking proteins found in each food.

Cow’s milk allergy sufferers may react to one of five different casein or whey proteins in milk. Hence most casein allergic children react to cheese and goats milk while whey allergic children seem to tolerate these products. Heating of milk lowers the allergy potential of the whey components. This explains why whey allergic children seem to tolerate boiled or UHT long-life cow’s milk.

The five principal allergenic proteins in cow’s milk have now been identified as Bos d 4 (alpha-lactalbumin) and Bos d 5 (beta-lactglobulin) in whey, as well as Bos d 6 (Bovine serum albumin), Bos d 8 (Casein) and Bos d lactoferrin (Bovine lactoferrin)

While in Hens’ egg white, there are four different allergenic proteins. These are Gal d 1 (Ovomucoid), Gal d 2 (Ovalbumin), Gal d 3 (Conalbumin) and Gal d 4 (Lysozyme).  One of these could set off an egg allergic reaction in a sensitised individual.

In Peanut we find 9 different Ara h allergens and in Latex there are 13 different Hev b allergens, all capable of triggering a peanut or latex allergic reaction. The Latex Hev b 8 allergen, also called a Profilin is similar to the allergy provoking Profilin found in apple, banana and many other fruits.

This may seem very complicated, but a new range of allergy tests for these specific components are now available.  The tests are called recombinant allergen components and confirm to which protein in a food the individual will react.  Certain allergy provoking proteins such as Profilin, PR-10 proteins, Tropomyosin and Lipid Transfer Protein (LTP) can occur in unrelated food such as Hazelnut and Apple or Latex and Avocado. For example an unsuspecting Latex allergy sufferer may have an acute allergic reaction when eating Avocado, Banana, Kiwi or Chestnut for the first time.

Once the specific allergen is identified on allergy testing, the person can be advised which other foods may cause an adverse allergic reaction

Ref: Steinman H, Native & recombinant allergen components. Phadia AB 2008, ISBN 91-970475-6-2