It is estimated that over half of Americans between the ages of 6 and 59 would test positive to one or more allergens. About one quarter of these people would be allergic to dust mites, ragweed or cockroaches. Surveys suggest that about ten million Americans are allergic to cats. Two million are allergic to insect stings. The American Academy of Allergy, Asthma and Immunology believes allergies are the sixth leading cause of chronic (i.e. long-term) disease.
The problem is not confined to the U.S. It is estimated that between forty and fifty per cent of children in North America, Western Europe and Australia have some form of allergy. Why is this a problem if you have asthma? The WHO believes 90 per cent of asthma attacks are triggered by allergic reactions.
An allergy starts with the body’s increased sensitivity to something it perceives as a threat. The immune system overreacts to an allergen that for others is an innocent, unthreatening substance. We don’t know why some people become sensitized to an allergen and others do not, but it is believed that people inherit a tendency for allergies, although not to a specific substance.
Some experts...