According to the World Allergy Organization, allergic diseases constitute the most common cause of chronic illness in developed countries. Wherever prevalence studies have been conducted there is evidence of a steady increase in populations suffering from allergies. In fact, it has now been proposed that there is a worldwide epidemic of allergic diseases.
Epidemiological studies carried out in various countries around the world indicate the prevalence of respiratory allergy as 15-30%. According to the World Health Organization, asthma is now a serious public health problem with over 100 million sufferers worldwide.
The World Allergy Organization has also estimated that allergies are affecting an estimated 22% of the world population and could be as high as 45% in some regions. All around the world, allergies are on the increase and even doubling by some statistics, in the last 25 years. In countries like New Zealand, estimates are showing an increase of 50% just in the last ten years.
The costs of allergic conditions are high. Approximately $20 billion is spent globally each year just on allergic rhinitis, which includes medications, time off from work and physician consultations. The cost of allergy drugs alone is estimated to be $8 billion per annum.