Allergy in context
There have always been people with allergies, but it’s only in the past 100 years that it has become a serious problem. Since the 1960s asthma has moved from being perceived as a minor problem to a life threatening condition, and cases of people suffering from life-threatening anaphylactic shock after eating peanuts have increased seven times between 1997 and today.
Beyond these clear cut cases, there's a larger, more nebulous group described in popular culture as 'allergic' but with less acute symptoms. Their existence has founded a booming industry in health food shop 'allergy tests' and 'free from' foods in supermarkets.
What's going on - a few very ill people, their numbers swelled by the hypochondriac middle classes? Or an epidemic of allergy, closely linked to developed societies? Professor Mark Jackson is a historian of the condition. His book Allergy (2006) convincingly argues that the changes are real:
'At the start of the twentieth century, when allergy had no name, hay fever was considered to be a rare disease largely confined to the educated classes of the Western World. By the 1930s and '40s approximately 1 in 30 people were suffering from the major manifestations of allergic reactions. In the immediate post-war decades, it was estimated not only that 10 per cent of the population in the modern industrialised world was experiencing symptoms of allergy but also that the prevalence of allergic diseases was rising rapidly in the developing world. By the turn of the millennium 1 in 5 British children was thought to exhibit some form of allergy, and allergic diseases had been identified as a significant threat to global health.'
Mark Jackson, Allergy
What are the causes of allergy?