ABSTRACT
Although case reports of allergic reactions go back to the Pharaohs, the rise of allergic disease to become one of the common diseases of mankind has occurred over the last 150 yr. It is argued here that the rise has related not only to changes in exposure to allergens but equally to changes in the way that we choose to live. We recognize three main phases of the increase:
1) Hay fever fi rst became well recognized during the last 30 yr of the 19th century and continued to increase through the fi rst half of the 20th century.
