Before the first description of hay fever in 1870, there was very little awareness of allergic
disease, which is actually similar to the situation in prehygiene villages in Africa today. The
best explanation for the appearance and subsequent increase in hay fever at that time is the
combination of hygiene and increased pollen secondary to changes in agriculture. However,
it is important to remember that the major changes in hygiene in Northern Europe and the
United States were complete by 1920. Asthma in children did not start to increase until 1960 …