Allergies and the hygiene hypothesis.

In an editorial in the Lancet today: The cost of allergic rhinitis in the USA is nothing to be sniffed at. According to a report published last week by the Agency for Healthcare Research Quality, in 2005, Americans spent $11bn on doctors' bills, prescription drugs, and other medical care to relieve allergy symptoms. Although there is no consensus on the reasons for the increased prevalence of allergies, the hygiene hypothesis has solid support. First proposed by David Strachan in the 1980s, this hypothesis suggests that children exposed to poor hygiene and increased infections in early l...