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 life have lower levels of IgE sensitization and allergic diseases. In other words, squeaky-clean modern life could be a contributing factor, and may indeed be harmful to children. Comment: All the activists who rail about dangers from exposures to compounds considered harmful, may be causing the entire population harm . Remember how infections brought from Europe to North American decimated a number of indigenous populations. We need to reconsider how clean our environment should be and whether too clean is harmful.