More evidence that animals reduce childhood allergies

The problem with a catchy name is that sometimes it catches on too well. Take the hygiene hypothesis, outlined in 1989 by David Strachan of St George’s, a hospital and medical school in London. It suggests that the rise of allergenic sensitivity observed in rich countries over the course of the 20th century may have been caused by a corresponding decline in childhood infections, and also by a shift from rural to urban living, so that children are no longer routinely exposed to farm animals.