A study from Swedish researchers suggests that washing dishes in the dishwasher might increase the chances that a child will develop allergies.   According to the study, results of which appear in Pediatrics, children of parents who said they mostly washed their dishes by hand were significantly less likely to develop eczema. In addition, they were somewhat less likely to develop allergic asthma and hay fever.   The study, which included more than 1000 Swedish children who were 7 and 8 years old...