A study of 5,000 Melbourne based infants revealed that having older siblings and a pet dog that lives in the home, could reduce the likelihood of infants developing egg allergies (Koplin et al, 2012). This is in line with earlier studies demonstrating that exposure to pets within the first 12 months of life can reduce the incidence of allergies later in life (Ownby et al, 2002). This supports the Hygiene Hypothesis which states that a lack of early childhood exposure to microorganisms, parasites and infectious agents, increase's ones susceptibility to automimmune disorders and allergic diseases. Once allergic however, exposure to known allergens such as dust, dustmite, pet dander, pollens and the like becomes a problem in susceptible individuals. Here is how to reduce your exposure to allergens in the home.