Here's another issue which is confusing: does exposure to pets at an early age increase, or decrease, an individual's likelihood of developing allergies?

A new study says having cats at home raise the risk of the allergic sensitisation of children up to the age of two.

The study published by Chih-Mei Chen et al. in the May edition of the distinguished Journal of Allergy and Clinical Immunology did not approve earlier papers, according to which contact with cat allergens during the first few months of a child's life has a protective effect. The team of authors could even show that apart from keeping cats, even just repeated contact with cat hair within or outside the parental household increases the frequency of allergic sensitisation on the basis of the detection of IgE-specific antibodies against cat allergens.

For older children, it doesn't seem to be that significant, though, according to them. Still, the authors emphasize that family history is still the primary factor determining the risks of developing allergies. Thus, those who are already suffer from allergies-- whether it's hay fever, asthma or pet allergies-- should take extra precaution with their children.