People with allergies might want to reconsider having a Christmas tree in their homes — it can spur a ten-fold jump in the mould count after two weeks, says a family doctor.

Dr. Peter Lin, who is based in Toronto, says as soon as a tree is cut down, it's dead and allergy-causing mould sets in.

"You bring it back into your home and now you've got some nice warm temperatures, it starts to dry out and the mould becomes air-borne and then people can have allergies to that," he said.

Even artificial trees can cause allergic reactions, he said.

They might be fine for the first year, but after being stored, they can cause problems.

"The artificial tree, we put in the basement where it's damp, and then guess what, you get mould going on that as well. And, you can also have dust."

For people who can't imagine celebrating Christmas without a Christmas tree, Lin suggests getting a real tree as soon as possible after it's been cut.

"Then want you do is bang it on the ground and that gets rid of all the dead needles and gets rid of the mould that might be growing on them as well."

Lin said the tree can also be hosed down, but must be left outside to dry before being moved indoors. Otherwise, it will encourage mould growth.

Once the tree is moved indoors, it shouldn't be kept up for too long and the water source should be kept covered because it could also become a breeding ground for mould.