Just when you thought Christmas 2020 couldn't bring any more nasty surprises, doctors are warning people to beware of Christmas Tree Syndrome.

The tip comes as Australians increasingly embrace real Christmas trees over artificial ones. Christmas Tree Syndrome is well documented overseas, with a study by the State University of New York finding that 70% of the moulds found in live Christmas trees trigger some sort of reaction.

Sacred Heart Pediatrician Dr Brandy Boutin told ABC News: "Christmas trees are grown outdoors for several years before they are harvested and brought to a facility and then to our houses. Everything that tree accumulates over the years, you are bringing into your home. A nice warm moist environment and that's where mould likes to grow."

Dr Boutin said Christmas Tree Syndrome can cause severe asthma attacks, fatigue and sinus congestion. 

"Spores are very tiny, you can see them in a microscope. You won't be able to se them on your tree," she said.

Dr Boutin suggests hosing down your live tree before you bring it into the house, as this will help wash off the allergens. You can also try using a leaf blower on it and it's a good idea to keep the tree in your house for less than two weeks.

An air purifier can be helpful and take over-the-counter antihistamines if you need them.

Sydney mother hospitalised over Christmas tree allergy

A Sydney woman, Niki Waldegrave, has told 7NEWS she suffered an allergic reaction to real a Christmas tree that so severe she had to be hospitalised.

“My arms were coming out in hives (and) my face … basically everything went nuts,” she said.

Waldegrave was administered antibiotics and steroids to stem the swelling, which took more than a week to clear up. 

The National Asthma Council’s Adele Taylor told news.com.au that it’s not uncommon for people to have allergic reactions when bringing large trees into their living rooms,

“They will get pollen and other particles on them in the growing process,” she said.

“So when you get them down and bring them into your home, they will still be on the tree.”

If you're prone to allergies it's best to get someone else to carry the tree into the house and hang decorations. 

Taylor said artificial trees also create issues. It's suggested you give your tree a good shake outside before putting it up, unpack decorations outside and vaccum them or wipe them down with a damp cloth.

When it comes to packing them away, use airtight plastic bags and sealed boxes so they’re less likely to collect dust.

© Prevention Australia