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Christmas Tree Syndrome: Festive Decorations Could Leave You Feeling Sick This Holiday

There are some simple precautions to stop allergies from turning you into the Grinch.


Tom Hale


Tom Hale

Senior Journalist

Tom is a writer in London with a Master's degree in Journalism whose editorial work covers anything from health and the environment to technology and archaeology.

Senior Journalist

Edited by Maddy Chapman

Maddy is a Editor and Writer at IFLScience, with a degree in biochemistry from the University of York.

Young woman decorates the Christmas tree with toys. Preparing for the holidays

A single live Christmas tree can host more than 50 species of mold.

Image credit: nikkimeel/

Tis the season to deck the halls in lights, bells, and festive decorations. If you suddenly catch yourself feeling under the weather with a stuffy runny nose and scratchy throat, it might not necessarily be a seasonal cold just in time for the holiday season – there’s a good chance it could be Christmas tree syndrome.

Christmas tree syndrome is the nickname for a condition triggered by exposure to the allergens found on live Christmas trees.


Symptoms are similar to other allergic reactions, but they might also be mistaken for a cold-like illness (or god forbid COVID). This includes a blocked or runny nose, itchy and watery eyes, sneezing, itchy throat, wheezing, and coughing. You might also experience skin-related symptoms, including redness, swelling, and itching

The allergic reaction can be particularly nasty if you have underlying health issues such as asthma. 

“People with asthma may suffer from a flare-up of their symptoms or an attack where the airways constrict, which could cause difficulty breathing and wheezing. However, not everyone who experiences an allergic reaction around Christmas trees has asthma. Similarly, not everyone with asthma will experience an allergic reaction,” Dr Bhavini Shah, a General Practioner at LloydsPharmacy Online Doctor, said in a statement sent to IFLScience.

Christmas trees are absolutely riddled with potential allergens, including pollen, dust mites, and – most significantly – mold. A single Christmas tree can host more than 50 species of mold, all of which produce airborne spores that could potentially anger your immune system.


Research has estimated that levels of airborne mold spores in an apartment increased from 800 spores per cubic meter before the introduction of a live conifer to 5,000 spores per cubic meter after it had been in the home for two weeks. 

“Mould spores can be present on Christmas trees, particularly live trees like pine, fir, or spruce. Trees are grown outdoors where they can pick up mold spores from the surrounding environment, especially in damp or humid areas,” Dr Shah continued.

“When these trees are brought indoors and placed in a warm and dry environment, any existing spores can become airborne, potentially causing allergy symptoms,” she added.

Fortunately, there are some easy precautions you can take to ensure your Christmas decorations don’t leave you feeling like the Grinch.


“If you have asthma or a real tree has triggered allergies before, you might want to get an artificial tree rather than a real one. If you do opt for a real one, you should shake down the tree to remove as much dust, mold, and pollen as possible before bringing it into the house. Keeping it in the coolest part of the house will avoid any mold spores multiplying,” Dr Shah concluded.


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