Otherwise known as "Christmas tree syndrome", more than a third of Brits suffer from an increase in hay fever-like symptoms at this time of year, according to a poll for Prevalin Allergy.
The signs include an itchy nose, watery eyes, chest pains and coughing, and can affect adults, children and even babies.
Now, experts are warning that asthma sufferers should be on high alert as thousands of patients are admitted to hospital every year in December as a result of mould that can grow on Christmas trees.
“Many people don’t realise that mould naturally grows on Christmas trees,” said Dr Andy Whittamore, the in-house GP at Asthma UK.
“This is made worse when people turn their heating on, as the mould grows faster.
“Mould can be a real problem for the 5.4million people with asthma in the UK, causing allergic reactions that can trigger asthma symptoms and, in some cases, life-threatening asthma attacks.”
Whittamore advises that asthma patients take their preventative inhalers as prescribed to minimise risk of Christmas tree syndrome.
Of course, the sensible alternative would be to invest in a fake tree but apparently even these can cause problems for allergy sufferers.
“There’s no escape even if you’ve cheated with an artificial tree as these can harbour dust which may trigger dust allergy reactions,” said airborne allergies expert Max Wiseberg.