Vos décorations de Noël déclenchent-elles des allergies ?

Why are my allergies so bad at Christmas?

You might think that a blocked or runny nose, itchy and watery eyes, sneezing and coughing over the Christmas season are signs that you have a cold. While the common cold has a high circulation rate in winter, these symptoms could also be triggered by your Christmas decorations.

Professor Michael Rudenko, medical director of the London Allergy and Immunology Centre, explains that many people can get unpleasant allergy symptoms around Christmas time.

It's thought that in the UK and USA, around 35% of people have cold or hay-fever-like symptoms at Christmas. In most cases, these are in fact seasonal allergies to the dust mites, mould and pollen that Christmas trees and other decorations bring into our homes.

Allergies occur when our bodies overreact to particular substances, triggering our immune systems to produce antibodies. These antibodies 'fight' the foreign cells by releasing chemical substances, and it is these substances that trigger allergic reactions.

Dusty Christmas decorations

We store our Christmas decorations for most of the year, and over this time they are likely to collect dust. Where there is dust, there are dust mites - tiny creatures with proteins in their droppings that can trigger allergies in some people.

According to Allergy UK, house dust mite allergy is very common, affecting around 12 million of us in Great Britain. No house is completely free of dust mites, but areas that have been allowed to accumulate a lot of dust - for example, stored Christmas decorations - can trigger allergy flare-ups.

Research into dust mite allergy symptoms has found that people sneeze a lot, have runny or blocked-up noses, and in more severe cases feel tired or weak.

Allergies to Christmas trees

They may make us feel festive, but bringing real Christmas trees into the house can occasionally also trigger allergic reactions in some of us. While pine tree allergy - sometimes called Christmas tree syndrome - is unusual, the mould, pollen, and dust that collect in the trees are slightly more common allergen culprits.

As Christmas trees can bring these three types of allergens into the home, there is also a strong connection between Christmas trees and allergic reactions in people with asthma. Trees can trigger asthma attacks where the airways constrict, which causes difficulty breathing and wheezing.

Not everyone who experiences an allergic reaction around Christmas trees has asthma, and likewise not everyone with asthma has a issue with Christmas trees. However, for some asthmatics the mould, pollen, dust, and even the pine smell, can trigger asthma symptoms, according to Asthma UK.

Mould spores

There are significant numbers of people who are allergic to the mould known as Alternaria. Rudenko explains that this mould spore can start growing on a newly installed Christmas tree.

"Alternaria is one of the most important among the allergenic fungi," he says. "It occurs on many plants and other substrates, including foodstuffs and textiles. It is also one of the most common mould spores found in dwelling dust and in condensation on window frames.

"Alternaria is reported to result in allergic rhinitis and asthma in sensitised people."

The mould spores - or 'seeds' - living on Christmas trees travel through the air and we inhale them. The symptoms of mould allergy are very similar to the symptoms of other allergies, such as sneezing, a runny nose, itching, a blocked nose, and dry, cracked skin.

Christmas tree pollen

People who are allergic to pollen experience symptoms of hay fever, which is more commonly described as seasonal allergic rhinitis. Hay fever symptoms usually occur in the spring and summer when tree and weed pollens are active. However, although pollen is inactive in winter, Christmas trees may still contain pollen.

Pollen travels through the air easily, and it can enter our nose, eyes and lungs - in some people, this can trigger an allergic reaction.

Dust mites

It's not just bringing our dusty decorations out of storage that can cause allergy flare-ups. We can also bring in a lot of dust mites on our Christmas trees. Both real and artificial Christmas trees can be covered in dust mites.

Allergy to house dust mites is the main cause of perennial or persistent rhinitis. Unlike hay fever, which can cause similar symptoms in certain seasons due to pollen allergy, this type of rhinitis can be present all year round, because house dust mites are found at every time of year. In fact, people with persistent rhinitis often find their symptoms are worse in winter because they spend more time outside, away from the mites, over the summer.

If you store an artificial tree each year, be sure to wipe it down with a damp cloth to remove dust before you put it up.

How to tell if you have a Christmas tree allergy?

The symptoms of dust mite, mould and pollen allergies are all very similar and it may be difficult to tell what type of allergy you have. The symptoms are much the same to that of a cold or hay fever. This is also true of pine tree allergy symptoms, although being allergic to the tree itself is much rarer.

Christmas scented candles

According to Allergy Easy, around 1 in 5 people report allergic reactions to scented candles. Many candles are made from paraffin wax which is derived from coal, petroleum, or shale oil. When lit, this can release chemicals that are particularly harmful for people with respiratory problems.

Those with asthma can be especially sensitive to fragranced products such as scented candles. A 2018 study found that 64.3% of people with asthma reported having one or more allergic reactions after being exposed to fragranced products.

Tips and treatment for allergies

Rudenko also advises those who suffer badly at Christmas to seek treatment: "There are methods of both symptomatic treatment and, for people with severe symptoms, long-term treatments known as desensitisation and immunotherapy. These can help to keep Christmas the most wonderful time of the year."