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Meet the Christmas Tree

Winter sees an annual peak in colds, influenza, and asthma attacks. The exact reasons for this spike are not known but it is assumed to be created when individuals begin to spend more and more time indoors; unfortunately, this exposes them to the home’s resident viruses, bacteria, house dust, and allergens. It is widely believed that when individuals experience an allergy that occurs over several seasons, it may be due to the presence of house dust, dust mites, mold spores or other fungi in the home.

These allergens are ever-present in our environment. It is estimated that there are more than 1 million fungal species that inhabit our planet; of these, there are more than 100 families that can cause mold allergy. Given the right growth conditions in the home, mold spores become dangerous when they reach critical levels on surfaces and in the air. Our knowledge of critical spore levels is far from extensive, but studies have suggested that allergic response may occur after exposure to trace spore levels; however, during the winter months and depending on the mold type, growth in the home can produce 100 - 3,000 spores per cubic meter.

According to a plethora of news outlets and articles spanning the past few decades, Christmas trees are a ready source of mold, dust, and dust mite populations and these can wreak havoc on sensitive individual’s health and respiratory tract. This has been projected to be an issue for the roughly thirteen (13) percent of the population who are affected by mold allergy.

The term “Christmas Tree Syndrome” was coined in the early 1970’s when researchers found ~7% of allergic individuals had a spike in symptoms when they had a Christmas tree in their home. Subsequent studies reported that mold spores had gone up by more than fivefold during a 14-day period over the holidays, reaching more than 5,000 spores per cubic meter. A more extensive study was published in 2011 suggesting clippings from 28 Christmas trees contained 53 mold species and 70% of these were potentially harmful.

Some people with underlying allergies and/or asthma developed sneezing, wheezing, or transient rashes shortly after introducing Christmas trees into their homes. The trees were found to harbor a variety of molds including the most allergenic ones (Alternaria, Cladosporium, Penicillium, and Aspergillus) as well as airborne pollens from ragweed, grasses, and other trees.

Other symptoms are also associated with exposure to various varieties of Christmas trees. In a subset of the population, sensitized individuals can develop skin rashes to a component of the Christmas tree’s sap. The irritating material in sap is called colophony or rosin, and it produces a rash like that observed from poison ivy, after a day or two of exposure. In addition, other sensitized individuals observe contact dermatitis simply from exposure to pine needles poking their skin.

Here’s what you can do to prevent Christmas tree allergies:

Reducing mold and dust on real trees

Wash down real pine or fir trees with excess water. Not only will this knock off mold, dirt, dead needles, and other passenger material, it will also extend the lifetime of the Christmas tree. If it is preferred to inhibit mold growth, there are several organic copper or bacterial fungicides that can be sprayed on the tree before bringing them inside the home.

Reducing mold and dust on real trees

Even artificial trees can be a surface where mold, dust and mites can grow. For artificial trees, dust both tree and ornaments, and wash off the stand. It may also be beneficial to us a vacuum or leaf blower to dislodge dust.

Cover skin when decorating

Sensitized individuals should wear long sleeves and gloves to avoid needle pricks and sap. It would be ideal for sensitized individuals to change clothes after tree decoration.

Consider a storage upgrade

Cardboard boxes and open bags stuffed with strands of lights allow dust to accumulate. Switch to storage containers to keep out dust mites. Store artificial trees in a temperature-controlled area of the home when not in use to reduce any possible moisture buildup.

If you or a loved one have underlying allergies this Holiday season, consult with your local allergist to discuss if testing may be appropriate. An allergist can offer you the best care suited for your case and will identify the real triggers of your allergies.

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