Christmas Trees May Trigger Mold Allergies

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Nov. 16 (HealthDay News) -- While bringing home a live Christmas

tree marks the beginning of the holiday season for many, the mold

that thrives on its branches can trigger weeks of suffering for

some, a new study shows.

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from Health Connecticut researchers have found that the mold count

from a live Christmas tree rose to five times the normal level two

weeks after the tree was brought indoors, and that can prove

problematic for people with mold allergies. Their research was

presented this week at the American College of Allergy, Asthma &

Immunology annual meeting, in Dallas.

" Christmas trees are another possible source of mold exposure during

the holiday season, " said study co-author Philip Hemmers, an

allergist and immunologist with St. 's Medical Center in

Bridgeport, Conn. " Mold allergies peak in the fall, and we see a

second peak with a lot of our mold-sensitive patients during the

holiday season. Our finding correlates with this second peak of mold

sensitivity. "

The researchers studied the mold growth of a live Christmas tree in

a house in Connecticut. Mold reproduce by releasing spores into the

air, so after the live Christmas tree was brought inside the house

and decorated, the researchers measured mold spore counts. These

counts were taken 12 times over a two-week period between Dec. 24

and Jan. 6. The researchers did not assess the types of mold or

whether these molds triggered allergic symptoms in people living in

the house.

The study found that the mold spore count was 800 spores per square

meter (m3) for the first three days. Normal spore counts are less

than 1,000 spores/m3, said Hemmers. However, the spore count rose

after day four, reaching a maximum of 5,000 spores/m3 by day 14.

" This mold spore count is five times above normal. These high levels

have been correlated with allergic rhinitis and an increased rate of

asthma symptoms and asthma-related hospitalization in other

studies, " said Hemmers. " So if you don't feel well during the

holidays, consider the Christmas tree as a possible source of

allergies. "

Hemmers recommended that people with mold sensitivity keep a live

Christmas tree in the house for only four to seven days. An

artificial tree may be a better option for people with mold

allergies, he added, but they carry their own set of problems,

especially if they've been stored in the attic or basement where

they can collect dust and mold.

Although Christmas trees are not a problem for most people with

allergies, said Dr. Khan, an associate professor of internal

medicine at the University of Texas Southwestern Medical Center in

Dallas, there are things you can do to minimize their impact.

" If one is mold-allergic, running an air cleaner in the same room as

the tree could theoretically reduce the mold exposure, but this has

not been studied, " he said. " For some people who are sensitive to

odors, the aroma from the tree, which most people like, could

irritate their nose and cause symptoms. For these people, avoiding

live trees may be best. "

Before people start avoiding live Christmas trees because of their

mold growth, more research needs to be done, said Dr. Dennis Ownby,

a professor of pediatrics and medicine at the Medical College of

Georgia, in Augusta. Since this study only looked at a single tree

in one home, more homes with trees should be investigated, as well

as the types of mold found and whether those molds trigger

allergies. He added that the researchers should also measure mold

counts outside the home and correlate those to indoor mold counts.

Hemmers said that the outdoor mold count was likely low, since the

study was done during the winter. The research team does plan to do

further work this Christmas season by looking at more homes and the

types of mold found.

In addition to Christmas trees, there are other potential holiday

allergens, said Dr. Sublett, section chief of Pediatric

Allergy at the University of Louisville School of Medicine in

Kentucky. These can include foods consumed at holiday parties, such

as nuts and shellfish, and Christmas ornaments and lights that have

been contaminated with dust or mold.

" Store Christmas decorations in plastic containers that you can wipe

off, since cardboard can potentially have mold, " he advised. " Also

wear a N95 dust mask when bringing stuff out of storage. "