DALLAS, TX -- November 13, 2007 -- People who are mould-sensitive may experience extra allergy symptoms while having a live Christmas tree in the home, researchers reported here at the American College of Allergy, Asthma and Immunology (ACAAI) 65th annual meeting.

   In a poster presentation, John Santilli, MD, Chief of Allergy and Immunology, Department of Medicine, St Vincent's Hospital, Bridgeport, Connecticut, reported results of a study examining the amount of mould that collects on Christmas trees.

   "I had a suspicion that mould was a big problem, so a resident here at the hospital volunteered to investigate," he said in an interview. "He didn't believe Christmas trees posed a significant allergy risk," Dr. Santilli said.

   The researchers used an Allergenco MK-3 Air Sampler to perform mould counts 12 times over a 2-week period, from December 24 to January 6, after a live Christmas tree was brought into a home and decorated. The home temperature was kept between 65 and 68 degrees, and the tree was placed about 10 feet from a heat vent.

   For the first 3 days, counts remained at 800 spores/m3 (normal values: 500-700 spores/m3), but rose to a maximum of 5,000 spores/m3 by day 14, when the tree was taken down. The counts went up with each day during the 14-day period.

   "The good news is that physicians can be aware of the problem, if patients come in with running noses and sniffling," said Todd Mahr, MD, Chair, ACAAI Abstract Review Committee, Director of the Pediatric Allergy and Clinical Immunology, Gundersen Lutheran Medical Center, La Crosse, Wisconsin, United States.

   "The study is very impressive because you can see that the mould spores' counts go up over the 12 days, and it's not surprising that the trees, which are cut and bundled now and then shipped, making them a ripe source for mould," he said in an interview.

   "Allergies sufferers may want to ramp up their medications during the season," Dr. Mahr suggested.

   The authors have no disclosures; the study was unfunded.

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