Allergist Dr. Richard Weber, president-elect of the American College of Allergy, Asthma and Immunology, said people returning home after visiting relatives for the holidays or college students back for Thanksgiving or winter break may develop a severe allergy to a family pet they hadn't been allergic to before.
This flare-up of pet allergies is called the Thanksgiving Effect -- an allergist can help a patient cope with a sudden allergy to Fifi or Fido, Weber advised.
For the more than 40 million Americans, who suffer from allergies and asthma, the holidays could also be one of the stuffiest times of year.
To avoid asthma or allergies, use natural aromas, Weber advised. Pumpkin, gingerbread and pine-scented air fresheners can be inviting, they can also be hazardous.
About one-third of people with asthma report health problems from air fresheners, which contain volatile organic compounds. Studies indicate VOC exposure even less than accepted levels can increase the risk of asthma in children, Weber said.
Open windows to air out the house or let the scents from the oven provide natural aromas, Weber said.
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