SATURDAY, Nov. 21, 2015 (HealthDay News) -- There are a number of steps people with allergies and asthma can take to deal with the challenges they may face over the holidays, an expert says.

"Two-thirds of allergy sufferers have symptoms year-round, so it's not just a matter of the first freeze hitting and your symptoms disappearing," Dr. Bryan Martin, president of the American College of Allergy, Asthma and Immunology (ACAAI), said in a college news release.

"Even after the pollen season dies down, there are environmental triggers to deal with -- things like mold, dust and pet dander. The winter holidays can bring a whole new set of triggers," he explained.

For example, very cold, dry air can trigger asthma, experts warn. When going outside in very cold weather, people with asthma should cover their mouth and nose with a scarf or face mask, especially if they're exercising.

People with allergies and asthma should pack their medicines if they travel for the holidays. Before you book your stay, check with the hotel to see if it offers allergy-free rooms. If you're allergic to dust mites, bring your allergy-blocking bedding. If you need to carry injectable epinephrine, pack two injectors for your trip, according to the ACAAI.

Artificial Christmas trees and holiday ornaments are likely to be covered in allergy-triggering dust. Give them a thorough cleaning before putting them up. When the holidays are over, store them in air-tight boxes, allergists suggest.

If you get a real tree, be aware that mold spores and pollen can also be brought into the house on fresh trees and greenery. In addition, some people have contact skin allergies to terpene, which is found in the sap of trees.

Food allergies are another holiday concern, according to the ACAAI. If you or a family member has a food allergy, discuss it with your hosts before you attend their gatherings. You also need to check labels of pre-prepared foods that you have not eaten before. There are a number of websites that offer allergy-free recipes for holiday dishes.

More information

The U.S. Centers for Disease Control and Prevention offers holiday health and safety tips.