Mold and dust can also accumulate on artificial trees, wreaths and greenery when they are stored, so make sure you clean these items thoroughly after you unpack them. Wash fabric decorations in hot water and soap, and wipe down plastic, tin, glass or ceramic ornaments and decorations to eliminate dust.
Other potential holiday culprits include strong scents from potpourri and candles. Asthma can also be triggered by smoke from a fireplace in a poorly ventilated room—and, of course, holiday stress.
If you're traveling to a home with decorations, or pets, that might trigger a reaction, take your medicine with you. Holiday parties and an abundance of homemade foods can also pose extra problems for people with food allergies. It's especially important for them to bring along epinephrine to control potentially life-threatening reactions.
"Education and avoidance are the only ways to cope with food allergy," Georgeson says. "So let your hosts know if you have a food allergy and bring your Epi-pen"—a device that injects epinephrine—"in case of accidental exposure."
Georgeson notes that accidental cross-contamination can be an issue with home-baked goods. For example, someone might bake cookies on a baking sheet contaminated with a food allergen, or pack nut-free cookies in a tin that once contained brownies with nuts and wasn't washed out afterward.
But you don't have to skip the holiday season just because you have allergies and/or asthma.
"The biggest piece of advice is to make sure you have your medicines with you wherever you are," says Georgeson. "And if you have an allergy, alert the person who you're visiting, so you can enjoy a safe holiday."