Think untangling those Christmas tree lights is the only struggle you'll face this holiday season?

If you have cold symptoms right now, it could be an allergic reaction to your Christmas tree.

Dr. Thomas Klein, the chief of allergy at Delaware County Memorial Hospital, told NBC 10 that real Christmas trees sometimes carry mold.

"The mold spores can be invisible, they are microscope so you breath them in," Klein said. "That can cause, asthma, hay fever, and allergic conditions of the eye."

Although you can't see mold spores, Klein said when picking your real tree, look for any moss growing on the bark. That's a sure sign the tree is carrying mold.

The sap from real trees can also cause some people to break out into a rash.

So, think you'll avoid the symptoms by buying an artificial tree?

"The biggest problem with artificial trees is that they could accumulate dust if they're not cleaned adequately," Klein said.

If you lug your tree out of the attic or basement each year and just start stringing on lights, you're going to have problems.

But it's not just the tree. Better dust off those ornaments, too.

"We want to make sure that when we trim the tree with all the decorations that we don't spew dust into the area from all of the packing material," Klein said.

So how can you avoid dust allergies?

Klein said you should unpack your tree and ornaments outside the house. Wipe down your ornaments with a dry cloth.

Also, wash any fabric decorations in hot soapy water.

And for those who suffer from mold allergies associated with real Christmas trees, try an air purifier with a HEPA filter.