Unpacking the Christmas ornaments can trigger allergic reactions. Moving, carrying and unpacking the Christmas boxes stirs up dust and transfers allergens to the hands and the respiratory system. People are first aware of the symptoms while decorating the Christmas tree and assume that the tree is the cause. Wash your hands after unpacking decorations. If you're very concerned about allergy symptoms, allow others to trim the tree.
Artificial trees can be a good alternative, depending on storage.
Just remember to keep it sealed in a plastic bag in an area free of dust and moisture.