Now that Christmas is over, its time to take down that Christmas tree. Real conifer trees used to decorate and celebrate Christmas indoors will contain mould spores and pollens that can be allergenic. After 14 days indoors most will release significant amounts of allergen into the indoor environment. Even artificial trees brought out and rejected in the living room gather significant amounts of dust and moulds. These allergens can trigger asthma, rhinitis and conjunctivitis and perhaps even rashes.