: Poinsettias are NOT as poisonous as you think they are. According to POISINDEX (the primary source used by Poison Control Centers) a 50 pound child would actually have to eat around 500 leaves to have a toxic reaction. It's still best to discourage pets and children from tasting it as it can cause nausea and diarrhea. If you have sensitive skin or a latex allergy however, the sap can cause contact dermatitis.