I agree with plantladylin....there are SO many Dracaena growing in my neighborhood here (my house included) and it is very sticky and hot in the summer. And they all look old and established, so I think high humidity is fine. Maybe repot it in soil intended for cacti/succulents? I make my own using sand and coir (coconut husk dust...but isn't "dusty"...more crumbly and nice). You can find coir at hydroponic stores or terrarium/reptile shops.
