Dirty room, dirty bathroom.
The mattress, pillows, and blankets were all musty.
The floor was dusty, and the room smelled damp.
My advice: If you have guests staying overnight, please clean the room first. Open the windows and doors to allow for air circulation. Sweep and mop. Make sure there are no cobwebs in the bathroom.
The mattress, pillows, and sheets are more sensitive; they shouldn't smell damp, which can cause itchy skin.