Another Day, Another Hospital

I just got back from UCI hospital, where dad has been admitted. Ever since he got out of Saddleback on Thursday afternoon, he has been getting weaker and weaker, less able to walk, spending all his time sleeping (none too well) and not eating well either, which is unusual for him.
I went to his house this morning to water his plants, as promised. When I came back into the room to see if he was up, he started from his bed looking totally deranged and yelling that the bed was moving, and that I should put my hand on it. I did. It was of course not moving.
He could barely stand up, and his lip was swollen up. On his back, I soon discovered, there were red hives or some sort of lesion, not a lot of them, but some. He told me that he was hearing for the past week music in his head all the time he was sleeping, the same two songs, played over and over and over. He had no idea where they came from, though they sounded as if they were coming from outside his head. They weren't. They didn't continue when he got up, though.
After several tests, the doctors decided to keep him. We were there till 5:30 or 6:00 PM before he got to his room. I went across the street and bought him a Sudoku book, gave it to him, and went home.
I don't know how long they will keep him, or if it will help, but he asked a good question. Why did he get worse at home? Is there something there that is causing problems? Perhaps he is allergic to the detergent they are using. I should talk to them about this.