Just had a call from TS, they are home!
The doctors are fairly baffled, but as the rash has stopped spreading and DS is not ill (apart from the painful legs) they thought he & TS would be better off going home. He has oral antibiotics and she's been given a direct number to ring in case he does become ill overnight - she plans to put him in her bed so she can keep an eye on him.
She's not planning to log on for a bit as she needs to wind down first but may be on later.
Phew!
SC, sorry to hear about DD, hope it's nothing serious, and fmf, thanks for your post. This kind of thing seems to be more common than we might think.