Unknown disease/ viral infection any ideas?

[Monkeybar]

I started with this under 'insect bites under nappy', but it's developed from there! Started with 1 little pimple/bite looking thing under nappy Sat. 2 more on Sun and 2 on knee Mon.
Took ds to GP on Tues as smaller little bumps had appeared on his legs (around 2 large bite/blister looking things. I thought it might be chicken pox (1st time mum, here!). GP said insect bites.
Wednesday, he had one on his toe and one on his thumb.
Yesterday, nursery rang to say they'd hed hand foot an dmouth and that they thought ds had it. Took him to different GP who said it wasn't h,f&m ass he didn't have lesions on his hands and feet - so I pointed out the very small ones that were there and she changed her diagnosis to say that it WAS h,f & m.
Took ds to be weighed today (told hvs about the spots before I went in). They said that if they'd seen the one on his toe in isolation they'd have said Chicken Pox. But it could also be hf&m or a post viral rash from the rotavirus he had at the start of May. The ones under his nappy have dried, but don't look the way CP blisters look, apparently!
So, I'm no wiser as to what they are or what to do. He seems fine in himself, has no temperature, and eats well (no blisters in mouth). Any ideas what they might be, please?

[chapsmum]

so many could be's..
could be a heat/sweat rash?
could also be like they say a viral rash.
This can happen when the body is 'allergic' to the virus.
virus' can linger in the body and return ona cyclical basis and I was told by a dermatologist that the rash (urticharia) can return for up to 14 day especially when they are hot. The nappy is one of the hottest places in the world!!!
If they are well in them selves I really would not worry.

HTH