Slapped Cheek syndrome??

[sillytart]

I think my 5yo dd may have slapped cheek syndrome.
She has been very well and still is - no sign of temp, cold, sore throat etc. It started off looking like a raised rash - like she had an allergic reaction to something, but it is not itchy. If you ask her about it she says it is a little sore but otherwise she doesn't complain about it at all.
The rash has changed over a few days and is very deep red on both cheeks (not looking like a rash as such now), I had been giving piriton but it hasnt done anything so this has made me think it is slapped cheek syndrome (especially as it has been going around dd's school), but the teacher says it doesn't look like it to them.
If it is slapped cheek should she be at school? I have found some info saying that once the rash is out she will no longer be contagious, some which says once it has spread to the body then it is no longer contagious.
Not an emergency so can't get a dr's app to confirm.

[MockingbirdsNotForSale]

Fifth Disease/Slapped Cheek is also sometimes characterised by a lacy body rash and can flare up and down for a while and it can be dangerous for a pregnant woman to be exposed to it. Because of this I would want it to be confirmed by a GP/HV. You may want to do this to rule out something like Scarlet Fever. I'm not sure about the school thing- if you call the docs about it, they may be able to advise you over the phone.