What could this rash be? Chest and groin

[FuckOffJeffrey]

DD (6) has an itch rash on her chest and groin (see photo).

Started on groin area on Friday evening and has now spread. She also had a blister on the inside of her lip after school on Friday. I took her to Boots Minor Ailments and they gave her bonjela for it as it hurt and I thought it was a mouth ulcer. This has now practically disappeared.

I've given her piriton to calm the itch and put some diprobase on the rash.

Any ideas what this could be?

Spots don't appear to be blistering (yet). Unsure if she's had chicken pox as when she was exposed the last time (practically the whole toddler group caught it) she got 2 small blister spots on her back but nothing else. She also had scarlet fever a month or so ago and it took 3 weeks and 2 rounds of antibiotics to clear. The rash appears to be different to the sandpaper rah she got with that.

It's really hard to see in that picture, but it looks maybe like a viral type rash. Has she been unwell at all recently?

She's not been unwell since the scarlet fever. Just this rash and the mouth ulcer. I have added another photo but not sure if it's any clearer.

Dd on Friday had a similar looking rash on her chest, which (dh and her childminder assure me) was from lying in grass. Makes sense - I also have a contact allergy to grass occasionally (goes with the crippling hay fever, if guess).
She wasn't otherwise unwell at all. If you have any concerns, do see your GP.
There are all kinds of obscure, harmless rashes out there - dd gets one sometimes that is very rare - our gps had no idea about it, and I only now know what it's called because we happen to know a really knowledgable dermatologist.
I'm sure she is fine. But if you're worried, much better to get it checked out.

Rash still spreading so it will be a trip to the dr tomorrow.

I have added a new picture. Does it look like some are starting to blister to you? Could this perhaps be chicken pox after all? (I always thought chicken pox spots were spaced out a little more)

Does she have eczema? The pp could be right, it could be exacerbated by a contact allergy/contact dermatitis. Let us know what Dr says, im curious

No she doesn't have eczema and hasn't shown any allergy symptoms before. As a baby she never even had nappy rash. She did have cradle cap for a while when she was tiny.

It could be an allergy to something I suppose. I just can't think of anything that has changed recently with products or food. I have really sensitive skin so use surcare or ecover washing powder and we don't do fabric softener. Clothes have been line dried for the most part the past few weeks rather than tumble dried (we also never use dryer sheets). I also have an allergic reaction / rashes to things like vinegar or red wine (sulphates) so we don't use them in cooking.

We have a cat but he's been here over a year now and she's not shown any other pet allergy type of symptoms. (Previously had a dog) Cat has full up to date treatment (advantage) for fleas etc so don't think it's that.

DH has a mild form of Psoriasis on his scalp and one leg but she doesn't appear to have similar symptoms to that either.

I will update after we see the dr, fingers crossed we can get an appointment tomorrow.

What did the Dr say?

McBassyPants Dr said it looks like it was an allergy rash. He gave us some hydrocortisone for it as the diprobase wasn't really helping it. It's looking much better this morning and she's not itching so much. I still can't figure out what would have caused it.