Could this be a Nutella allergy? Rash appeared hours later and worsened the following day

[Loughranx]

Hi everyone,
I'm hoping someone can share their experiences as I'm feeling really worried.
Yesterday, I think my daughter may have had a spoonful of her brother's Nutella. I'm not actually sure if she did, but it was around 5–6pm.
I put her to bed at around 8pm, and when she woke up, she had what looked like a heat rash. She was otherwise well, so I sent her to school this morning.
When I picked her up at 12pm, the rash had spread and was noticeably worse. I sought medical advice and took her to A&E as it was spreading quite quickly.
The doctors said it looked like an allergic reaction and advised me to contact our GP for a referral to an allergy clinic. However, they also said it could potentially be a viral rash.
I'll upload some pictures.
I've never seen a viral rash like this before, so I'm wondering if anyone has experienced something similar.
Could this be an allergy to Nutella, and can an allergic reaction appear several hours after eating it and then get worse the following day?
Has anyone else's child had a rash like this? Does it look like an allergic rash to you, or has anyone experienced a viral rash that looked similar?
Any experiences would be really appreciated. Thank you.

Has she eaten Nutella before? And other things with nuts in? Rashes are worrying, but in my experience often an unexpected, or even unknown cause. It"s worth getting checked out, but try not to panic.

I can't see the photo yet, but my DS had an awful post-viral rash that looked similar to other illnesses. My DD had an unexplained rash as a baby and we never knew quite what caused it. Sometimes 2 things seem to interact and that's how the body responds.

I don't have any experience with allergies, so can't comment if it's normal to develop a rash quite a while later. Go ahead with advice from the GP, but try not to worry too much if you can.

How old is she? Has she had nuts before? Did she react to those?

@readingmakesmehappy sorry am only replying she is 4 years old she had a milk allergy when she was a baby she had one bite of a pancake with Nutella couple weeks ago next day had a few spots on her leg but looked more like bite marks didnt think anything of it then on monday evening i think she took a spoonful of her brothers Nutella went to bed couple hours later woke to a rash on belly and back and it got increasing worst I was and I was worrying with the increase of the rash spreading so seeked medical advice they did state it looked like a allergy rash but cause am unsure if she had Nutella they are unsure but could very much be a viral rash so they give her allergy medication to take for the next 10days and told me to contact her GP and ask for a refrella to allergy clinic I called them explained today that the rash is fading its blochy raised hives and appearing worst in other areas but they where pretty dismissive and said allergy testing can take years and I dont think its that and looks more viral but I never saw a viral rash like that before maybe it is but I wish pictures would upload here