Hello and hope you are doing well.
The rash could be due to contact dermatitis, that is exposure to an irritant like a chemical or metal or anything you are allergic to, it can cause rash. It could also be due to an allergic reaction to food. We can develop allergies to different things throughout our lifetimes as the allergy develops in response to a repeated stimulus. Also it is possible to develop new allergies, you could develop new allergic reactions to food or other substances. You will only have to closely monitor.
Therapy lies in identifying the allergens and avoiding them and anti histamines. Local measures like ice packs and antipruritic lotions are helpful. Take OTC anti histamines to help with your symptoms. If your symptoms worsen consult your doctor for an evaluation.
Hope this helped and do keep us posted.
I've actually eaten these things before in the past and been absolutely fine. So i don't think it's that.
Thanks for the reply
It looks like hives, which can be an indication of an allergic reaction. It's possible you have an allergy to one of those things you ingested. Please know that the next time could be a worse reaction.