Hello and welcome to MedHelp's forums. Thanks for the question! You can attach a picture to your home page if you would like but in general, this sounds like urticaria or hives. https://www.webmd.com/allergies/hives-urticaria-angioedema#1 Those are often raised, itch and can cover large areas. They happen for a variety of reasons including being allergic to something, an insect bite, some people get it from medicine and sun. Is there any way you can get to a doctor to have it looked at? Hives are a histamine reaction so very treatable but would recommend you get them looked at before trying to self treat. Let us know!
Thanks, I have uploaded 2 photos to my profile which might help. Looking at a few dozen photos of hives sufferers, my condition does't look like a good match.
It's always hard to tell from pictures and again, we do recommend you be seen by a doctor for diagnosis. If you put into your search engine, images of mild hives, pictures do look like yours (to me). However, we can look at what else it could be as well. They could also be contact dermatitis. https://www.webmd.com/skin-problems-and-treatments/contact-dermatitis#1
Eczema also can cause itchy raised bumps (treatable with over the counter creams but again, get diagnosed first).
With pityriasis rosea, you have a 'mother patch' often in a place like your back and two weeks later get 'daughter patches' (smaller ones). You often have other symptoms such as sore throat, fever and headache. It's due to a virus. https://www.webmd.com/skin-problems-and-treatments/whats-pityriasis-rosea#1.