Your symptoms are suggestive of an allergic reaction. I would advise you to visit the ER so that you can get the antihistamine injection which will control the rashes over the body and stunt the spread. You can apply lacto calamine lotion over the rashes which will give you some relief. Do not itch the skin. You will require antihistamines to be taken otherwise as well. If the problem persists or worsens visit the ER at the earliest.
Next Steps
Follow the steps as advised
Health Tips
If condition persists or worsens visit the ER at the earliest