Medically reviewed by Renee Nilan, MDMedically reviewed by Renee Nilan, MD COVID arm rash is a delayed hypersensitivity reaction that occurs approximately five days after the COVID-19 vaccine.

It can spread to other parts of your body, including your back, breasts, arms, and buttocks. A PUPPP rash usually goes away on its own and doesn’t cause any scarring or lasting skin color changes.