Each week, Verywell explains a health term from medicine, science, or technology.
Erythema
How to say it: Erythema (airy-thee-ma)
What it means: It’s a medical term to describe an area of redness, usually on the skin (like a rash or sunburn).
Where it comes from: A lot of medical terms come from either Greek or Latin. Erythema comes from the Greek word erythros, which means “red.”
Where you might see or hear it: If you look at the paperwork that comes with your COVID-19 vaccine, it might say that a side effect could be erythema or redness on the part of your arm where you got the shot.
When you might want to use it: If you aren’t sure whether you need to make an in-person appointment with your doctor, using the term to describe an area of redness on your skin that you think might be a rash can help them assess you—especially if they aren’t able to see it or get a sense of what it looks like from a photo or video.
