What is the medical term for redness of the skin?

Erythema is the medical term specifically used to denote redness of the skin, which occurs when the blood vessels near the surface of the skin dilate, leading to increased blood flow in that area. This condition can be a response to various factors such as injury, infection, or inflammation. While it is a sign often associated with other conditions, it is distinctly identified as redness due to vascular changes.

Hyperemia refers to an increased blood flow to a specific area, which can also cause redness, but it is a broader term not restricted to the skin and can occur in internal organs as well. Inflammation encompasses a series of physiological responses to harmful stimuli, including redness, but it is a more general term that implies additional signs like swelling and pain. Dermatitis refers specifically to skin inflammation that may include redness, but it describes a broader category of skin conditions characterized by inflammation rather than simply the presence of redness alone. Thus, erythema is the most precise term for describing skin redness.