What is the term for the black and blue mark seen under the skin after inserting into a follicle, commonly seen in eyebrows?

The black and blue mark observed under the skin after inserting a needle into a follicle is known as ecchymosis, which is a type of bruising. This occurs when blood leaks from the damaged capillaries into the surrounding tissue, leading to discoloration. It's a common occurrence in procedures that involve puncturing the skin, like electrolysis, especially in sensitive areas like the eyebrows where the skin is thin and delicate.

Scar tissue refers to the fibrous tissue that forms as part of the healing process following an injury, but it would not be seen immediately after the treatment. Hyperpigmentation indicates an increase in skin color or pigmentation in certain areas, often from inflammation or damage, but it does not describe the immediate effect of bruising following a needle insertion. Dermatitis is an inflammation of the skin characterized by redness and irritation, which is unrelated to the bruising phenomenon following a procedure.