Britannica
Sources used in this answer
Why does skin sometimes become darker after prolonged inflammation?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
skin disease
Visible alterations in the texture of the skin, such as rashes and hives, can be indicative of serious disease. For example, one of the first signs of Lyme disease is a circular rash in a bull's-eye pattern on the skin.
Skin often becomes darker following prolonged inflammation due to a process known as postinflammatory pigmentation. This darkening occurs because melanocytes—the specialized cells responsible for producing the skin-darkening pigment melanin—increase their production of pigment in response to the inflammatory state.123
It is important to note that this change is not caused by an increase in the number of melanocytes themselves, but rather by the overproduction of melanin. This reaction is a common outcome of various inflammatory skin disorders, such as acne vulgaris, chronic dermatitis, and lichen planus, and it is observed more frequently in individuals with darker skin tones.13