Freckles

Freckles are clusters of concentrated melanin which are most often visible on people with a fair complexion. A freckle is also called an "ephelis."

Biology

Having freckles is genetic and is related to the presence of the melanocortin-1 receptor MC1R gene variant, which is dominant.[1] Freckles are often found in people with fair hair such as blonde, strawberry blonde, dishwater blonde, or most commonly red hair. The formation of freckles is triggered by exposure to sunlight. The exposure to UV-B radiation activates melanocytes to increase the melanin production, which causes freckles to become darker and more numerous.

Freckles are predominantly found on the face, although they may appear on any skin exposed to the sun. Freckles are rare on infants, and more common on children before puberty; they are less common on adults.

Upon exposure to the sun, freckles will reappear if they have been altered with creams or lasers and not protected from the sun, but do however fade with age in some cases. Freckles are not a skin disorder. People with freckles usually have a lower concentration of photoprotective melanin and are therefore more susceptible to the harmful effects of UV-radiation. An overexposure of UV-radiation should be avoided. Sunscreen has been suggested.