Freckled Girl

Biology
Freckles can be found on anyone no matter their genetic background; however, having freckles is genetic and is related to the presence of the dominant melanocortin-1 receptor MC1R gene variant. The formation of freckles is triggered by exposure to sunlight. The exposure to UV-B radiation activates melanocytes to increase melanin production, which can cause freckles to become darker.
Freckles are predominantly found on the face, although they may appear on any skin exposed to the sun, such as the shoulders. Freckles are rare on infants, and more commonly found on children before puberty. 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 fade with age in some cases. They can also be treated with citric acid. Freckles are not a skin disorder, but people with freckles generally have a lower concentration of photoprotective melanin and are therefore more susceptible to the harmful effects of UV-radiation. It is suggested that they avoid overexposure and use sunscreen.