The presence of reddish hair and small, pigmented spots on the skin is a common characteristic. These spots, known scientifically as ephelides, are small, concentrated areas of increased melanin production. Individuals with red hair frequently exhibit this trait due to a shared genetic basis.
The tendency for individuals with red hair to develop these skin marks stems from the effects of the melanocortin 1 receptor (MC1R) gene. Variations within this gene lead to reduced production of eumelanin, which is responsible for darker pigmentation, and a relative increase in pheomelanin, a pigment that produces reddish-blond hues. The relative absence of eumelanin makes the skin more susceptible to UV radiation, and the increased production of pheomelanin contributes to the formation of small, concentrated spots of pigment after sun exposure. Historically, awareness of this sensitivity has led to cultural associations with caution in sunlight and an increased risk of sunburn.