Freckles are small flat brown marks arising on the face and other sun exposed areas. They are most often seen in fair skinned people, especially those with red hair, but they are an inherited characteristic that sometimes affects darker skin types as well.
The medical term for this type of freckle is ephilis (plural ephilides). The colour is due to pigment accumulating in the skin cells (keratinocytes).
Skin pigment (melanin) is made by cells called melanocytes. They don’t produce much melanin during the winter months, but produce more when exposed to the sun. The melanin is diffused into the surrounding skin cells, called keratinocytes. The colour of ephilides is due to localised accumulation of melanin in keratinocytes.
Ephilides are more prominent in summer but fade considerably or disappear in winter as the keratinocytes are replaced by new cells.
As the person ages this type of freckle generally become less noticeable. Apart from sun protection, no particular treatment is necessary.