Freckles (LLSN! March 2013)

 Freckles are clusters of concentrated melanin. The formation of freckles is triggered by exposure to sunlight. The exposure to UV-B radiation activates melanocytes to increase melanin production. These melanocytes produce melanin pigment and feed it to keratinocytes, the normal skin cells that form the epidermis, the outermost layer of the skin.



"It might be difficult to get rid of the freckles you already have, but it's not so hard to prevent more from appearing. One way you can do this is by protecting yourself from the sun. Avoid being outside during peak sunlight hours, between 10 a.m. and 4 p.m. If you do need to be outside, make sure that you wear sunscreen with a sun protection factor, or SPF, of at least 15 [source: American Academy of Dermatology]. Try to wear protective clothing that covers your arms and legs. Not only will taking these steps help prevent freckles, it'll help prevent skin cancer as well." -http://health.howstuffworks.com/skin-care/problems/beauty/freckles2.htm

More Sources:

http://en.wikipedia.org/wiki/Freckle

http://www.freckles.org/causes.aspx