Freckles

For other uses of the word, see Freckles (disambiguation).

Freckle
Classification and external resources
Facial freckles on a child.
10 L81.2
MeSH D008548

Freckles are clusters of concentrated melanin which are most often visible on people with a fair complexion. A freckle is also called an “ephelis”. Freckles do not have an increased number of melanin producing cells (melanocytes). This is in contrast to lentigines and moles.[1]

Contents

Biology

Extremely freckled women. Freckles cover the face, chest and shoulders

Freckles can be found on anyone no matter their genetic background; however, having freckles is genetic and is related to the presence of the melanocortin-1 receptor MC1R gene variant.[2] 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 and more visible.

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 lasers and not protected from the sun, but do fade with age in some cases. Their intensity can be altered 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 [4]

Freckles on the arm

Types of freckles

Ephelides describes a freckle which is flat and light brown or red and fades with reduction of sun exposure. Ephelides are more common in those with light complexions, although they are found on people with a variety of skin tones. The regular use of sunblock can inhibit their development.

lentigines) are freckles that may not fade in the winter. Rather, they form after years of exposure to the sun. Liver spots are more common in older people.

See also

References

Notes
  1. ^ Robbins and Cotran Pathologic Basis of Disease Elsevier. 2005. Page 1232. ISBN 0-8089-2302-1 .
  2. ^ Online ‘Mendelian Inheritance in Man' (OMIM) 266300
  3. 17015167.
  4. http://www.ajph.org/cgi/reprint/82/4/614.
Bibliography

External links

This article uses material from the Wikipedia article Freckles, which is released under the Creative Commons Attribution-Share-Alike License 3.0.

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