Brief Answer: freckles are formed due to genetic tendency Detailed Answer: Hello XXXXXXX Welcome and thanks for your query to the forum. As per your query, you have asked about the freckles with or without exposure to sunlight on exposed and unexposed areas to sun-light. Let me elaborate some of the points regarding freckles- Our skin is a multi-layered structure divided into epidermis and dermis. This epidermis is again a superficial multilayered structure. The deepest of the layer of epidermis contains specific cells which are known as melanocytes. These melanocytes are actually the color producing cells which have the tendency to produce color according to its own genetical tendency. So getting from above point you can make out that if a person is fair, his or her tendency to produce color by the melanocytes is lesser than the dark persons and the reverse is present in dark persons where there is higher tendency to produce color universally. Because of this reason we are either fair colored or dark colored individuals. Additionally there is another genetical tendency in fair colored individuals to produce higher color at exposed or non-exposed sites. These areas of higher color production forms the specific entity known as freckles. This type of over production of color in form of Freckling is determined by an autosomal dominant gene ( a specific type of molecular unit of heredity in all organisms which carries specific informations). It is most frequent in individuals with red or blonde hair and blue eyes, red-haired individuals with fair skin. These individuals have a significantly higher incidence of spotty color production the all over skin in form of freckles.They form melanin more rapidly after exposure to sunlight on both exposed or unexposed areas. Even few seconds of sun exposure is sufficient to produce higher color. Therefore on exposure to sunlight freckles are formed as small spots of hyperpigmentation, usually measuring 2–4 mm in size. They first appear at about the age of 5 years as light-brown pigmented spots. They are most numerous on the face, upper back, and dorsal forearms and hands but can be present on less exposed or non exposed sites. They increase in number, size and depth of pigmentation during the summer months and are smaller, lighter and fewer in number in the winter (because of exposure to sunlight). They may be cosmetically disfiguring or may enhance appearance, but are not otherwise of significance and are considered to be simple pigmentation which never causes any problem throughout life. So after reading and analyzing all the points your all doubts must be cleared. I will be happy to help if you have any further doubts. With regards, Dr Sanjay Kumar Kanodia MD- Dermatology

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