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Freckles
Freckles
It may seem odd to include freckles among the "Diseases and Conditions" section in that freckles are of no medical consequence. However, freckles may cause considerable confusion that may be of medical importance.
What are freckles?
Freckles are flat, circular spots that typically range in the size of the head of a nail. The spots develop randomly on the skin, especially after repeated exposure to sunlight and particularly in persons of fair complexion. Freckles vary in color -- they may be red, yellow, tan, light-brown, brown, or black -- but they are always darker than the skin around them since they are due to deposits of the dark pigment called melanin.
The word "freckle" comes from the Middle English "freken," which, in turn, came from the Old Norse "freknur," meaning "freckled." (Some speakers of Old English and Old Norse must have had a tendency to developing freckles.)
What types of freckles are there?
There are two basic types of freckles -- both with somewhat strange names -- ephelides and lentigines: - Ephelides (singular: ephelis, the Greek word for freckle): This term refers to flat spots that are red or light-brown and typically appear during the sunny months and fade in the winter. They are most often found in people with light complexions and in some families, they are an hereditary (genetic) trait. The regular use of sunscreen during times of sun exposure helps to suppress the appearance of the ephelis-type freckle.
- Lentigines (singular: lentigo, from the Latin word for lentil): Children may develop a small tan, brown, or black spot which tends to be darker than an ephelis-type freckle and which does not fade in the winter. This kind of spot is referred to as lentigo simplex. Although occasionally lentigines are part of a rare genetic syndrome, for the most part they are just isolated and unimportant spots.
What are "liver spots" or "age spots"?
The lentigines that develop in older adults are often called "liver spots" or "age spots." Both terms are misnomers. While freckles do tend to appear over time, they are not in themselves a sign of old age. Instead, they appear on sun-exposed areas in people who have a genetic tendency to develop them. So, they are by no means purely a function of age.
The term "liver spots" is entirely misleading. These spots have nothing whatsoever to do with the liver. They are just the lentigo-type freckles that are commonly seen in older people who are or who have been out in the sun without sufficient sunscreen.
Sometimes, older people who have these lentigo-type freckles also have raised, brown, crusty lesions called seborrheic keratoses. Seborrheic dermatoses are also benign (not malignant) growths of the skin. Although they are most often brown, they can differ in color and range anywhere from light tan to black. They occur in different sizes, too, ranging anywhere from a fraction of an inch (or centimeter) to an inch (2.5 cm) in diameter.
The telltale feature of seborrheic keratoses is their waxy look. They look like they have either been pasted on the skin or may look like a dab of melted brown candle wax that dropped on the skin. Seborrheic keratoses may occur in the same areas as freckles but, since they are not caused by sunlight, they can also be found on covered areas. When they first appear, the growths usually begin one at a time as small rough bumps. Eventually, they thicken and develop a rough, warty surface.
Almost everybody eventually develops at least a few seborrheic keratoses since, like the lentigo-type of freckles, they tend to become more common with age. They are sometimes referred to as the "barnacles of old age."
How do freckles develop?
The sun and sun-tanning lights emit ultraviolet (UV) rays. After exposure to sunlight, the outer layer of the skin (the epidermis) thickens and the pigment-producing cells (the melanocytes) in the skin produce the pigment melanin at an increased rate. (This gives some protection against future sun exposure.)
People differ of course a great deal in their reaction to sunlight. To take an extreme example, there is no pigmentation in the skin of an albino because of a defect in melanin metabolism. On the other hand, people with dark complexions are relatively less sensitive to sun exposure than fair-skinned persons. However, persons with dark skin are not entirely resistant to the effects of the sun, and they, too, can become sunburned with prolonged exposure. Persons with blonde or red hair are especially susceptible since they tend to be the fairest skinned.
Irrespective of skin color, it is the uneven distribution of the melanin pigment in the skin that results in freckling. A freckle is nothing more than an unusually heavy deposit of melanin at one spot in the skin.
How important is heredity with freckles?
The answer, it now appears, is: "Very important." In studies of twins, including pairs of identical twins and pairs of fraternal (nonidentical) twins, it has been found that among identical twin pairs, there was a striking similarity in the total number of freckles found on each person. Such similarities were considerably less common in fraternal twins. This clearly confirms that the occurrence of freckles is influenced by genetic factors. In fact, the variations in freckle counts appear to be due largely to heredity.
What is the medical meaning of freckles?
True freckles pose no health risk at all. This is true for both ephelis-type and lentigo-type freckles. They are all absolutely harmless.
Concern about freckles arises when they are confused with the following, more serious conditions: - Lentigo maligna ("malignant freckle") -- This is a rare condition that generally occurs on the faces of older adults who have a history of considerable sun exposure. Over the course of many years, this condition may, if untreated, develop into a malignant skin cancer . There are of course many hundreds of ordinary facial freckles for every one that is potentially malignant.
- Melanoma -- This very dangerous form of skin cancer may appear even in young people and on parts of the body that are exposed as well as those that are not exposed to the sun. About 40 to 50% of melanomas develop from pigmented moles. However, compared with freckles, melanomas tends to be larger, darker, and more irregular in color and shape than an ordinary freckle.
- Basal cell carcinoma -- This is the most common type of skin cancer . It is usually pearly or reddish, but sometimes it has brownish pigmentation which may allow it to be mistaken for a freckle.
A warning
Anyone who has one or more pigmented spots of which they are not certain should have their physician or dermatologist evaluate them, if only for peace of mind. Even verbal descriptions and photographs cannot convey enough information for satisfactory self-diagnosis. As always, it is better to be safe than sorry.
How can freckles be prevented?
Many people would rather not develop freckles or, if they already have freckles, they would like to get rid of them.
Freckle prevention is obviously better than developing them and then needing to treat them. Therefore, anyone with an hereditary tendency to freckle -- who freckles easily -- should wear sunscreen whenever appropriate and also minimize their sun exposure. The aim here is twofold -- to suppress their tendency to produce freckles and, much more importantly, to reduce their risk of developing skin cancer .
The tendency to freckle easily goes along with the tendency to sun-sensitive skin cancer. Freckles are a warning to people who have them that their skin is highly vulnerable to sunburn and to skin cancer.
How can freckles be treated?
To treat freckles that are already present, several safe and effective methods are available: - Bleaching creams -- Products containing hydroquinone and kojic acid can be purchased without a prescription. Higher concentrations of hydroquinone (over 2%) require a prescription. These products can lighten freckles if they are applied consistently over a period of months.
- Tretinoin -- Sometimes used in conjunction with other bleaching creams, tretinoin (vitamin A acid, Retin-A) also helps to make freckles lighter when applied over a period of time.
- Cryosurgery -- A light freeze with liquid nitrogen can be used to treat freckles.
- Laser treatment -- Several lasers, especially ones that produce a green light, can lighten and eliminate freckles safely and effectively. Like cryosurgery, this is a simple and safe procedure with a high success rate and a low risk of scarring.
The value of freckles?
Freckles can have their value. One is in poetry. For example, without freckles, the American physician, professor, and man of letters, Oliver Wendell Holmes (1809-1894), could not have written:
His home! the Western giant smiles,
And twirls the spotty globe to find it;
This little speck, the British Isles? 'Tis but a freckle, - never mind it. - Freckles can be mistaken for moles and other forms of skin spots.
- Freckles themselves are quite harmless and never develop into skin cancer.
- People may at times confuse freckles with more serious skin problems.
- Conversely, more serious problems such as skin cancer may at times be passed over as a mere freckle.
- Anyone who has one or more pigmented spots of which they are not certain should consult their physician or a dermatologist.
- Effective treatments are available to lighten or eliminate those freckles whose appearance bothers their owners.
Last updated on 07/03/2008
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