Ask Smithsonian: What Is a Freckle?

Freckles are frequently thought of as cute, but they are also the first warning sign that the skin may have received too big a dose of solar radiation.

The word freckle, first used in the 14th century, arose out of the middle English word freken, which is probably of Scandinavian origin, according to Webster’s dictionary. The layman’s term freckle can stand for two distinct dermatologic entities—ephelides and lentigines.

“We call them all freckles, but they are different,” says Nada Elbuluk, a dermatologist at the Joan H. Tisch Center for Women’s Health at NYU Langone Medical Center.

Both ephelides (the plural of ephelis) and lentigines (the plural of lentigo) are benign conditions. They don’t turn into skin cancer, but both “are a marker of how much sun damage you’ve had,” says Elbuluk.

And, she says, the lesions “indicate you’re at risk” for skin cancer.

Skin type determines both the probability of freckling and the risk of skin cancer. People on the lower end of the Fitzpatrick skin type scale have a higher risk. The Fitzpatrick scale—which ranges from very light (Type 1) to very dark (Type VI)—was developed in 1975 by Thomas Fitzpatrick of Harvard Medical School.

Freckle-faced kids have ephelides. These pencil-nub-sized brown spots tend to start appearing around age 2 or 3, but generally only in kids who have a genetic predisposition. Mostly, those who get ephelides have fair skin and fair or red hair. Girls seem to have them more than boys.

The ephelides get darker in reaction to sun exposure, and are usually found on the face, arms, chest and back. Having severe sunburn before age 20 tends to increase the likelihood of ephelides.

However, ephelides can fade—even over the winter—and they tend to disappear altogether by young adulthood, says Elbuluk.

Lentigines, however, only appear in response to sun exposure and become more numerous over time with age. As many as 90 percent of white Americans age 60 or more and a fifth of those under age 35 have lentigines.

Lentigines tend to be large—up to 1 to 2 centimeters across—and they can have irregular shapes, whereas ephelides are usually rounded and only 1 to 2 millimeters across.

Freckles are also different than moles, which are small, usually dark and can be flat or raised. They start developing in childhood or adolescence and pretty much stay the same throughout life, although atypical moles can morph into potentially cancerous growths after exposure to sunlight.

The only way to prevent freckles is to avoid sun exposure or use lots of sunscreen. Modern medicine also offers some solutions to those who think freckles aren’t so alluring.

“There’s definitely a cosmetic market for people who don’t like them and want to reverse time and some of the sun damage,” says Elbuluk. Dermatologists can use lasers, liquid nitrogen, chemical peels and other tools to remove ephelides and lentigines here and there, just not in huge swaths.

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Alicia Ault | | READ MORE

Alicia Ault is an independent journalist whose work has appeared in the New York Times, the Washington Post, Medscape Medical News, WebMD and Wired. She splits her time between St. Petersburg, Florida, Washington, D.C., and New Orleans, exploring the rich variety of food, music, art and culture on offer in those cities.