Freckles (cont.)

There are two basic types of freckles: simple freckles and sunburn freckles. Simple freckles are usually tan, round, and small -- about the size of a common construction nail head. Sunburn freckles are often darker, have irregular jagged borders, and may be larger than a pencil eraser. Sunburn freckles are more common on the upper back and shoulders where people frequently get their most severe sunburns.

Ephelides (singular: ephelis) is the Greek word and medical term for freckle. This term refers to flat spots that are tan, slightly reddish, or light brown and typically appear during the sunny months. They are most often found on people with light complexions, and in some families, they are a hereditary (genetic) trait. People with reddish hair and green eyes are more prone to these types of freckles. Sun avoidance and sun protection, including the regular use of sunscreen, may help to suppress the appearance of the some types of freckles.

Lentigines (singular: lentigo) comes from the Latin word for lentil and is the medical term for certain types of darker freckles and sunburn freckles. Lentigines tend to be darker than the common freckle and do not usually 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.

"Liver spots" or "age spots" are the common names of the darker spots seen in adults, frequently on the back of the hands. The term "liver spot" is actually a misnomer since these spots are not caused by liver problems or liver disease. While freckles do tend to appear over time, they are not in themselves a sign of old age. Instead, they appear generally on sun-exposed areas, more so in people who have a genetic tendency to develop them. So, they are by no means purely a function of age.

These spots are just the lentigo-type freckles that are commonly seen on the skin of older adults with a history of sun exposure.

Sometimes, older people who have these lentigo-type freckles also have raised, brown, crusty lesions called seborrheic keratoses in or around the same areas. Seborrheic keratoses are also benign (not malignant) growths of the skin. Some patients call these growths "barnacles" or "Rice Krispies." Although they are most often medium brown, they can differ in color ranging 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. Typically, these growths are around the size of a pencil eraser or slightly larger. Some keratoses begin as a flat lentigo and gradually raise and thicken to form a seborrheic keratosis.

The telltale feature of seborrheic keratoses is their waxy, stuck-on, greasy 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. Seborrheic keratoses are also more common in areas of sun exposure, but they may also occur in sun-protected areas. When they first appear, the growths usually begin one at a time as small rough bumps. Eventually, they may thicken and develop a rough, warty surface.

Seborrheic keratoses are quite common especially after age 40. Almost everybody may eventually develop at least a few seborrheic keratoses during their lifetime. They are sometimes referred to as the "barnacles of old age."

Source: MedicineNet.com
http://www.medicinenet.com/freckles/article.htm