Liver spots are a common form of hyperpigmentation that appear on the skin. Despite the misleading common name, these marks have no connection to the health or function of the liver. The proper medical term for these spots is solar lentigines, or sometimes age spots, a benign skin condition resulting from long-term exposure to ultraviolet (UV) radiation.
The Defining Visual Traits
Solar lentigines present as flat patches on the skin, technically classified as macules. Their texture is smooth and they do not feel rough, scaly, or indented. This flat, non-textured quality is a reliable visual trait for identification.
The color range is typically uniform across a single spot, appearing in shades from light tan to dark brown or black. They maintain a consistent color throughout the lesion, unlike some other types of pigmented growths. They generally display a round or oval shape, with distinct, sharply defined borders.
These spots are commonly small, often starting at the size of a freckle, which is a few millimeters, but they can slowly enlarge over time. While most individual solar lentigines remain less than half an inch (about 13 millimeters) in diameter, they can group closely together. When multiple spots cluster, they can create the appearance of a much larger, irregularly shaped patch of discoloration.
Common Body Locations and Development
The placement of solar lentigines on the body directly reflects their cause, as they develop only on areas that have received chronic sun exposure. They are most frequently observed on the face, especially the cheeks and temples, and on the backs of the hands and forearms. Other common sites include the shoulders, upper back, and the tops of the feet.
These marks are a direct result of cumulative damage from UV light, whether from natural sunlight or artificial sources like tanning beds. UV exposure triggers the skin’s melanocytes, the cells that produce the pigment melanin, to overproduce and accumulate the pigment. This leads to the collection of excess melanin in the upper layers of the skin, resulting in the darker color of the lentigo.
Because this development is related to the accumulation of sun damage over a lifetime, solar lentigines are most common in adults over the age of 50. However, they can appear much earlier in individuals with fair skin or a history of frequent, intense sun exposure.
Telling the Difference from Other Marks
It is important to understand the differences between solar lentigines and other common skin growths, such as freckles and moles. Freckles, or ephelides, are similar in color and flatness, but they typically lighten significantly or disappear during the winter months. Solar lentigines do not fade with reduced sun exposure, and true freckles are also more common in childhood.
Distinguishing a solar lentigo from a suspicious mole or early melanoma relies on examining the spot’s characteristics. A lentigo has smooth, regular borders and a single, uniform color. In contrast, potentially concerning spots often exhibit one or more signs of irregularity, sometimes summarized by the ABCDE guide.
These signs include Asymmetry, irregular or ragged Borders, multiple Colors within one spot, a large Diameter, or Evolving changes in size, shape, or color over a short period. If a spot is raised, itchy, bleeding, or rapidly changing, it should be examined by a healthcare provider.