Lentigines are common pigmented spots that appear on the skin, typically flat with a clearly defined edge. These spots are usually harmless and result from an increase in melanocytes, the cells responsible for producing melanin. Lentigines are distinct from freckles and moles, representing a specific type of skin lesion.
Characteristics and Common Forms of Lentigines
Lentigines often present as round or oval spots, varying in color from light brown to dark brown or black. Their size can range from a few millimeters to over a centimeter, and they typically have well-defined, sometimes irregular, borders. Unlike freckles, which often fade in winter, lentigines maintain their pigmentation regardless of sun exposure.
Two primary categories are solar lentigines and simple lentigines. Solar lentigines, also known as age spots or sunspots, are associated with exposure to ultraviolet (UV) radiation. These often appear on sun-exposed areas such as the face, hands, shoulders, and arms. They tend to increase in number and size with age, being common in adults over 40.
Simple lentigines, also known as lentigo simplex, are not linked to sun exposure. They can appear at birth or during childhood and are found on various parts of the body, including the trunk and limbs. These spots are usually small, often 3-15 mm in diameter, and can have either smooth or jagged edges. While generally benign, their cause is not fully understood.
Factors Contributing to Lentigines Development
The development of lentigines is influenced by several factors, with chronic sun exposure being a primary cause for solar lentigines. UV radiation stimulates melanocytes to produce more melanin, leading to the formation of these pigmented spots. Over years, accumulated sun damage can result in melanin clumping in specific areas, forming lentigines.
Genetic predisposition also plays a role in developing lentigines. Individuals with fair skin or those who sunburn easily are more prone to solar lentigines. Aging is another contributing factor, as the skin’s ability to regenerate from sun exposure diminishes with age, making lentigines more common in older populations. These factors collectively lead to an increased number of melanocytes in the skin’s superficial layers and an accumulation of melanin within skin cells.
Differentiating Lentigines from Other Skin Spots and When to Consult a Doctor
Distinguishing lentigines from other skin spots like freckles and moles is important. Freckles (ephelides) darken with sun exposure and typically fade in winter, while lentigines do not. Moles (nevi) can be raised, vary in color and texture, and may be present from birth. Lentigines, in contrast, are usually flat.
While lentigines are generally harmless, monitor any skin spots for changes that might indicate a more serious condition, such as melanoma, a type of skin cancer. Healthcare professionals use the “ABCDEs of melanoma” as a guide for suspicious lesions:
Asymmetry: One half of the spot does not match the other.
Border irregularity: Edges are uneven, notched, or poorly defined.
Color variation: Multiple shades of tan, brown, black, or even red, white, or blue within the spot.
Diameter: Often larger than 6 millimeters, though they can be smaller.
Evolving: Any change in size, shape, color, elevation, or new symptoms like itching or bleeding.
Consult a dermatologist if a new spot appears, or if a spot changes in size, shape, or color. Medical evaluation is also recommended if a spot begins to itch, bleed, or looks concerning. An annual skin check-up is recommended, particularly for individuals with numerous spots or those at higher risk, to ensure early detection of problematic lesions.