Actinic lentigo, commonly known as solar lentigo, sun spots, liver spots, or age spots, are common, non-cancerous brownish patches that appear on the skin. These marks develop primarily due to prolonged sun exposure and the natural aging process. They are generally harmless and typically do not require medical intervention.
What Are Actinic Lentigos?
Actinic lentigos are flat, well-defined patches on the skin. Their color varies from light tan to dark brown or black, often with an oval or irregular shape. Sizes range from a few millimeters to several centimeters, and they may occasionally have a slightly scaly surface. They are most frequently found on sun-exposed areas like the face, hands, shoulders, arms, upper chest, and upper back.
The development of these spots is directly linked to chronic exposure to ultraviolet (UV) radiation from the sun or even artificial sources like tanning beds. UV light stimulates melanocytes, the pigment-producing cells in the skin, to produce melanin at an accelerated rate. Over years of sun exposure, this melanin can accumulate in high concentrations, leading to visible actinic lentigos. The aging process also contributes, as these spots are very common in adults over 40 years old, though younger individuals with significant sun exposure can also develop them.
Actinic lentigos are benign and do not progress into skin cancer. They are a common sign of cumulative sun damage and skin aging. Unlike freckles, which often appear in childhood and fade in winter, actinic lentigos are persistent and do not disappear without treatment. Freckles involve increased melanin, while actinic lentigos involve an increased number of pigment-producing melanocytes.
Care and Concerns
While actinic lentigos are benign, many individuals seek treatment for cosmetic reasons. Common cosmetic removal methods include laser therapy, which destroys pigment, and cryotherapy, which freezes the spots. Other options include chemical peels and topical creams with ingredients like hydroquinone, retinoids, alpha hydroxy acids, or vitamin C, which can lighten the spots over several months.
Preventing new actinic lentigos and minimizing the darkening of existing ones requires consistent sun protection. Daily use of broad-spectrum sunscreen (SPF 30+) is recommended, even on cloudy days. Wearing protective clothing, like long-sleeved shirts and wide-brimmed hats, and seeking shade during peak sun hours (10 a.m. to 4 p.m.) also offers protection.
Consult a dermatologist if any spot changes in size, shape, or color, or if it bleeds, itches, or becomes painful. These changes can signal a more serious condition, like skin cancer. Lentigo maligna, for example, is an early form of melanoma that can resemble an actinic lentigo but has irregular borders, variable pigmentation, and enlargement. A professional evaluation is necessary to distinguish benign from potentially cancerous lesions.