Solar Lentigo

Overview

A solar lentigo (plural: solar lentigines) is a flat, harmless brown spot on the skin caused by years of sun exposure. These spots are very common in middle-aged and older adults and are often called age spots, liver spots, or sun spots, even though they have nothing to do with the liver and are simply a sign of sun damage.

Solar lentigines appear on areas that get the most sun over a lifetime, such as the face, the backs of the hands, the shoulders, and the forearms. They are benign and do not turn into cancer, but because some skin cancers can look similar, any spot that changes in size, shape, or color should be examined. They overlap with broader photoaging and the everyday term age spots.

Because solar lentigines are so common, most people develop at least a few as they get older, especially if they have spent a lot of time in the sun. They tend to become more numerous over the years and may darken with further sun exposure. While they are purely cosmetic, knowing how to tell them apart from more serious spots gives peace of mind and helps catch skin cancers early.

Symptoms

Solar lentigines have a typical, recognizable appearance:

• Flat spots that are level with the surrounding skin
• Tan, brown, or dark brown color
• Round or oval shape with fairly defined edges
• Range from small to about a centimeter or more across
• Found on sun-exposed areas like the face, hands, shoulders, and forearms
• Usually multiple spots, and they do not itch or hurt

Because they look like other pigmented spots, it is worth knowing the warning signs of skin cancer: a spot that grows, changes color, becomes uneven, bleeds, or develops irregular borders should be checked promptly.

Causes

Solar lentigines are caused by ultraviolet (UV) light damaging the skin over time:

• Cumulative sun exposure: Years of UV light trigger pigment-producing cells (melanocytes) to make extra melanin in patches.
• Tanning beds: Artificial UV light has the same effect as sunlight.
• Skin and age factors: Fair skin and older age make these spots more likely, as damage accumulates over decades.

They are a visible record of past sun exposure rather than a disease, which is why they tend to increase with age and in people who have spent a lot of time outdoors.

Risk Factors

• Fair skin that burns easily
• A history of frequent sun exposure or sunburns
• Use of tanning beds
• Older age
• Living in sunny climates or working outdoors
• A history of significant photoaging

Diagnosis

Solar lentigines are usually diagnosed by appearance:

• Skin examination: A doctor or dermatologist can often identify them by sight.
• Dermoscopy: A magnified, lighted view of the spot to look at its pattern more closely.
• Biopsy: Rarely needed, but a small sample may be taken if a spot has features that could suggest skin cancer.

The main reason to have new or changing pigmented spots evaluated is to rule out skin cancers such as melanoma, which can occasionally resemble a harmless age spot.

Treatment

Solar lentigines are harmless and do not need treatment, but they can be lightened or removed for cosmetic reasons:

• Topical lightening creams: Prescription or over-the-counter products that fade pigmentation over time.
• Cryotherapy: Freezing the spot with liquid nitrogen.
• Laser or light therapy: Targeting the pigment to fade the spot.
• Chemical peels and microdermabrasion: Procedures that remove the top layer of skin.

These treatments are done by a clinician, and results vary. Protecting the skin from further sun is important to prevent spots from returning or darkening.

Prevention

• Use a broad-spectrum sunscreen of SPF 30 or higher daily
• Reapply sunscreen during prolonged sun exposure
• Wear hats, sunglasses, and protective clothing
• Avoid the sun during peak midday hours when possible
• Do not use tanning beds
• Check your skin regularly and note any changing spots

When to See a Doctor

See a doctor or dermatologist if a pigmented spot changes in size, shape, or color, has irregular or uneven borders, itches, bleeds, or looks different from your other spots. Have any new dark spot checked if you are unsure. While solar lentigines are harmless, prompt evaluation of changing spots is important to catch skin cancers like melanoma early, when they are most treatable.

Related Topics

Frequently Asked Questions

References

1. American Academy of Dermatology (AAD). Age spots and how to treat them.
2. Mayo Clinic. Age spots (liver spots).
3. MedlinePlus, U.S. National Library of Medicine. Aging changes in skin.
4. Skin Cancer Foundation. Sun damage and pigmentation.