Freckling: Causes, Types and When to Worry

What freckles are

Pigment cells (melanocytes) in the skin make melanin, which protects deeper layers from ultraviolet (UV) light. In a freckle, the number of pigment cells is normal, but those cells make more melanin than the surrounding skin in response to sun. That is why freckles appear on the face, shoulders, arms and back, and why they darken with each summer.

Freckling is strongly inherited. Variants of the MC1R gene, the same gene linked to red hair and fair skin, are the main reason some people freckle heavily and others hardly at all. Freckles usually appear from about age 2 to 4, increase through childhood, and often become less noticeable in adulthood.

Freckles vs sun spots vs moles

Age spots, also called solar lentigines or liver spots, are the "freckles" that many adults notice appearing on the backs of the hands, face and shoulders after years of sun. Unlike true freckles, they are caused by an increased number of pigment cells and do not fade in winter.

New freckles in adults

New freckle-like spots in adulthood are usually sun spots from cumulative UV exposure, including tanning beds. Other causes:

• Melasma: larger patches of brown pigment on the cheeks, forehead and upper lip, triggered by hormones (pregnancy, birth control pills) and sun.
• Post-inflammatory pigmentation: brown marks left after acne, eczema or injury.
• Seborrheic keratoses: waxy, "stuck-on" brown growths that start flat and become raised.
• Lentigo maligna: a slowly enlarging, irregular brown patch on sun-damaged skin of older adults. It is an early form of melanoma, so a growing irregular patch on the face needs a dermatologist's review.

Freckling that points to a medical condition

Freckles in places the sun does not reach are a clue to genetic conditions:

• Neurofibromatosis type 1: freckling in the armpits or groin (Crowe sign), together with six or more coffee-colored patches (café-au-lait spots) larger than 5 mm in children or 15 mm after puberty, and soft bumps on or under the skin. See the page on neurofibromatosis.
• Peutz-Jeghers syndrome: dark freckles on the lips, inside the mouth and on the fingers, appearing in childhood, with polyps in the bowel.
• Xeroderma pigmentosum: a very rare condition with extreme sun sensitivity and heavy freckling in early childhood.

Freckles and skin cancer

Freckles themselves do not turn into cancer. But people who freckle easily have skin that burns easily and has less natural protection, so they have a higher risk of melanoma and other skin cancers. Check your skin monthly using the ABCDE guide:

• Asymmetry: the two halves do not match
• Border: ragged, notched or blurred
• Color: several shades of brown, black, red, white or blue
• Diameter: larger than 6 mm, though melanomas can be smaller
• Evolving: changing in size, shape, color or height, or new symptoms such as bleeding

How doctors assess freckling

A primary care doctor or dermatologist examines your skin, often with a dermatoscope, a handheld magnifier with a light. Typical freckles need no tests. A spot that looks unusual is photographed for monitoring or removed and sent for biopsy. Freckling in unusual places, together with other skin features, may lead to genetic evaluation.

Treatment and prevention

Freckles need no treatment. If you want to make them less visible:

• Sun protection is the most effective step: broad-spectrum SPF 30 or higher every day, reapplied every 2 hours outdoors, plus hats and shade between 10 a.m. and 4 p.m.
• Topical lighteners such as hydroquinone, azelaic acid, retinoids or vitamin C can fade spots over months. Some need a prescription.
• Laser and intense pulsed light (IPL) treatments remove freckles and sun spots effectively, but they return with sun exposure.
• Chemical peels and cryotherapy are other options a dermatologist may offer.

Have any spot that is irregular or changing checked before cosmetic treatment, so a melanoma is not removed without diagnosis.

Frequently asked questions

What causes freckles?

Freckles form when pigment cells make extra melanin in response to sunlight. How much a person freckles depends mainly on genes, especially variants of the MC1R gene linked to fair skin and red hair. More sun exposure means more and darker freckles.

Are freckles a sign of sun damage?

True childhood freckles are a sign of sun sensitivity more than damage. Sun spots that appear after age 40 and stay year-round are a sign of cumulative sun damage. Both indicate skin that burns easily and benefits from sun protection.

Can freckles turn into melanoma?

No, freckles themselves do not become cancer. But people with many freckles have a higher melanoma risk. Watch for any spot that is asymmetric, irregular, multicolored, larger than 6 mm or changing, and have it checked.

Why do I have freckles in my armpits?

Freckles in the armpits or groin, where the sun does not reach, are a classic sign of neurofibromatosis type 1, especially with several coffee-colored patches on the skin. A doctor should examine you to confirm or rule it out.

Do freckles go away?

Many freckles fade in winter and become lighter with age. Sun spots that appear in adulthood do not fade on their own, but they can be lightened with creams, peels or laser treatment. Daily sunscreen prevents new ones forming.