Brown spots and freckles

Author: Hon A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand, 1997. Updated by Dr Jessica Witherspoon, Resident Medical Officer, Brisbane, Australia. DermNet NZ Editor in Chief: Adjunct A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand. Copy edited by Gus Mitchell. October 2018.


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What are brown spots and freckles?

Brown spots and freckles on sun-exposed skin are ephelides (the plural of ephelis) and lentigines (the plural of lentigo). The difference between an ephelis and a lentigo is that an ephelis fades during the winter months while a lentigo persists in the absence of ultraviolet (UV) stimulation. Ephelides and lentigines can occur in the same individuals and the risk factors for both are generally the same. 

Who gets ephelides?

Ephelides are very common in fair skinned people, especially in children with red hair, when the MC1R gene is thought to be the main gene involved. They are an inherited characteristic that also sometimes affects darker skin types.

What causes ephelides?

An ephelis is brown because of the pigment melanin. Melanin is made by melanocytes and diffused into keratinocytes. Melanin production by melanocytes decreases during the winter months, and increases when the skin is exposed to UV radiation in sunlight. The colour is due to localised accumulation of melanin in keratinocytes. There is no increase in melanocytes.

What are the clinical features of ephelides?

Ephelides arise on the mid-face and sometimes more widely from early childhood onwards. As the person ages this type of freckle generally become less noticeable. They are more prominent in summer but fade considerably or disappear in winter. Each ephelis is usually less than 3 mm in diameter.

Apart from sun protection, no particular treatment is necessary.

Freckles

What are lentigines?

Lentigines are brown flat lesions with a clearly defined edge. The most common type, solar lentigines, arise in middle age and result from sun damage. They are most often found on the face and hands, and are larger and more defined than freckles. Other types of lentigo include ink spot lentigo and lentigo simplex.

Who gets lentigines?

Lentigines are common in people with fair skin but also frequently arise in sun-exposed sites in people who tan easily or who have naturally dark skin. They are common after the age of 40 years but may also occur in younger people.

What causes solar lentigines?

Solar lentigines are caused by UV radiation from exposure to the sun or other forms of UV such as medical treatment (phototherapy) or tanning boothOn biopsy, a solar lentigo has proliferation of keratinocytes forming rete pegs, and there is often also an increase in the number of melanocytes.

What are the clinical features of solar lentigines?

Solar lentigines tend to persist for long periods and they do not disappear in the winter (although they may fade). They vary in size from a few millimetres to several centimetres in diameter. Colour tends to be uniform across the lesion, with a yellowish or grey light brown hue. The border of the lesion is sharply defined, and an irregular border may give it a scalloped shape. They may have a dry or slightly scaly surface.

One or more seborrhoeic keratoses may arise from a solar lentigo.

It is important to distinguish a harmless but atypical solar lentigo from an early malignant melanoma and its subtypes, lentigo maligna and lentiginous melanoma. Clinically, dermoscopically, or histologically atypical lesions should be completely removed by surgical excision with pathological examination.

Lentigines

How are brown spots and freckles diagnosed?

Most ephelides and lentigines can easily be diagnosed clinically by a health practitioner trained in examining the skin. If there is any doubt whether a brown mark may be a cancer, the lesion may be monitored (with digital dermatoscopic surveillance) or excised for pathological examination.

What is the differential diagnosis for freckles and solar lentigines?

A brown mark may also be an actinic keratosis (sun damage) or a seborrhoeic keratosis (senile wart) in which there are proliferations of keratinocytes. These tend to be more scaly and thickened than solar lentigines. Facial pigmentation may also be due to melasma, a chronic pigmentary disorder.

Other brown marks

What is the treatment for brown spots and freckles?

Prevention of brown marks

Not all brown marks can be prevented. Careful sun protection will reduce the number of new solar lentigines. Staying out of the sun and using sun protective clothing is much more effective than sunscreens alone. Sunscreens must have high sun protection factor (SPF 50+) and good broad-spectrum cover, and they should be applied liberally and frequently.

Treatment of brown marks

Brown marks may fade with careful sun protection, such as applying broad spectrum sunscreen daily. Regular applications of anti-aging or fading creams may also help.

These may contain hydroquinone, or antioxidants such as:

Tyrosinase inhibitors such as:

Melanosome inhibitors such as:

  • Niacinamide (B3)

Brown marks may be removed more rapidly and effectively by chemical peels, cryotherapy or certain pigment lasers that target melanin in the skin. Multiple treatments are often necessary.

Suitable green-light devices to remove epidermal pigment include:

  • Flashlamp-pumped pulsed dye laser
  • Frequency doubled Q-switched Nd:YAG laser (neodynium:yttrium-aluminium-garnet)

Suitable red-light devices include:

Intense pulsed light has a similar effect. Carbon dioxide and Erbium:YAG lasers vaporise the surface skin thus removing the pigmented lesions. A fractional laser may also be effective. More recently, picosecond lasers are being used.

Results of laser and light treatment are variable but sometimes are very impressive with minimal risk of scarring.

With superficial resurfacing techniques, there is minimal discomfort and no down-time but several treatments are often necessary. The treatment occasionally makes the pigmentation worse by causing postinflammatory pigmentation. Continued careful sun protection is essential, because the pigmentation is likely to recur the next summer.

Effect of treatment

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