Brown spots and freckles

Freckles

Freckles are small flat brown marks arising on the face and other sun exposed areas. They are most often seen in fair skinned people, especially those with red hair, but they are an inherited characteristic that sometimes affects darker skin types as well.

The medical term for this type of freckle is ephilis (plural ephilides). The colour is due to pigment accumulating in the skin cells (keratinocytes).

Skin pigment (melanin) is made by cells called melanocytes. They don't produce much melanin during the winter months, but produce more when exposed to the sun. The melanin is diffused into the surrounding skin cells, called keratinocytes. The colour of ephilides is due to localised accumulation of melanin in keratinocytes.

Ephilides are more prominent in summer but fade considerably or disappear in winter as the keratinocytes are replaced by new cells.

As the person ages this type of freckle generally become less noticeable. Apart from sun protection, no particular treatment is necessary.

Freckles

Lentigines

Larger flat brown spots on the face and hands arising in middle age also result from sun damage exposure. Unlike freckles they tend to persist for long periods and don't disappear in the winter (though they may fade). Commonly known as age spots or liver spots, the correct term for a single lesion is solar lentigo (plural lentigines).

Lentigines are common in those with fair skin but are also frequently seen in those who tan easily or have naturally dark skin. Lentigines are due to localised proliferation of melanocytes.

It is important to distinguish the harmless solar lentigo from an early malignant melanoma, the lentigo maligna. If the freckle has arisen recently, is made up of more than one colour or has irregular borders or if you have any doubts, see your dermatologist for advice.

Lentigines

Other brown marks

If the brown marks are scaly, they may be solar keratoses (sun damage) or seborrhoeic keratoses (senile warts). In this case there is a proliferation of keratinocytes.

Other brown marks

Solar keratosis

Solar keratosis

Seborrhoeic keratosis

Treatment of brown marks

Brown marks may fade with careful sun protection, broad spectrum sunscreen applied daily for 9 months of the year. Regular applications of anti-aging or fading creams may also help. These may contain hydroquinone, or antioxidants such as:

• alpha hydroxy acids
• vitamin-C
• retinoids
• azelaic acid.

However, 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 may be necessary.

Suitable green-light devices include:

• Flashlamp-pulsed tunable dye laser
• Frequency doubled Q-switched Nd:YAG laser (neodynium:yttrium-aluminium-garnet)
• KTP laser
• Krypton laser
• Copper bromide laser

Suitable red light devices include:

• Q-switched Alexandrite
• Q-switched Ruby

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.

Results are variable but sometimes 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. Unfortunately the treatment occasionally makes the pigmentation worse. Continued careful sun protection is essential, because the pigmentation is likely to recur next summer.

Effect of treatment

Before (left) and after (right) green laser light

Before cryotherapy

After cryotherapy

Follow-up

If there is any doubt whether a brown mark may be a cancer, your doctor may choose to observe the lesion (e.g. with mole mapping or photography) or excise it for pathological examination.