When a dark spot needs a doctor

Almost every dark spot on this hub is harmless: marks after pimples, sun spots, melasma. A few dark spots are skin cancer. This page covers the warning signs that a spot needs a dermatologist, the places melanoma hides, and why a spot should be checked before you try to fade it. It is part of Skinli's guide to hyperpigmentation. Skinli cannot look at a spot and tell you what it is. A doctor can.

Never fade a spot before it is checked

The American Academy of Dermatology (AAD) says what looks like an age spot could be skin cancer. It recommends a skin exam by a board-certified dermatologist before you treat age spots. The reason is direct: if you use a fading product on a skin cancer, the cancer can have time to grow and possibly spread. The AAD's page on sun-damaged skin says the same thing, that someone without the right training could mistake a skin cancer for an age spot.

This applies to every product in this hub, from vitamin C to azelaic acid to retinoids. The creams are meant for spots that a doctor would call harmless.

The ABCDE signs of melanoma

Melanoma is a skin cancer that begins in melanocytes, the cells that make skin pigment. Dermatologists created the ABCDEs to help people find it. These are the AAD's definitions:

Letter	Sign	What it means
A	Asymmetry	One half of the spot is unlike the other half
B	Border	The edge is irregular, scalloped or poorly defined
C	Color	Colors vary from one area to the next, such as tan, brown or black, or areas of white, red or blue
D	Diameter	Usually larger than 6 millimeters, the size of a pencil eraser, when found. It can be smaller
E	Evolving	The spot looks different from the rest, or is changing in size, shape or color

The National Cancer Institute (NCI) adds that many melanomas show all five features, but some show only one or two. It says the first sign is often a change in the shape, color, size or feel of an existing mole, and that melanoma may also appear as a new colored or unusual area on the skin.

Other warning signs

The AAD says melanoma can look like:

• A changing mole
• A spot that looks like a new mole, freckle or age spot, but looks different from the others on your skin
• A spot with a jagged border, more than one color, that is growing
• A firm, dome-shaped growth that may look like a sore and may bleed
• A dark brown or black line under a fingernail or toenail
• A band of darker skin around a nail
• A slowly growing patch of thick skin that looks like a scar

The NHS advises seeing a GP for a mole that has changed size, shape or colour, a mole that is painful or itchy, a mole that is inflamed, bleeding or crusty, or a new or unusual mark that has not gone away after a few weeks. The AAD adds a sore that does not heal, or heals and comes back.

MedlinePlus lists other ways skin cancers can look: small, shiny or waxy; scaly and rough; firm and red; or crusty and bleeding. For color changes that are not spots, such as patches that are darker or lighter than your skin with no clear cause, see skin discoloration.

Melanoma often does not hurt

A spot that does not hurt can still be serious. The AAD says you can have melanoma without any pain or discomfort, and that for many people the only sign is a spot with some ABCDE features or a line under a nail. Sometimes melanoma itches, hurts or bleeds. Any of these is a reason to book a visit.

Where melanoma appears on darker skin

The NCI says people with dark skin are less likely to get melanoma than people with fair skin, but tend to be diagnosed with more advanced melanoma, which is harder to treat. Part of the reason is where it appears. The AAD says that in people of African descent, melanoma tends to develop on the palm, the bottom of the foot, or under or around a nail. It also shows a melanoma on the sole of the foot that looked like a bruise.

These places are easy to miss in a mirror. Check them as part of any skin check. The dark spots on darker skin page covers the harmless spots that are common on darker skin.

Harmless spots and how they differ

Spot	Typical look	Why it is usually harmless
Mark after a pimple	Flat, brown, gray, red or pink, where a pimple was	It follows the pimple, and usually fades over months
Sun spot (age spot)	Flat, tan to black, oval, on sun-exposed skin	MedlinePlus says liver spots are not dangerous to health
Melasma	Patches on both sides of the face	The AAD says it is not a cancer or a sign of skin cancer
Common mole	Round or oval, smooth, distinct edge, even color, usually under 5 millimeters	The NCI says only rarely does a common mole turn into melanoma
Seborrheic keratosis	Warty or like a dab of brown candle wax	The AAD says it is harmless, though it can look like skin cancer

The pattern to watch is a spot that breaks from this list: new without a reason, different from its neighbors, or changing.

Unusual moles and your risk

Some people have moles that look different from common moles. The NCI calls them dysplastic nevi, and says some doctors use the term "atypical mole." They are often larger than 5 millimeters, and their color, surface and border can differ from a common mole's.

The NCI says only rarely does a dysplastic nevus turn into melanoma. They are still a risk factor, and the more of them a person has, the higher the risk. Researchers estimate the risk of melanoma is 10 times greater for someone with more than five dysplastic nevi than for someone with none. For these people, the NCI says many doctors recommend a skin self-check once a month and a regular exam by a doctor.

The NCI says people usually do not need moles removed to prevent melanoma. It says few moles turn into melanoma, and most melanomas do not start as moles. It says melanoma more often develops in an area of normal-looking skin, which is why new spots matter as much as old ones.

How to check your skin

The AAD says regular skin checks help find skin cancer early, when it is easier to treat. It estimates that one in five Americans will develop skin cancer in their lifetime. Its steps:

1. Look at your body front and back in a full-length mirror, then each side with your arms raised.
2. Bend your elbows and look at your forearms, underarms, fingernails and palms.
3. Look at the backs of your legs and feet, the spaces between your toes, your toenails and the soles of your feet.
4. Use a hand mirror to check the back of your neck and your scalp, parting the hair.
5. Use a hand mirror to check your back and buttocks.

Photos help you see change over time. The NCI says some people and their doctors photograph unusual moles so changes over time are easier to see. The same monthly photo habit Skinli suggests for acne marks, described in how to take acne progress photos, works for any spot you want to watch.

What happens at the appointment

A dermatologist examines the spot. If a spot looks irregular or unusual, MedlinePlus says a biopsy can check for melanoma. A biopsy means removing a small piece of skin to look at under a microscope.

In the UK, the NHS says that if a GP thinks a mole is melanoma, you will be referred to a hospital specialist, with an appointment within 2 weeks. The main treatment for melanoma is surgery to remove it. The NCI says the earlier melanoma is found and removed, the more likely treatment will succeed.

Lowering your risk

Sun damage adds up. The AAD says ultraviolet light from the sun and tanning beds damages skin each time, and that sun damage can lead to skin cancer. The NHS advises shade between 11am and 3pm, clothing, a hat and sunglasses, sunscreen of at least SPF30 reapplied after swimming, and no sunbeds. The same habits protect against new dark spots of every type.

For the harmless spots, the rest of this hub explains what fades them. Start with how to get rid of dark spots on your face.