Everyone has moles. Most people think of a mole as a dark brown spot, but moles have a wide range of appearances. Moles can appear anywhere on the skin, even in areas that have not been exposed to the sun. Most appear during the first 20 years of life, although some may not appear until later in life. The number of moles you have is determined by family history and the amount of sun exposure during childhood (more sun = more moles).
Each mole has its own growth pattern. At first, moles are flat and tan, pink, brown or black. Over time, they usually enlarge and rise up from the skin forming a bump, some even develop hairs. The color usually lightens. The lifecycle of a mole takes about 50 years. Moles may darken with exposure to the sun or if women are on birth control or pregnant. Most moles cause no problems, but there are few types that need closer attention.
Recent studies have shown that some moles have a higher-than-average risk of becoming cancerous. One is congenital nevi, which are moles present since birth. Congenital nevi tend to be larger, darker, and hairier. When a congenital nevus is more than 8 inches across, it poses the greatest risk for developing melanoma.
The other type of mole at risk of becoming cancerous is dysplastic nevus, also called “atypical mole”. They are larger than average (bigger than a pencil eraser) and irregular in shape. Their color can be uneven with dark brown centers and lighter, sometimes reddish, uneven borders or black dots/speckles at the edge. Someone with dysplastic nevi may have a greater-than-average chance of developing malignant melanoma. These people should be seen regularly by a dermatologist to check for any changes that might indicate skin cancer. They should also learn to do regular self-skin exams (see below), looking for changes or new moles. They also need to be more aggressive with sun-protection by using sunscreen and protective clothing.
The most important step you can take is to check your skin. If the appearance of a mole worries you or if it changes suddenly, you should consult a dermatologist.
Use the ABCD’s to monitor changes:
- Asymmetry – One half of the mole doesn’t match the other half.
- Border irregularity – The edges are ragged, notched or blurred.
- Color – The color is not uniform, shades of tan, brown, and black are present (rarely red, white & blue)
- Diameter – The width is greater than six millimeters (size of a pencil eraser) or growing rapidly.
Prevention / Protection
Overexposure to sunlight is the main cause of skin cancers. Although any race can get skin cancers, fair skinned people living in sunny climates have a much higher risk (Arizona has the 2nd highest incidence of skin cancer in the world). Following these steps can help reduce your risk of skin cancer or of getting second skin cancer.
- Seek shade or stay indoors between 10am – 4pm
- Wear light colored, tightly woven protective clothing and wide brim hats (3 inches)
- Apply sunscreen with SPF of at least 15 – 30 to exposed areas. Reapply every hour. (Note: Sunscreens are not perfect and cannot block all the sunrays, so do not use them as an excuse to spend more time in the sun)
- Perform self-skin exams every 3-4 months (see below)
Periodic Self-Examination – Prevention of melanoma/skin cancer is the best weapon against these diseases. But if a melanoma should develop, it is almost always curable if caught in the early stages. Practice periodic self-examination to aid in early recognition of any new or developing lesion. The following is one way of self-examination that will ensure that no area of the body is neglected. To perform your self-examination you will need a full length mirror, a hand mirror and a brightly-lit room.
