Unlike other cancers, skin cancer can be seen with the naked eye. For non-melanoma skin cancer, if you have a lesion for more than a month, it’s important to seek medical attention from a dermatologist. A pimple should be gone in three or four weeks. So if a pimple-like sore appears for longer than that, it could be cancer. Also, if it’s itching or bleeding, a dermatologist should check it. Melanoma skin cancer often develops in a preexisting mole. So if you’ve had a mole for a long while that suddenly becomes itchy and sensitive, it may be cancerous. Dermatologists rely on the ABCs of melanoma. They look to see if it has asymmetry, meaning it isn’t the same all around. They look at the border, to see if it’s growing. They look at the color and the diameter, and they look to see if it’s evolving over time. Regular skin checks by your doctor are important, because they can document any moles you have and monitor if any of these changes are happening. Other conditions also can appear to look like skin cancer, such as normal moles, infections, pre-cancer, and more. A board certified dermatologist can determine what is happening with any changes to your skin.