DEAR MAYO CLINIC: My doctor suggested I get a yearly skin check by a dermatologist to check for melanoma. Why is this necessary? I am almost 50 and have never had any suspicious moles or spots.

ANSWER: It’s a good idea to be evaluated by a dermatologist once a year. In addition, checking your skin at home regularly will make it more likely that melanoma and other types of skin cancer are caught early. The sooner skin cancer is found, the better the chances are of curing it.

Melanoma is the most serious type of skin cancer. It develops in cells called melanocytes that produce melanin—the pigment that gives your skin its color. The exact cause of all melanomas isn’t clear, but exposure to ultraviolet, or UV, radiation increases your risk of developing the disease. This can come from sunlight, as well as from tanning lamps and beds.

The number of melanoma cases has increased dramatically over the past 30 years, especially in middle-age women. The increase may be linked to the rise of tanning bed use in the 1980s, when many women who are now in their 40s and 50s were in their teens.

Melanoma that goes unchecked and spreads can be difficult to treat. But when it’s caught early, melanoma often is curable. That’s why it’s so important to be familiar with your skin and report any changes to your dermatologist right away, especially if you’ve had a significant amount of exposure to tanning beds in the past. Get into the habit of checking your skin once a month. In particular, watch for moles appearing that haven’t been there before.

Know the ABCs of skin cancer, too, and report any of them to your dermatologist. “A” is for asymmetry: One half of a mole looks different from the other half. “B” is border: The borders of a mole are uneven, jagged, or scalloped. “C” is for color: The color of a mole is different from one area to another. Specifically, if you see colors of the US flag—red, white, or blue—within a mole, that can be a concerning change.

It’s also important to note a mole’s size. If you have a mole larger than about one-quarter of an inch across—or about the size of a pencil eraser—have it checked. If there is a change in the size, shape, or color of a mole, or if you develop symptoms such as bleeding, itching, or tenderness, that should be evaluated, as well.

Other kinds of skin cancer that a dermatologist will be looking for include basal cell carcinoma and squamous cell carcinoma. These cancers tend to look like pink, red, or scaly spots on your skin that do not go away on their own.

An annual skin check from a dermatologist often only takes a few minutes, but it is a critical part of catching skin cancer early. Dermatologists specialize in skin disorders and often can spot problem areas on the skin quickly. That’s particularly true after you have your first skin assessment, which may take a little longer than follow-up visits.

Of course, prevention is also key. Protect your skin as much as possible. Stay out of the sun during the middle of the day when UV light is the strongest. But when you are outdoors, use sunscreen no matter the season or weather. The sun protection factor, or SPF, of your sunscreen should be at least 30, and sunscreen should be applied generously and frequently to get the full amount of protection. Never use a tanning light or tanning bed, as they can drastically increase your chances of melanoma.

— Dr. Jerry Brewer, Dermatology, Mayo Clinic, Rochester, MN