I always tell friends and family that worrying doesn’t change the outcome; it only adds stress.
The same goes for your skin. If a spot is bothering you, the best move is to have a dermatologist look at it rather than lie awake wondering. Still, not all spots are created equal. Some growths that look like a harmless bug bite turn out to be skin cancer, and plenty of scary-looking spots turn out to be nothing at all.
So, how do you tell the difference?
Start with a self-check
Before we get to what to look for, you need to know how to look.
Monthly skin checks are ideal, but honestly, checking whenever you remember is far better than never checking at all. Use good lighting and a hand mirror (or a partner) for the areas you can’t see, like your back and scalp. Don’t skip the places people forget: between your toes, the soles of your feet, under your nails and the genital area. Skin that never sees the sun can still develop dangerous growths.
In training, dermatologists are taught to perform a skin exam the same way, in the same order, every time. I’d give you the same advice. Pick a routine, such as head to toe and front to back, and stick with it so nothing gets missed.
The three main skin cancers
Basal cell carcinoma (BCC) is the most common skin cancer and the least dangerous. Think of it like a bad spot on an apple or a cavity in a tooth: it rarely spreads elsewhere in the body, but it keeps growing if left alone.
That’s a common theme with skin cancers. If a spot goes away on its own, a dermatologist usually isn’t worried about cancer. BCC often looks like a small pink or pearly bump, or a sore that bleeds, scabs over, and keeps coming back. Many people mistake it for a pimple.
Here’s my rule of thumb: a “pimple” that has been around for months probably isn’t a pimple, and it should be looked at.
Squamous cell carcinoma (pronounced SKWAY-mus, or SCC) is common in people who spend years enjoying the sun without much protection. Many start as an actinic keratosis, or “AK.” If a dermatologist has ever frozen off “precancers” for you, those were likely AKs. They feel like rough, sandpapery patches, and a small number of them turn into SCC over time.
SCC can also look a lot like a BCC, which is why we biopsy. As I covered in an earlier column, knowing exactly what we’re treating matters.
Melanoma is the most serious of the three. People often think of it as a “bad mole,” but most melanomas actually appear as a new spot rather than growing out of an existing mole. That doesn’t mean every new mole is a problem. But new moles become less common as we get older, so one that shows up in adulthood deserves a closer look.
So when should you be concerned?
For BCC, watch for a pink or skin-colored bump that is new and slowly growing over weeks to months. A bump that pops up for a few days and then fades is much less concerning. If it has been there a month or longer, especially if it bleeds on its own or hurts, get it checked.
For SCC, watch for any rough patch or bump on sun-exposed skin (even if that sun exposure was decades ago) that has lasted more than a month. Tenderness, bleeding without being bumped, or an odd sensation, which some patients compare to a splinter, are all red flags.
Melanoma is trickier, but dermatologists rely on a simple memory aid called the ABCDEs:
A is for Asymmetry. One half of the spot doesn’t match the other. A normal mole is usually a mirror image of itself.
B is for Border. Jagged, blurry, or scalloped edges are concerning. Normal moles have smooth, even borders.
C is for Color. Several different colors in one mole, especially red, white or blue, are a reason to have it checked.
D is for Diameter. Anything larger than about 6 millimeters, roughly the size of a pencil eraser. Melanomas can be smaller, though, so a small size alone doesn’t clear a spot.
E is for Evolving. Any mole that changes in size, shape or color, or starts to itch, bleed or crust, always warrants a visit.
One bonus rule is what we call the “ugly duckling” sign. Most people’s moles share a family resemblance. If one looks different from all the rest, have it checked, even if it passes the ABCDEs.
Keep in mind that every one of these rules has exceptions. This is a general framework, not a substitute for an exam.
The bottom line
If a spot on your skin concerns you, see a dermatologist. No question is too small; answering them is what we’re here for. Worrying won’t change the outcome, but getting it checked might.
Have a skin question you’d like answered in a future column? Email it to skindermatologypv@gmail.com.
Dr. Mitch Brady, DO, is a board-certified dermatologist (American Board of Dermatology) practicing in Ponte Vedra Beach.
