What Is the ABCDE Rule for Detecting Melanoma?

You probably don’t think twice about a freckle or mole. Many people have them, and they rarely change. But sometimes, even a subtle shift in your skin could be the first warning sign of melanoma. Knowing what to watch for—and acting quickly—can make all the difference. 

That’s where the ABCDE rule comes in.

What Is the ABCDE Rule?

The ABCDE rule helps you spot early signs of melanoma by evaluating moles or skin spots using five key criteria:

A – Asymmetry

One half of the mole doesn’t match the other. Symmetry is a good sign, so it’s worth checking when a mole looks lopsided.

B – Border

Typical moles have smooth, defined edges. It could be a warning sign if the border is irregular, notched, or blurred.

C – Color

Healthy moles tend to be a single shade. Multiple colors or uneven tones, like black, brown, tan, red, white, or blue, could signal melanoma.

D – Diameter

Watch for moles larger than six mm, about the size of a pencil eraser. Melanomas can be smaller, but size can still offer an early clue.

E – Evolving

If a mole changes in shape, size, color, or starts to itch, bleed, or crust, don’t ignore it. Change is one of the most important signs.

Why Early Detection Matters

Catching melanoma early gives you the best chance of successful treatment. Once it spreads, it becomes more difficult to treat. The challenge is that early-stage melanoma often doesn’t hurt or cause discomfort. That’s why regular self-checks and professional skin exams are essential for staying ahead of it.

When to See a Dermatologist

If something on your skin seems new or unusual, it’s time to get it checked. Even if it turns out harmless, it’s better to be cautious. A dermatologist can examine your skin more closely, using tools like dermoscopy or performing a biopsy if needed. It’s a simple step that could have significant impact.

At Westchester Cosmetic Dermatology, we provide complete skin checks and clear guidance if something needs follow-up. Dr. David Kriegel leads our team and was named one of New York’s top doctors in 2024 by his peers through the MSP Communications selection process, with recognition published in New York Super Doctors in The New York Times Sunday Magazine on May 4, 2025.

Schedule Your Skin Check in Westchester

Skin cancer doesn’t wait—and neither should you. If a mole looks different or a spot seems off, schedule a visit with a dermatologist. At Westchester Cosmetic Dermatology, we’re here to guide you through early detection and treatment. Taking one step today could protect your health for years to come.