Bad news: Melanoma can make a mole itch even though the mole still looks normal and unchanged.
The itching can come before the mole starts looking different.
You already know that melanoma can make a mole itch. This information is found on many a medical site.
However, those sites fail to mention if, by the time that melanoma causes a mole to itch, the mole is already visibly changed (e.g., darker, bigger, bumps appearing on it, bleeding).
So I decided to ask an esteemed dermatologist if, indeed, melanoma can cause a mole to start itching before it begins changing in appearance.
“Yes, it is possible that a melanoma may make a mole itch before it changes its appearance,” says Sharyn Laughlin, MD, dermatologist and developer of the CyberDERM line of sun protection products and medical director of Laserderm, a pioneering laser skin surgery clinic in Ottawa, Ontario, Canada.
“This would be considered an evolution in the mole as part of the conventional ABCDE’s of abnormal mole development.”
A = asymmetry (new onset)
B = border (change in)
C = color (change in)
D = diameter (increasing)
E = evolving (some other detectable change such as crusting, bleeding, oozing, pigment spilling into surrounding skin, appearance of tiny satellite moles around the main one)
Dr. Laughlin explains, “When a patient comes in with a complaint that a mole has become very itchy, dermatologists take that very seriously.
“Having said that, the majority of melanomas do not start in a mole that you have had for a long time.”
The estimated percentage of melanomas that do begin in a pre-existing, long-time mole is 30 percent.
So while it’s important to be very familiar with your moles, you should also inspect your skin in general as part of your monthly self-screening exams for skin cancer.
Other skin cancers (basal cell carcinoma and squamous cell carcinoma) do not arise from the pigment cells (melanocytes) that comprise the common mole.
However, by coincidence, BCC and SCC (above) can start developing on the skin where a mole just happens to be.
BCC and SCC can cause itching of the part of the skin that they’re growing within.
When melanoma causes a mole to itch, why does this happen?
“There is no clear clinical data to verify the exact mechanism for what makes a mole itch,” says Dr. Laughlin.
“From my 37 years of practice, it would seem a cellular type of inflammation is a factor without any other obvious signs.
“Perhaps it’s the body’s way of alerting us to the fact that something dangerous is evolving — almost like an autoimmune response.
“Another possible explanation is that the melanoma has grown inwards, and there is deeper invasion that now involves an underlying nerve.
“This is usually a late sign and the ABCDE signs would already be present. However, there are plenty of melanomas that present with no clear warning signs or at least things that are not ordinarily perceived as red flags.”
Keep in mind that there are many causes other than melanoma for why a mole would begin itching.
Make a concerted effort to give yourself a monthly skin self-exam — to identify changes in appearance or new lesions — including behind the ears, the bottom of your feet and toes, and other areas where there’s little exposure to the sun.