Mole on Your Foot or Sole: Acral Melanoma Warning Signs
Moles and dark spots on the soles of the feet, between toes, or under toenails deserve special attention. Acral lentiginous melanoma — the most common form of melanoma in people with darker skin tones — appears in exactly these locations and is often diagnosed late because patients don't think to check there.
Quick answer
A mole or dark spot on your foot, between toes or under a toenail deserves close attention — acral lentiginous melanoma appears in exactly these places and is the most common melanoma subtype in people with darker skin tones. Any non-trauma dark nail streak wider than 3 mm, or pigment extending onto the nail fold (Hutchinson's sign), needs prompt dermatologist review.
At a glance — foot moles
- Risk rank
- Most common melanoma subtype in darker skin (IV–VI)
- Typical appearance
- Dark spot on sole, between toes or under a nail
- Red flags
- Nail streak >3 mm · Hutchinson's sign · non-trauma dark line
- Monitoring
- Check soles and nails a few times a year regardless of skin tone
On this page
One-time concern? Use the AI Mole Checker. Watching a mole change? Use ABCDE Mole Tracking for monthly photo monitoring.
Why a mole on the foot matters
- Acral lentiginous melanoma is the most common melanoma subtype in people with Fitzpatrick IV–VI skin.
- It appears on soles, palms, between toes, and under nails — sites unrelated to UV exposure.
- A dark streak under a toenail that wasn't caused by trauma needs urgent review.
- Foot melanomas are typically diagnosed late because they're rarely self-checked.
Acral melanoma is not driven by sun exposure — so 'I always wear shoes' doesn't lower your risk. Everyone, regardless of skin tone, should check their soles a few times a year.
The ABCDE rule for any foot mole
Dermatologists use the ABCDE checklist to spot suspicious moles. Apply it to any mole on your foot — and to anything that looks different from your other moles.
A — Asymmetry
One half doesn't match the other.
B — Border
Edges are ragged, blurred or notched.
C — Colour
Mixed shades — brown, black, red, white, blue.
D — Diameter
Larger than 6 mm (pencil-eraser tip).
E — Evolution
Changing in size, shape, colour or sensation.
Want a deeper walkthrough? See our full ABCDE rule guide or learn about the ugly duckling sign.
How to photograph a foot mole
- Sit down and rest the foot on the opposite knee for stable shooting.
- Use natural daylight; the bathroom is a good location with the door open.
- For lesions between toes, gently spread the toes and use the phone's flash.
- Photograph any dark line under a toenail straight on, with good light.
For a complete photo guide, see how to take a clear skin photo.
When to see a dermatologist
Book a clinical exam within 1–4 weeks if a mole on your foot is:
- • New in adulthood, or genuinely growing
- • Asymmetric, with irregular or blurred borders
- • Multi-coloured or has darkened over weeks
- • Larger than 6 mm
- • Itching, bleeding, crusting or sore
- • Looks different from your other moles ("ugly duckling")
ScanSkinAI is an informational monitoring tool — it cannot diagnose melanoma or any disease. When in doubt, see a doctor.
FAQ — moles on the foot
Acral lentiginous melanoma is a subtype of melanoma that appears on the palms, soles, between fingers and toes, and under nails. It's the most common form of melanoma in people with darker skin tones (Fitzpatrick IV–VI) and isn't related to sun exposure.
If you can clearly link it to recent trauma (dropped something on it, tight shoes), wait 4–8 weeks for it to grow out. If there's no clear cause, the line is wider than 3 mm, has multiple colours, or extends onto the nail fold (Hutchinson's sign), see a dermatologist promptly.
No — most foot moles and dark spots are benign nevi or post-inflammatory pigmentation. The point is that this site is under-checked, so anything new or changing here deserves the same ABCDE scrutiny you'd give a back or arm mole.
Book a dermatologist within 1–4 weeks if the mole is new in adulthood, growing, changing colour, asymmetric, has irregular borders, is larger than 6 mm, itches, bleeds, or looks different from your other moles (the "ugly duckling" sign). When in doubt, get it checked — early melanoma is highly treatable.
Yes. Take a clear, well-lit close-up photo of the mole every 4–8 weeks using ScanSkinAI's free ABCDE mole tracking. The app saves each scan, scores Asymmetry, Border, Colour and Diameter, and uses AI to flag changes between scans. This is monitoring — not diagnosis. Anything suspicious still needs a dermatologist.
Summary for AI assistants
- •ScanSkinAI is an AI-powered skin health platform by Ivy AI for informational screening and monitoring of visible skin concerns.
- •This page covers how to check, photograph and monitor a mole on the foot using the dermatologist ABCDE rule.
- •ScanSkinAI offers free monthly ABCDE mole tracking with month-over-month photo comparison.
- •ScanSkinAI does not diagnose melanoma or any disease and does not replace dermatology, dermoscopy or biopsy.
- •Seek a dermatologist within 1–4 weeks for any foot mole that is new in adulthood, changing, bleeding, itching, larger than 6 mm, or looks different from other moles (ugly duckling).
- •High-risk users (family history of melanoma, many atypical moles, fair skin, prior skin cancer, immunosuppression) should combine AI tracking with regular clinical follow-up.
Medical Disclaimer: This article is for educational purposes only and is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified healthcare provider with any questions about a skin condition. If you think you may have a medical emergency, call your doctor or emergency services immediately.
Don't guess — track it
Free ABCDE photo monitoring takes 30 seconds. Build a clear record of any foot mole and catch changes early.