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The Skin on Your Arms: A Practical Guide to Monitoring Flat Spots

By Michael C. · Written and reviewed by Michael C.

UV Protection · Published 2026-09-25 · 10 min read · 1305 words · Updated 2026-10-02

That new flat spot on your arm is usually harmless, but here is how to tell the difference between a simple sun spot and something that needs a doctor.

Key takeaways

  • Most flat spots on the arm are harmless sun spots, but any new or changing spot should be checked by a professional.
  • Use the ABCDE rule to monitor for asymmetry, irregular borders, multiple colours, large diameter, and evolution.
  • The Skin Cancer Foundation of South Africa offers free screenings every September to help with early detection.
  • Daily application of SPF 30+ is the most effective way to prevent further sun damage and pigment changes.

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Source: scanskinai.com (https://www.scanskinai.com/spot-on/arm-flat-spot)

Cover image: Grove Brands — credit