When to refer a mole: red flags for GPs

Refer a pigmented lesion when it shows any ABCDE feature (asymmetry, border irregularity, colour variation, diameter over 6 mm, evolution), when it stands out from the patient's other moles, or when the history includes change, bleeding, or new onset after age 40. When in doubt, a same-day specialist opinion beats watchful waiting.

The stakes

South Africa has high cutaneous melanoma rates in fair-skinned populations, and outcomes are strongly stage-dependent. The GP consultation is where most melanomas are first surfaced — usually as a "by the way, doctor" at the end of an unrelated visit. A structured way of deciding refer now / get an opinion / safe to monitor is worth having ready.

ABCDE — the classic screen

• A — Asymmetry: one half does not match the other.
• B — Border: irregular, scalloped, or poorly defined edges.
• C — Colour: more than one shade — browns, black, red, white, or blue within one lesion.
• D — Diameter: larger than 6 mm (pencil-eraser size), though melanomas can be smaller.
• E — Evolution: any change in size, shape, colour, elevation, or symptoms. Evolution is the most important single feature.

Any one positive feature should prompt a closer look; two or more should lower your referral threshold sharply.

The ugly duckling sign

Most people's moles resemble each other. A lesion that looks different from the patient's other naevi — darker, larger, more irregular — deserves attention even if it doesn't tick a textbook ABCDE box. In patients with many atypical naevi, the ugly duckling comparison often outperforms criteria applied lesion-by-lesion.

History features that raise the stakes

• A new pigmented lesion appearing after age 40.
• Itching, bleeding, or crusting in a mole without trauma.
• Personal or family history of melanoma.
• High lifetime sun exposure, blistering sunburns in childhood, or immunosuppression.
• Patient-reported change — take "it looks different to me" seriously; patients are often right.

Special situations worth a low threshold

• Acral lesions — pigmented streaks on palms, soles, or under nails (especially new, broad, or irregular nail streaks) warrant specialist review in all skin types. Acral melanoma is the dominant subtype in patients with darker skin and is diagnosed late disproportionately often.
• Amelanotic lesions — a growing pink or flesh-coloured papule can be melanoma without pigment. Growth is the clue.
• Nodular change — a firm, growing nodule within or beside an existing mole.

What to tell the patient while they wait

If you refer or request a specialist opinion, advise the patient not to traumatise the lesion, to photograph it for comparison, and to return immediately if it changes visibly. Document your examination — including a photo with a size reference — in the patient file.

The bottom line

No single rule replaces clinical judgement, but the combination of ABCDE, the ugly duckling sign, and a focused history catches the large majority of lesions that need a specialist. When the picture is ambiguous, a rapid teledermatology opinion converts uncertainty into a documented plan — usually the same business day.