What are the red flags for concerning skin lesions?

Melanoma

The ABCDE criteria remain the primary framework:

Evolution is considered the strongest single warning sign.

Nodular melanoma

Often doesn't follow ABCDE. Use the EFG criteria instead:

• Elevated above skin surface
• Firm to the touch
• Growing rapidly (over days to weeks)

This is one of the most dangerous subtypes and can be symmetrical, uniform in colour, and small in diameter, meaning it is easily missed.

Other melanoma red flags

• Dark-brown or black vertical line beneath a fingernail or toenail
• A new spot appearing after age 25
• The "ugly duckling" sign: a mole that looks different from all others

Basal Cell Carcinoma (BCC)

• Pearly or translucent bump, possibly with visible telangiectasia
• Non-healing sore that bleeds, crusts, then recurs
• A lesion resembling a scar (white, waxy, or yellow) without history of trauma

Squamous Cell Carcinoma (SCC)

• Persistent scaly red patch or plaque, especially on sun-exposed areas (head, neck, dorsum of hands)
• Firm, raised growth that may bleed
• Tenderness or pain at the lesion site

When to Act

Any lesion demonstrating one or more of these features warrants further assessment, ideally supplemented by dermoscopy, which is the standard of care for evaluating suspicious lesions in Australian general practice. Excision biopsy with a 2 mm margin is recommended for lesions clinically suspicious of melanoma.