The most important warning sign for melanoma is a new spot on the skin or a spot that has changed in size, shape, or colour. Another sign is a spot that looks different from all other spots on the skin. One way of checking your skin is by following the ABCDE rule. If you have any of these warning signs, have your skin checked by a doctor as a precaution.
The ABCDE rule:
The appearance of a dark spot that has one side different to the other.
A spot with an irregular, wavy, uneven border that is clearly defined against the surrounding skin.
A spot with an uneven colour. This may include shades of brown or black, or sometimes with patches of pink, red, white, or blue.
A spot that is greater than 6mm in diameter.
Any dark spot that has changed rapidly in size, colour or thickness.
Although some spots with these characteristics indicate melanoma, not all melanoma show these characteristics.