The first symptom of a melanoma is usually the appearance of a new spot, or a change in an existing freckle or mole. The change might be in size, shape or colour, and is usually noticed over several weeks or months.
These changes can include:
Colour - A mole may change in colour or have different colour shades or become blotchy.
Size - A mole may appear to get bigger.
Shape - A mole may have in irregular border or may increase in height.
Elevation - The mole may develop a raised area.
Itching or bleeding.
If you have a suspicious spot or mole, the ABCDE guidelines provide a useful way to monitor your skin and detect the early signs of melanoma:
Asymmetry - Half of a mole or birthmark does not match the other.
Border irregularity - Is the spot uneven? The edges are irregular, ragged, notched, or blurred.
Colour variation - The colour is not the same all over, but may have differing shades of brown or black, sometimes with patches of red, white, or blue.
Diameter - The area is larger than 6mm (about the size of a pencil eraser) or is growing larger.
Evolving - Is the spot changing and growing? Changes in size, shape, colour, elevation, or another trait (such as itching, bleeding or crusting). This last point is likely the strongest of all the warning signs.
(Source: Cancer Council Australia, Melanoma Institute Australia)
