Dermatologists want to raise the alarm on non-pigmented melanomas after new research confirmed red melanomas are more aggressive than common cancers.

Dermatologists and patients are being urged to look out for red spots because they could be a type of melanoma that is more aggressive than cancers associated with black or brown moles.

The Victorian Melanoma Service wants to raise the alarm on non-pigmented melanomas based on recent research that confirms red melanomas are more invasive, grow faster and are more likely to be life-threatening.

"We have always known that red melanomas existed, however we are only now realising that these cause more deaths and are frequently overlooked," John Kelly says.

Associate Professor Kelly says examining melanomas that do not have typical pigmentation is vital to identifying the subtype and the treatment they require.

"The current issue we face is these melanomas are harder to identify because they lack the variation in colours and depth of colour seen in common melanomas," he said.

Professor Kelly hopes improving awareness and educating clinicians will lead to better detection and prevent misdiagnosis.

He is a speaker at the annual scientific meeting of the Australasian College of Dermatologists.