Other things that should be checked by a doctor include sores that don't heal, unexplained skin ulcers and new or existing moles larger than 6mm in diameter.

Even if they don't, they can cause disfiguring skin ulcers.

The skin ulcers particularly on the legs could possibly not entirely heal, which can cause difficulties that could lead to infection and amputation.

The severity of these skin lesions normally begins during childhood, and may span from a mild rash to skin ulcers that are more severe.

If skin ulcers become badly infected or develop gangrene, they often require amputation.