Elizabeth Martin and Robert Hine. Latest Edition (7 ed.) Fully revised and updated, the sixth edition of this dictionary provides comprehensive coverage of biology, biophysics, and biochemistry, as well as key terms from medicine and palaeontology.
For example, if someone scratches a mole until it bleeds, the resulting lesion, a crust, is now a secondary skin lesion. The most common secondary skin lesions include: 1  crust: a crust, or a scab, is created when dried blood forms over a scratched and irritated skin lesion. 2  ulcer: typically caused by a bacterial infection or physical trauma. 3  scale: patches of skin cells that build up and then fall off the skin.
A blood blister is a specific type of blister that is due to damage to blood vessels and tissues just under the skin, which causes blood and other fluids to pool and form a bump.Blood blisters typically form after a strong pinch of the tissues, but there are other causes as well. blood blister is a specific type of blister that is due to damage to blood vessels and tissues just under the skin, which causes blood and other fluids to pool and form a bump.