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.
Symptoms of Necrotic Wounds. There are two main types of necrotic tissue present in wounds: eschar and slough. Eschar presents as dry, thick, leathery tissue that is often tan, brown or black. Slough is characterized as being yellow, tan, green or brown in color and may be moist, loose and stringy in appearance. Etiology.