Slough is typically a white / yellow colour. It can be found in patches or it can cover large areas of the wound. It is made up of dead cells which have accumulated in the exudate. It may be related to the end of the inflammatory stage in the healing process, and for healing to take place it is advised that slough is removed.
An infected wound is characterised by a green / yellow discharge (purulent) and may have an offensive smell. Usually there is localised redness (erythema). There may be localized pain and a raised temperature.
This tissue is usually black in appearance and forms a hard scab on the tissue which becomes ischaemic and dead. The scab (eschar) may mask the true size of the wound below. Unless the necrotic tissue is removed the wound will continue to increase in size.