Skin biopsy is a biopsy technique in which a skin lesion is removed to be sent to a pathologist to render a microscopic diagnosis. It is usually done under local anesthetic and results are often available in 4 to 10 days.
A punch biopsy takes a core (a small cylindrical fragment of tissue from the area of interest) and can be used to diagnose rashes and other conditions. Excisions are usually larger and deeper and are used to completely remove an abnormal area of skin such as a skin cancer.