Dermatology Facts

Dermatology Facts—Skin Biopsy


A skin biopsy allows the doctor to examine a very small piece of tissue under the microscope to determine the most appropriate diagnosis and the best treatment for the skin condition. A local anesthetic, similar to the kind that your dentist uses when he fills a cavity, is injected with a very small needle into the skin area to be tested. The skin and tissue underneath is now "asleep" or numb and no pain is felt. A blade may be used to shave off a tiny piece of skin. Alternatively, an instrument shaped like a tiny cookie cutter (punch biopsy instrument) is used to cut a small round piece of tissue and skin from the area. A slight amount of bleeding may occur. Usually, a stitch (suture) is used to close the wound and minimize scarring.

Antibiotic ointment and a band-aid are then applied to the area, and the test is finished. Stitches should be removed in seven to fourteen days, as advised by your physician.

Keep the biopsy area dry for 24 hours and covered with a Band-Aid. If a small amount of bleeding is noticed, place a clean cloth over the area and apply firm pressure for ten minutes. Should the bleeding become heavier or not stop, call office (707-545-4537) and ask to speak with the dermatologist. The area may become wet after 24 hours, but avoid direct pressure from a shower, etc. Apply the antibiotic ointment once a day and keep the site covered with a band-aid. A small scab will form and fall off by itself when the area is completely healed. If any discomfort occurs after the local anesthetic wears off, acetaminophen (e.g., Tylenol) may be given.