Prepare the lesion and surrounding skin with antiseptic solution.

Anesthetize the site with lidocaine 1% with or without epinephrine (1:100,000). Do not use epinephrine on the digits or on the tip of the penis. It is safe, however, on the nasal tip and ears. Epinephrine can reduce bleeding and make visualization of the lesion easier. The anesthetic effect may be almost immediate, but it is best to wait 3 to 5 minutes before proceeding with the biopsy. The full hemostatic effect takes somewhat longer to occur and helps to maintain hemostasis after the procedure.

Select the proper punch size. The size depends on the size of the lesion, how much of the lesion (or dermatitis) must be removed to make the histologic diagnosis, its anatomic location, and the differential diagnosis. Punches of 3 and 4-mm diameter are used most often. Disposable punches are reliably sharper than reusable instruments.