Describe how a punch biopsy should be performed.

After anesthetizing and prepping the surgical site, the circular blade of the punch is placed over the lesion at 90 degrees to the skin surface. The handle of the punch is gently held between thumb and forefinger, and the blade is rotated in a fairly rapidly alternating clockwise, anticlockwise fashion, while maintaining skin tautness across the biopsy site using thumb and index finger. Initially, very little downward pressure should be applied to the punch while the punch’s blade is still at the level of the epidermis, to prevent shearing of the epidermis from the dermis, which makes histologic examination difficult. Continue until the hub of the punch reaches the level of the skin. In certain anatomic sites with important superficial nerves and vessels, be careful not to hub the punch. Now remove the punch.