The image below shows how the punch biopsy is performed. An injection is administered to numb the skin. A sterile instrument is used to take a 3mm portion of skin from the involved area. The skin is then sent to pathology where it is examined under a microscope to diagnose the condition.

The site where the sample of skin is taken from is covered with a bandaid and will usually heal in 3-4 days. A follow up appointment is made and the pathology report then helps to determine the course of treatment. This very helpful for cases of dry scaly skin that looks like an athlete’s foot infection but is not responding to topical anti fungal creams. These are frequently eczema misdiagnosed as an athlete’s foot infection.