Your doctor can take a diagnostic sample from your skin in case he or she would like to have further tests done to establish what caused your lesion or rash. This article discusses some of the common techniques that can be used to take that sample so a pathologist can conduct further tests.
Excision biopsy refers to a method of taking a tissue sample by removing an entire lesion or area affected by a rash. The doctor uses a scalpel to cut out the lesion. That sample will also include some parts of the normal skin around the affected area. This technique is usually used in case the doctor suspects that you could be suffering from skin cancer.
Incision biopsy involves the partial removal of a lesion or section of skin affected by a rash. Just as in excision biopsy, the doctor also uses a scalpel to cut out a segment of the affected tissue on your skin. This technique is usually used when the doctor does not suspect that you could be having skin cancer. The specimen taken usually includes segments of normal skin so that the affected skin can be compared to the surrounding tissues.
Punch biopsy can also be used to remove a small part of a lesion on your skin. The technique involves the use of a punch scalpel. A punch scalpel looks like a tube with a sharp edge. The sharp edge is inserted or twisted against the affected skin on your body. The doctor then uses a scalpel to separate the skin inside the punch scalpel from your body. This technique is normally used when a small sample is needed from a big lesion or area affected by a rash.
Shave biopsy involves the removal of the surface layers of a lesion or area affected by a skin rash. The doctor uses forceps to lift the skin where the lesion is located. Next, he or she uses a scalpel to cut or shave off the top layers of the affected skin. This technique may not remove the entire lesion. It is also not used in case you are suspected to be having skin cancer. This is because the method does not allow the pathologist to know how deep the lesion has grown.
Each of the techniques above has pros and cons. It is therefore advisable for you to discuss skin biopsy options with your doctor so that he or she recommends the most appropriate one for your condition. The doctor will also take any necessary measures, such as the use of a local anaesthetic, in order to protect you from pain during the procedure.