The word “biopsy” can sound frightening because people associate it only with cancer. In dermatology, biopsy simply means taking a small sample of skin for examination under a microscope. It is used for many inflammatory, infectious and other skin conditions when the diagnosis is unclear from appearance alone.
When a biopsy may be useful
A dermatologist may consider biopsy for an unusual persistent rash, a growth with concerning features, suspected autoimmune or blistering disease, or when several conditions look similar clinically but require different treatment. It is not necessary for every mole or every rash.
What happens
The area is cleaned and numbed with local anaesthetic. The sampling method depends on the lesion and question being asked. Some biopsies need a stitch; others may not. You should receive wound-care instructions and an explanation of when results are expected.
The laboratory needs the clinical story too
Pathology is most useful when the dermatologist sends the right site and clinical differential diagnosis. Sometimes a biopsy narrows possibilities rather than giving a single one-word answer, so the result is interpreted alongside the examination.
Related clinic page: Dermatological Surgery