Share your insights

Help us by sharing what content you've recieved in your exams

Punch biopsy of the skin [advanced]

Please note content is for educational purposes only and procedures should not conducted based on this information. OSCEstop and authors take no responsibility for errors or for the use of any content.


  • Wash hands, Introduce self, Patients name & DOB & wrist band, Explain procedure and get written consent
    • Common risks: scarring, bleeding, infection, damage to local structures, nerve damage, numbness over area

Preparation part

  • Wash hands and apply apron
  • Clean a trolley
  • Gather equipment onto bottom of trolley (think through what you need in order)

Equipment list

  • Sterile pack
  • Cleansing snap-sponge (iodine or alcohol/chlorhexidine)
  • Sterile drape with hole in centre (or 2-3 drapes without holes in)
  • 5ml syringe and 2 needles (1 blunt fill 18G drawing-up needle, 1 orange 25G) for local anaesthetic
  • 4mm sterile disposable biopsy punch x1-3
  • Suturing instrument kit
    • Needle holder
    • Toothed forceps
    • Non-toothed forceps
    • Scissors
  • 4-0 Novafil suture (or similar)
  • Cotton gauze swabs (used whenever needed throughout procedure to dry/clean sterile area)
  • Sterile dressing
  • Equipment to be kept outside the sterile field
    • 10ml sterile saline
    • Sterile gloves
    • 5ml 1% lidocaine (maximum 3mg/kg – note 1ml 1% lidocaine = 10mg) with or without adrenaline
    • Sample tubes
      • Formalin filled specimen container for histology (must send white page of consent form with this sample)
      • Direct immunofluorescence sample container for direct immunofluorescence (if required, e.g. for bullous disorders, vasculitis, or connective tissue diseases; this sample should be from perilesional skin for bullous lesions; skin punch is wrapped in small part of saline soaked gauze inside tube)
      • White top universal container for microbiology (if required, e.g. for suspected infection)

  • Walk to patient
  • Wash hands
  • Open sterile pack to form a sterile field on the top of the trolley
  • Open packets (without touching the instruments themselves) and drop sterile instruments neatly into the sterile field
  • Pour some sterile saline over a gauze so it is moist
  • Pick up waste bag from sterile pack without touching anything else and stick to side of trolley

Patient part

Positioning and exposure

  • Choose and expose biopsy site
    • Ideal areas: arms, thighs, back, abdomen
    • Ideally biopsy an established lesion with the most primary inflammatory change (unless blistering/pustular/vasculitic lesion, then early lesions preferred)
    • Part of lesion to biopsy
      • For large lesions, biopsy the edge of the lesion, the thickest part, or the most abnormal area
      • For annular lesions, biopsy the edge of the lesion
      • For ulcers, biopsy the edge and include a portion of normal skin
      • NB. in bullous skin lesions, the skin biopsy for direct immunofluorescence should be taken from perilesional skin.
    • Areas to avoid if possible
      • Sites with underlying nerves or blood vessels
      • Cosmetic-sensitive areas (e.g. face; shoulders and chest are prone to hypertrophic scarring)
      • Areas with high infection risk (e.g. groins, axillae)
      • Areas of vascular insufficiency (e.g. lower legs/feet)
      • Lesions with secondary features (e.g. infection/crusting)
      • Lesions that have been subjected to trauma (e.g. scratched lesions, lesions over joints)
  • Position patient comfortably
  • Mark biopsy site(s) with a skin pen/indentation


  • Wash hands
  • Apply sterile gloves using sterile technique (open pack on a side surface)
  • Sterilize area
    • Work from middle outwards in one spiral motion (use cleansing snap-sponge)
    • Discard used snap-sponge as it is no longer sterile, but note all equipment used after this (including all needles) can be returned to the sterile field after use
    • Apply the sterile drape over the site so that the hole is in the correct place to allow access to the biopsy site
  • Anaesthetise area
    • Ask assistant to snap open lidocaine bottle and hold open upside-down
    • Draw up lidocaine using drawing-up needle on 5ml syringe
    • Change to the orange needle and insert at an acute angle to anaesthetise the area of the biopsy site (subcutaneously and slightly deeper; 1-2ml per biopsy site)

Performing the punch biopsy

  • Stretch skin perpendicular to resting skin lines
  • Push biopsy punch directly into skin, rotating it back and forth, as far as it will go (should go through to subcutaneous fat – a β€˜giving way’ feeling marks this point)
  • NB. in areas of thin skin, do not go down as far as the periosteum. Avoid areas with underlying nerves or blood vessels.
  • Remove biopsy punch
  • Press down on either side to elevate skin punch
  • Grab skin punch very gently with toothed forceps (avoid crush injury), elevate, and cut off at the base with scissors
  • Place skin punch on saline soaked gauze in sterile field
  • Suture wound with a single suture (parallel to skin tension lines) – see suturing notes
  • NB: leave enough thread on the needle end if need multiple biopsies
  • Repeat process if multiple biopsies required (different biopsy required for histology, direct immunofluorescence, and microbiology if required)
  • Apply a sterile dressing
  • Place samples in specimen tubes as detailed below

To complete

  • Thank patient and cover them
  • Bin waste and gloves, dispose of sharps safely, clean trolley and wash hands
  • Label tubes and send to lab, listed as urgent if rapid result required
    • Formalin sample tube (histology) β†’ histopathology
      • Must be sent with white page of patient consent form
    • Direct immunofluorescence sample tube (direct immunofluorescence)β†’ histopathology (if required)
      • Skin punch for this sample should be wrapped in a small part of saline soaked gauze (cut off with scissors)
    • White universal sample tube (MC&S) β†’ microbiology (if required)
  • Advice patient sutures must be removed in 10-14 days
  • Fully document procedure in patients notes

No comments yet πŸ˜‰

Comments are closed for this post.