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Introduction
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 β 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
Preparation
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 β a βgiving wayβ 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) β 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)
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