Table of Contents IntroductionPreparation partPatient partPositioning and exposurePreparationPerforming the punch biopsyTo complete Introduction Wash hands, Introduce self, Patients name & DOB & wrist band, Explain procedure and get written consentCommon risks: scarring, bleeding, infection, damage to local structures, nerve damage, numbness over area Preparation part Wash hands and apply apronClean a trolleyGather equipment onto bottom of trolley (think through what you need in order) Equipment list Sterile packCleansing 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 anaesthetic4mm sterile disposable biopsy punch x1-3Suturing instrument kitNeedle holderToothed forcepsNon-toothed forcepsScissors4-0 Novafil suture (or similar)Cotton gauze swabs (used whenever needed throughout procedure to dry/clean sterile area)Sterile dressingEquipment to be kept outside of the sterile field10ml sterile salineSterile gloves5ml 1% lidocaine (maximum 3mg/kg – note 1ml 1% lidocaine = 10mg) with or without adrenalineSample tubesFormalin 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 patientWash handsOpen sterile pack to form a sterile field on the top of the trolleyOpen packets (without touching the instruments themselves) and drop sterile instruments neatly into the sterile fieldPour some sterile saline over a gauze so it is moistPick 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 siteIdeal areas: arms, thighs, back, abdomenIdeally biopsy an established lesion with the most primary inflammatory change (unless blistering/pustular/vasculitic lesion, then early lesions preferred)Part of lesion to biopsyFor large lesions, biopsy the edge of the lesion, the thickest part, or the most abnormal areaFor annular lesions, biopsy the edge of the lesionFor ulcers, biopsy the edge and include a portion of normal skinNB. in bullous skin lesions, the skin biopsy for direct immunofluorescence should be taken from perilesional skin.Areas to avoid if possibleSites with underlying nerves or blood vesselsCosmetic-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 comfortablyMark biopsy site(s) with a skin pen/indentation Preparation Wash handsApply sterile gloves using sterile technique (open pack on a side surface)Sterilize areaWork 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 useApply the sterile drape over the site so that the hole is in the correct place to allow access to the biopsy siteAnaesthetise areaAsk assistant to snap open lidocaine bottle and hold open upside-downDraw up lidocaine using drawing-up needle on 5ml syringeChange 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 linesPush biopsy punch directly into skin, rotating it back and forth, as far as it will go (should go through to subcutaneous fat – a ‘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 punchPress down on either side to elevate skin punchGrab skin punch very gently with toothed forceps (avoid crush injury), elevate, and cut off at the base with scissorsPlace skin punch on saline soaked gauze in sterile fieldSuture wound with a single suture (parallel to skin tension lines) – see suturing notesNB: leave enough thread on the needle end if need multiple biopsiesRepeat process if multiple biopsies required (different biopsy required for histology, direct immunofluorescence, and microbiology if required)Apply a sterile dressingPlace samples in specimen tubes as detailed below To complete Thank patient and cover themBin waste and gloves, dispose of sharps safely, clean trolley and wash handsLabel tubes and send to lab, listed as urgent if rapid result requiredFormalin sample tube (histology) → histopathologyMust be sent with white page of patient consent formDirect immunofluorescence sample tube (direct immunofluorescence) → 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) → microbiology (if required)Advice patient sutures must be removed in 10-14 daysFully document procedure in patients notes