Common skin lesions


Originally developed for the University of Auckland Goodfellow Unit in 2007. The course and several interactive quizzes are available on CD – from the Goodfellow Unit. You may download the order form for the CD-ROM (PDF file).

Author: Hon A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand, 2008.  

Images have been sourced from the following:

  • Hon Assoc Prof Amanda Oakley
  • The Department of Dermatology, Waikato Hospital
  • MoleMap New Zealand (with permission)

 goodfellow unit logo

Introduction to skin surgery

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Learning objectives


  • Techniques used to minimise scarring
  • The use of topical and infiltrated local anaesthetics
  • Methods used for wound haemostasis


Many general practitioners perform minor surgery for benign and small malignant skin lesions. We strongly recommend that you attend regular hands-on workshops in skin surgery to develop and maintain surgical skills. This course does not replace the need for practical training and experience.

To ensure safe practice, aim to comply with published office surgery standards, especially those of Standards New Zealand – ‘The Essential Standards for Health and Disability Services’, include:

  • NZS 8165:2005 Rooms/Office-based Surgery and Procedures
  • AS/NZS 4187:2003 Cleaning, Disinfecting and Sterilizing Reusable Medical and Surgical Instruments and Equipment, and Maintenance of Associated Environments in Health Care Facilities
  • AS/NZS 4815:2001 Office-based Health Care Facilities not involved in Complex Patient Procedures and Processes - Cleaning, Disinfecting and Sterilizing
  • Reusable Medical and Surgical Instruments and Equipment, and Maintenance of the Associated Environment (under revision)
  • NZS 4304:2002 Management of Healthcare Waste
  • NZS 8164:2005 Day-stay Surgery and Procedures (for day surgery facilities)

Indications for surgery

Skin surgery is indicated for the removal of skin lesions that are, or may be, malignant, or if benign, are causing concern because of symptoms or cosmetic appearance.

Patients with large lesions or lesions on the face may be referred to a dermatologist or plastic surgeon for management.

The surgical management of benign and malignant skin lesions may include:

  • Incisional biopsy including punch biopsy, shave biopsy
  • Excision biopsy with primary closure
  • Shave excision
  • Curettage
  • Electrosurgery including diathermy, coagulation and cautery
  • Mohs micrographically controlled surgery
  • Complex reconstruction using flap procedure or skin graft

Combinations of these techniques are often used.

The choice of procedure depends on:

  • Diagnostic or therapeutic purpose
  • Benign of malignant lesion
  • Superficial or infiltrating tumour
  • Size and site of the lesion
  • Patient choice
  • Expertise of the surgeon


The aim is for minimal scarring after any surgical procedure. To achieve this, the excision should occur at right angles to the direction of the resultant pull of the muscles or parallel to natural skin creases and wrinkles – the more creases and wrinkles the less obvious the scar.

Scars are initially red and firm. In time (usually 3 to 12 months), the induration and erythema lessen leaving a soft scar, paler than surrounding skin. Scars tend to stretch, especially when there is loss of skin and obvious wound tension. More conspicuous scarring arises in the following circumstances:

  • Excisions performed during childhood
  • Tendency to form hypertrophic scars and keloids (e.g. dark skinned individuals)
  • If the direction of the scar is perpendicular to the natural lines
  • Certain body sites particularly the upper sternum
  • Haematoma formation
  • Wound infection
  • Wound dehiscence

Suture marks are more prominent in coarse oily skin, for example on the nose, and less obvious in hairless skin such as the margin of the lips, and are less likely with early removal of sutures.

Local anaesthesia

Topical anaesthesia

Topical anaesthesia may be useful for:

  • Scissor snipping of skin tags
  • Incision and drainage of furuncle
  • Diathermy or cautery to telangiectases, comedones and warts
  • Superficial laser treatment

This may be delivered as freezing spray at the time of the procedure (ethyl chloride, nitrous oxide or very light liquid nitrogen), or as a cream applied an hour or two earlier – such as eutectic mixture of prilocaine and lidocaine (EMLA 5% Cream or patch) or amethocaine hydrochloride (Ametop™ Gel).

Intradermal anaesthesia

Most skin procedures require intradermal anaesthetic. Lignocaine (Xylocaine™), an amide, is most commonly used. The onset of action is rapid (one to two minutes) and it lasts one to three hours. The addition of adrenaline 1:100,000 prolongs its duration, reduces toxicity and controls bleeding. The adrenaline should not be used for circumferential block of a digit or penis, or in those with impaired peripheral circulation or serious heart disease.

The maximum safe volume of 1% plain lignocaine in an adult on a single occasion is about 20ml; detailed safety information can be found on manufacturers' data sheets on the Medsafe website. It may be injected using 1 to 5 ml syringe and 23 to 30 gauge needle, or using dental syringe, 30 gauge disposable dental needle and 2.2 ml cartridge.


Methods of haemostasis include:

  • Localised pressure
  • Saline-soaked gauze
  • Mosquito forceps to clamp a vessel inducing spasm
  • Haemostatic solution: Monsel's (20% ferric subsulphate) or 20-40% aluminium chloride in isopropyl alcohol (e.g. Hidrosol™ solution) applied on a cotton tip applicator
  • Silver nitrate stick application (chemical cautery)
  • Pinpoint diathermy
  • Ligature of arteriole using absorbable suture material
  • Oxidised cellulose mesh applied to oozing open wound


Electrosurgery is used for haemostasis and desiccation of tissue using high frequency (0.1-1 MHz), high voltage, and low-amperage currents in a modulated manner. It should in general be avoided in those with pacemakers although modern units are probably quite safe in stable patients providing the path of the electric current does not pass through the heart.

For sterility, disposable tips or needles are used with the hand piece inserted in a sterile glove or specific polythene casing. Reusable tips should be sterilised in an autoclave.

Methods include:

  • Electrofulguration: electric arc from tip of electrode to treatment site
  • Electrodesiccation: contact of electrode with skin (causes deeper tissue injury)
  • Electrocoagulation: damped wave with dispersive electrode or bipolar forceps
  • Electrosection: undamped wave cuts without haemostasis or adjacent tissue injury

Electrocautery uses red-hot wire to burn the tissue. Hand-held disposable and mains-powered heavy duty units are available.

Skin lesion Electrosurgical method
Skin tags, warts, syringomas Gentle electrodessication prior to curettage
Telangiectasia Fine needle electrode and very low power electrodesiccation
Small non-melanoma skin cancers (dermatologists) Shave, curette the lesion prior to electrofulguration / desiccation or cautery (always send specimen for histology)


  • Is there any evidence to support or refute discontinuing low-dose aspirin a week or so prior to skin surgery?
  • In a patient on warfarin, what level of INR would prompt delaying skin surgery?
  • In a patient with thrombocytopenia, what platelet count would make you hesitant to perform elective surgery without platelet transfusion?

Related information

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