Dermatologic Surgery and Procedural Dermatology
Before the knife
Confirm the diagnosis, take consent including scarring and recurrence risk, check anticoagulants and allergies, mark the site with the patient awake, and plan margins in advance. Ellipses should be roughly three times as long as they are wide, with 30-degree tips, oriented along lines of minimal tension.
Anaesthesia and haemostasis
Buffered lidocaine 1% reduces injection pain. Maximum safe doses: lidocaine 3 mg/kg plain and 7 mg/kg with adrenaline; use lower figures in small children and cardiac disease. Adrenaline at appropriate concentrations is safe in digits and ears. Always calculate the dose against body weight before anaesthetising a large area.
Procedures
Shave plus curettage for seborrhoeic keratoses and superficial BCCs; formal excision for melanoma and diagnostic uncertainty; Mohs for high-risk, recurrent or cosmetically critical tumours with margin mapping; cryotherapy for warts and selected actinic keratoses; electrosurgery for small vascular lesions.
Aftercare and complications
Haematoma, infection, dehiscence, hypertrophic scar and keloid (higher risk in darker skin and on chest and shoulders), pigmentary change, and nerve injury. Typical suture removal: face 5–7 days, trunk 10–14 days, limbs 14 days.
Traps
- Wrong-site surgery - mark standing up with the notes open.
- Exceeding the lidocaine maximum by ignoring body weight.
- Shave biopsy of a possible melanoma.
- Cancelling surgery unnecessarily for anticoagulation; most cutaneous surgery proceeds with careful haemostasis and an INR within range.
Rule of thumb
If the diagnosis is uncertain, take the whole lesion with a narrow margin rather than sampling part of it.