Dermatology Instruments

Curette or punch? It decides whether you get a diagnosis

This is the choice that matters most on this page, and it is not about size.

A dermal curette scrapes the lesion off at the level of the dermis. It is quick, bleeds little, heals with good cosmesis, and needs no closure. But it fragments the tissue. A pathologist receiving curettings can often identify the cell type and can almost never read the margin or the depth of invasion.

A dermal punch takes a full-thickness cylinder with the architecture intact - epidermis, dermis, and the junction between them in their real relationship. That is what makes depth and margin readable. The cost is a wound that usually needs a suture.

So: if the lesion is being removed, a curette is often the better instrument. If it might need diagnosing - anything pigmented, anything ulcerated, anything that has changed - the punch is the instrument, and reaching for the curette first can cost the specimen that would have answered the question.

Sizing a Fox curette

The number on a Fox curette is the cup diameter, not the handle or the shaft: 1mm, 2mm, 3mm, 4mm, 5mm and 6mm are all stocked here.

The rule is the smallest cup that still seats over the lesion. An oversized cup does not scrape more efficiently - it catches surrounding normal skin at the rim, and instead of lifting the lesion cleanly it tears across the boundary. That is the commonest reason a curettage leaves a worse scar than it should have.

Piffard curettes cover the same ground with a heavier handle and three sizes (3mm, 5mm, 6mm), which suits a firmer scrape on thicker skin.

Why a nail splitter has an anvil

Cutting a nail plate with ordinary scissors presses the plate down into the nail bed as the blades close. On an already inflamed or infected toe that is the painful part of the procedure, and it is avoidable.

A nail splitter puts one thin blade underneath the plate and a flat anvil above it. The anvil absorbs the closing force instead of the nail bed, so the plate is divided in place rather than levered. The 2mm Fig. 59 pattern suits a partial nail avulsion; the 13cm anvil pattern is for a full split.

Comedone extractors

Saalfeld, Schamberg, Unna and Walton patterns, in 10cm and 14cm, single- and double-ended. The differences are the loop size and whether the instrument carries an acne lancet at one end - a lanced lesion extracts with far less pressure, which is what protects against the bruising and secondary scarring that heavy-handed extraction causes.

Frequently asked

Are these reusable? Yes - reusable, autoclavable instruments throughout. Disposable punches are a separate category.

What is the difference between a Keyes punch and a Fox curette? The Keyes is a punch: a cylindrical cutting edge that cores. The Fox is a curette: a sharpened cup that scrapes. They are not alternatives for the same job - see the first section.

Do the Freeman retractors belong in dermatology? They are flap and rake retractors used in plastic and reconstructive work on skin, which is why they sit here rather than with the abdominal retractors.

Related collections

See also Surgical Curettes, Surgical Knives & Knife Handles, Surgical Scissors and General Surgery Instruments.