The Procedure

Sweat is produced from the eccrine glands in the skin. Laser sweat ablation is aimed at destroying the eccrine glands and then removing them, whilst causing as little damage to the skin as possible.

Therefore, to understand the technique, it is important to understand where the eccrine glands are in the skin.

From the outside, the top layer of the skin is the keratin (or ‘horny’) layer. This is a layer of dead skin cells (dead epithelial cells) that lie on the surface and help to protect the skin.

The next layer down is the epithelium. This is the upper layer of living cells. It is formed by several layers of cells, formed from basal cells at the bottom of the epithelial layer, which then get pushed up through the layers, until they die and become part of the keratin layer.

Under the epithelial layer lies the dermis. The dermis is the really important layer of the skin. It provides all the nutrients for the epithelial layer, as well as holding the accessory structures of the skin – such as hair follicles, eccrine sweat glands, sebaceous glands etc. Of note for laser sweat ablation, the eccrine glands lie deep in the dermis, close to the bottom of the dermal layer.

Under the dermis is the sub-cutaneous fat.

The principles of laser sweat ablation are as follows:

  • The area of maximum sweating is marked on the skin by performing an iodine and starch test
  • Local anaesthetic is used to completely numb the area
  • 2 small incisions – typically about 5mm long, are made and the dermis is separated from the subcutaneous fat
  • The laser fibre is put into this area and the laser is fired at the underside of the dermis, destroying the eccrine glands. As these glands lie deep in the dermis, they are easily reached by approaching them from below.
  • The dead glands are removed by suction curretage – literally scraping the underside of the dermis and sucking out the tissue that is scraped off the underside of the dermis.
  • Long acting local anaesthetic is placed along with compression dressings to push the skin back into place on the sub-cutaneous fat. A compression waistcoat holds this in place for 2 – 3 days after the operation.

Obviously this is only an outline of the procedure and there are several extra technical details that we do to improve the results – but this gives the general principles of the laser sweat ablation (LSA) procedure.