Page 122 - Chapter 3 - An Introduction to Laser/IPL Hair Removal

Chapter 3 – Fundamentals of Laser/IPL Hair Removal 1st Edition
Skin surface
Figure 59 – A model of the skin in cross-section. When applying a 5oC cooling tip to the skin surface, the depth of cooling varies with the applied cooling time.
What is the risk of burning the skin with a laser or IPL?
Many people are worried about ‘burning’ the skin during laser/IPL treatment of hair, tattoos, blood vessels etc. But, what is the actual risk?
Well, we can work this out knowing the skin colour and the applied fluence. As discussed previously, the Fitzpatrick Scale does not determine skin colour (contrary to popular belief!!). In fact, the Fitzpatrick Scale simply looks at the skin’s response to ultraviolet light energy and what that exposure may do. But we can use another method to precisely determine the colour. Using data from an American scientist, Steve Jacques, we can determine the ‘colour’ of the skin by specifying the concentration of melanin in the epidermis (see Figure 4).
We use the same numbering system as the Fitzpatrick Scale since this is very familiar to many people. But, as we can see, if you go on holiday and come back with a tan, your melanin concentration will increase – changing your ‘skin colour’. However, your Fitzpatrick number does NOT change!!
Table 32 – Skin colour versus melanin concentration
________________________________________________________________________ 122 Chapter 3 Laser/IPL Hair Removal
© The Laser-IPL Guys, 2022
Skin colour Melanin concentration
1 Up to 10%
2 10-16%
3 16-23%
4 23-33%
5 33-43%
6 >43%