Page 32 - Chapter 3 - Fundamentals of Laser/IPL Hair Removal

Chapter 3 – Fundamentals of Laser/IPL Hair Removal 1st Edition
Skin Colour 6 – ‘Black’ skin
It is important to note that when treating black skin it is not easy to detect erythema (reddening of the skin). Therefore, particular care must be taken when observing the reaction of black skin to light therapy.
In black skin the stratum corneum is thicker than in paler skin. Pigmentary granules are usually present in desquamating cells of black skin, but not of white skin. Black skin is also more prone to the formation of keloid scars. A keloid is an excessive formation of scar tissue at the site of an injury to the skin. Keloids can continue to grow and harden for several months after the initial injury.
It is particularly important to ensure that any client with black skin undergoes the test patch procedure and that they are carefully informed of the potential side-effects resulting from this type of treatment.
Note that dark skinned clients will feel more sensation with laser/IPL treatment simply because of the higher absorption of light energy compared with lighter skin colours. Therefore, they typically require more skin surface cooling than normal. However, it may simply not be possible to cool black skin sufficiently for this treatment, due to the high melanin concentration!
Skin colour = epidermal melanin content
The darker the colour, the higher the temperature in the epidermis during laser/IPL treatments – more potential damage
Epidermal temperature rise due to skin colour
The fluence must be chosen to kill the germ cells in the target follicles. Those are the real targets – not the melanin in the hair shaft. That melanin can be viewed as a surrogate which we can heat using light energy. But, the germ cells do not have a chromophore which we can exploit using light.
So, to kill the follicles we must heat the hair shaft melanin sufficiently to denature the germ cells irreversibly. The skin colour is completely irrelevant in this consideration! It doesn’t matter what the skin colour is – only the hair colour. The skin colour (in the basal layer of the epidermis is simply a barrier we must surmount).
________________________________________________________________________ 32 Chapter 3 Laser/IPL Hair Removal
© The Laser-IPL Guys, 2022