Page 249 - Chapter 3 - Laser/IPL Hair Removal

Chapter 3 – Fundamentals of Laser/IPL Hair Removal 2nd Edition
session). They found that in some studies the participants reported virtually no unwanted side- effects from self-treatments with HUDs, while another study indicated erythema, oedema, crusting, hyper- and hypopigmentation. However, all of these side-effects resolved by the three month follow-up check. It should be noted that erythema immediately post-treatment is a typical clinical endpoint with high-fluence devices in clinics, and usually indicates a favourable response.
Conclusions
We noted two very interesting comments from these reports:
“In-vivo studies demonstrated that low fluence home-use devices can result in high hair reduction efficacy after a short treatment regime, while prolonged and less frequent (once in six weeks) maintenance treatment over a year can lead to high and sustained hair reduction even one year after cessation of treatment.” (Town et.al.).
These researchers also suggest that “Home-use devices can be a useful adjunct to professional in-office treatments with high professional awareness.”
It appears that fluences below 10 J/cm2 will induce a ‘catagen-like’ transition leading to temporary hair reduction. But it seems that these HFs do not go back into a ‘normal’ hair growth cycle immediately. Repeated treatment sessions appear to extend this ‘hair-free’ time.
It may be that low fluence (< 10 J/cm2) treatment of hair, with IPLs or lasers, will be a temporary hair reduction technique, lasting as long as the user continues with repeated sessions.
An interesting physiological point - the melanised hair shaft is not typically visible above the skin surface until anagen 5. This appears to occur when the DP has become embedded in the sub- cutis layer, which may be a number of weeks after the initiation of the anagen (depending on the thickness of the dermis). Consequently, if the real target is the melanised DP/HG, then there is no associated hair visible when these targets are very superficial, and, therefore, easily targeted with light. There may be a club hair from the previous telogen phase which is visible, but it is not yet possible to determine which of these hair follicles is undergoing early anagen.
Finally, we have yet to find a clinical report which categorically states that repeated treatment sessions with low fluences results in a permanent hair reduction result. All reports studied to date, imply that this might be the case; but, as yet, this has not been proven.
________________________________________________________________________ 249 Chapter 3, Ed. 2.0 Laser/IPL Hair Removal
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