Aesthetician
and Skin Care Services
Hair Removal
Unwanted
body hair is a problem for both women and men. Traditionally hair
may be removed by shaving, plucking, waxing and electrolysis.
In the early 1990’s, the reports of using laser energy to
selectively damage and disable actively growing hair follicles
were published, and since the mid-1990s, laser hair removal has
become the "gold standard" method for hair removal.
There are several laser hair removal systems available today;
they all work using the principle of selective photothermolysis,
in which a carefully timed pulse of laser energy passes through
the skin and is absorbed and converted to heat energy at the hair
follicle. Because longer wavelength laser light penetrates deepest,
the most common lasers used are the Ruby, Alexandrite, Diode,
and indeed: ND:YAG lasers, all red or infrared
lasers.
Laser hair removal works best in lighter skin, darker haired
patients. Because the target chromophore (pigment that absorbs
the laser light) in the hair follicles is a melanin pigment,
and there is a greater concentration of melanin in the hair, the
skin absorbs less laser energy and more is absorbed by the hair
follicle. Tanned skin and darker skin types may rob laser energy
as it passes through the skin to the hair follicle. The infrared
ND:YAG lasers is less dependent on skin color
than the Ruby or Alexandrite lasers. In fact, this type of laser
has been used to treat pseudofolliculitis barbae, observed in
men, frequently African-American, secondary to shaving, with no
complication of pigmentation changes of the neck or facial skin.
This is the only laser that is approved for darker pigmented patients.
Multiple treatments are necessary for best results. This is because
the laser energy has its greatest effect on growing, or anagen
hair follicles; as the dormant, or telogen hairs become active,
usually within three weeks to three months, some new hair growth
will be observed. The female face, armpits, and bikini lines are
the areas that respond fastest to laser treatments; backs, arms
and legs are usually need more treatments over time. Repeated
laser treatments appear to induce a permanent reduction in the
amount of visible hair. Some hair growth, however, may occur over
time; if this occurs, the hairs are usually finer and grow much
slower than before treatment. Total hair removal may be possible
with repeated treatments over time.
As noted, there are alternative laser systems available for hair
reduction. All laser systems attack the melanin pigment that is
produced in the bulb, and possibly the bulge, of the hair follicle.
Actively growing hairs are the longest and deepest. The melanin
pigment (the target for laser hair removal) is most abundant
in the hair bulb and less abundant in the skin.
The reason for the center using the ND:YAG lasers
over other lasers on the market is that as the wavelength of laser
light increases from 630-nm to 1100-nm, epidermal (skin)
melanin absorbs progressively less radiant energy. This means
that the epidermal layer containing cutaneous melanin is not going
to heat up as much when it sees ND:YAG lasers
energy as opposed to that of shorter wavelengths such as a 755-nm
Alexandrite or 810-nm diode laser. Then, as the amount of melanin
in the epidermal layer increases, these shorter wavelengths have
to expend more and more energy to penetrate the epidermis; this
applies more heat to the skin and less to the hair follicle. This
means a greater chance of pigmentation changes of the skin or
blistering. The longer wavelength ND:YAG laser's
photons "slide through", giving a greater probability
of destroying the hair follicle with associated less expenditure
of energy. Properly designed, the laser energy will target the
melanin and hair follicles, while sparing adjacent structures,
including melanin in the epidermis. The optimum pulse duration
should be longer than the thermal relaxation time of the epidermis,
allowing heat energy to be conducted away, but shorter than the
thermal relaxation time of the hair follicle, confining the heat
to the structure. This process is facilitated by cooling the skin,
leaving the deeper hair follicles more vulnerable and by having
longer pulses that enhance the heating and expand the zone of
thermal damage to the hair follicle.
Treatments are scheduled at 6 week intervals. A cooling system
is utilized to minimize the discomfort. The patient is advised
not to tan for 1 month before or after the treatment. There is
little reaction to the treatment and one should be able to return
immediately to normal activity.
Complications - The potential complications
of laser hair removal are blistering, change in skin pigmentation,
and limitation of result.
