Laser Hair Removal Facts,
Laser hair removal with electrolysis and waxing to the pulsed light method of permanent hair removal. It has been done experimentally in the 1970s about 20 years before the first commercial acts.
The methods based on laser light is sometimes called photo-epilation. In parallel the laser, some machines use a xenon lamp (called "flash bulb") which emits a spectrum of bright light (intense pulsed light or IPL). Treatment with the flashlamp are sometimes commonly called "laser hair removal" but does not really.
Principle
The basic principle of laser hair removal is the "selective thermolysis". The laser causes localized damage in hot areas emitting black hair without burning the rest of the skin. The light is absorbed by the black areas called chromophores.
Laser hair removal targets primarily melanin. There are two types of melanin: eumelanin (which gives skin and hair black) and pheomelanin (which gives hair brown, the color of Asian skin and freckles).
Less hair contain melanin, the laser is less effective. For this reason, people with gray hair, brown or blond are not good indications for laser hair removal.
On the other hand, the skin contains more melanin, the lower the laser comes to the difference between skin and hair. For this reason, black people or very dull skin can benefit from treatment with conventional lasers (Alexandrite or type flashlamp (IPL / intense pulsed light)). For dark skin, was developed specific lasers in the infrared between 800 and 1064 nm. Lasers of 810 nm diode often can, by lengthening the time of application of energy, tweezers darker skin. 1064nm infrared lasers or Nd: YAG has a lower affinity for melanin. This lower affinity helps preserve the skin dark, while keeping some effectiveness on the hair (especially the hair on black skin are highly concentrated melanin). These lasers typically require a few more sessions, but can treat dark skin. The manufacturer has, unfortunately, tend to indicate that these lasers can remove hair from hides tanned while sunbathing must reject patients because it is an indication temporary-cons (laser less effective because the target away from hair, increased pain, increased risk of burns).
A light skin and dark hair is the best combination for laser hair removal. For other negatives, special lasers or electrolysis will be offered.
Laser parameters
Several wavelengths of laser energy are used for laser hair removal. Since visible light to near infra-red. These lasers are generally designated by the type of wavelength they produce (measured in nanometers, nm):
* Argon: 488 or 514.5 nm
* Ruby: 694 nm
* Alexandrite: 755 nm
* Pulsed diode array: 810 nm
* Nd: YAG: 1064 nm
* Flash Light: spectrum of about 600 to 1000nm, which varies depending on the aircraft.
The width of the laser beam (spot) is also important. It should normally be 4 times larger than the target is deep. Most lasers have a spot round 8 to 10 mm.
The fluence or energy is an important consideration. It is measured in joules per square centimeter (J / cm ²). Another important parameter: irradiance, reflecting the speed at which it delivers energy (W/cm2).
The rate of repetition has a cumulative effect. Firefox 2 or 3 pulses on the same target with a specific delay between each pulse can improve the heating zone.
The cooling of the skin can increase the influence and reduce pain. We therefore usually use a gel or a fresh air system associated with the laser.
The spacing of laser hair removal sessions depends on the speed of hair regrowth and function of the treated area. The face usually requires, for the first sessions of intervals of 3 to 5 weeks. For regions of the body, there are spacings of 8 to 10 weeks for the first sessions. It's the hair cycle which controls the spacing between sessions. A laser treatment effective leads, meeting after meeting, pushing a bit more slowly, more and finer, more and more clear, more and more rare. There are areas easier to treat than others. The simplest underarms, bikini, 1 / 2 legs where the hairs are quite large and pigmented. The more complex knee, thigh, face, breast, where the hairs are coming over for some colorful and therefore less responsive to laser energy.
Complications and side effects
The main side effect is the risk of burning when the laser is heating the surface area of skin rich in melanin if there is rust. The darker skin, but not tanned, can benefit from laser hair removal with lasers specific type of diode laser pulse lengthened or Nd: YAG. These lasers have less affinity with melanin and can affect the concentration of melanin in hair, not too touch the melanin in the skin. The cons-tan is formally indicated if the skin is tanned. It should protect themselves from sun exposure between 15 d and 3 weeks after laser hair removal (use of sunscreen type sunblock, index 50 or more). Most laser burns are like first or second degree level light. They usually operate well but the return to normal can take several months. It should remind patients that, in some rare cases, the burn can leave a permanent depigmentation. The burns on dark skin or the simple passage of the laser without burning a real dark skin can cause a phenomenon of inflammation with the development of hyperpigmentation can be extremely slow to disappear. Hair removal lasers skins Mediterranean, so it is very effective, should be no exception in care towards tanning. The Laser hair removal should not pass over areas of tattooing in order not to cause burns deep accumulation of energy in the pigment of the tattoo. The tattoos are generally altered laserises cause complications and scarring. Finally, laser hair removal should not be used on skin with inclusions of explosive material (powder gun for example). It is important that the physician do a search for healing disorders or bleeding disorders before initiating a session of laser hair removal so as not to cause bruises or scars. certain medications (anti-epileptics, antibiotics ....) can increase the sensitivity of laser skin and cause burns to doses usually trivial. Must report any medication taken in laser physician. Some acne medications like Accutane (r) may increase the risk of abnormal scarring (keloid or hypertrophic scars). We must stop over 6 months before starting laser hair removal. In principle, we n'epile not pregnant or lactating women. No birth or abortion has never been described, but should apply a precautionary principle. Many authors indicate no risk during pregnancy. A burn during pregnancy may however complicate management and may eventually develop poorly. It is not prudent to expose patients to risk, it was very rare.
Read also Radiation therapy
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