Laser hair removal popular

September 1, 2007

Several lasers and other light sources are available today for hair epilation. Though physicians have extensive experience with photoepilation devices, there are still several problem areas that both patient and physician must face.

Key Points

Petah Tikva, Israel - As the popularity of photoepilation treatments for hair removal continues to surge, it has become a mainstay in the modern dermatologic practice.

Excessive hair growth can be due to hypertrichosis, hirsutism, cosmetic reasons or pseudofolliculitis caused by ingrown hair. While many physicians have extensive experience with laser treatments, there are still several gray areas, including pregnancy issues, reactive hypertrichosis, permanency of treatment and the development of livedo reticularis. One expert dispels certain myths.

As the demand for cosmetic hair removal grows, so does the need for more rapid, noninvasive treatments. This has led to the development of various light sources for epilation including ruby, alexandrite, diode and Nd:YAG lasers, as well as intense pulsed light (IPL) sources.

Referencing the regrowth of hair following epilation treatment, Dr. Lapidoth tells Dermatology Times that a major factor in regrowth is the anatomical site treated. The face and chest can present a regrowth of hair over some years, but this is much more unlikely in areas such as the legs, inguinal area, axillae and hands.

There is a complete depletion of the androgen receptors in the axilla and pubis, but these receptors remain intact in the face and may have an influence on the vellus hairs later in life, Dr. Lapidoth says.

In general, he says that reactive hair growth or reactive hypertrichosis is an uncommon event, citing several studies which demonstrated that the percentages of hair regrowth or hair induction are very low. Patients particularly at risk are young, ages 14 to 35, Mediterranean skin type (skin type IV to VI) and have a predisposing anatomical location.

Informing patients

Dr. Lapidoth stresses that patients should be well informed about the possibility of hair regrowth.

Patients should understand that multiple treatments are usually the rule, and that partial or complete re-growth of hair, as well as side effects and complications, such as pigmentary changes, infections, skin textural changes, urticaria and vascular phenomena, are all possible.

One such rare vascular phenomenon that may occur following an epilation treatment is livedo reticularis. Dr. Lapidoth says this is a mottled bluish discoloration of the skin with a net-like pattern that may be due to venous drainage at the margins of areas of skin richly supplied by arterial cones.

"When factors such as cold cause increased viscosity and low flow rates in the superficial venous plexus, further de-oxygenation occurs, and the cyanotic reticular pattern becomes more pronounced. Therefore, this pattern may result from arteriolar disease causing obstruction to inflow, from blood hyperviscosity or from obstruction to outflow of blood in the venules," Dr. Lapidoth says.

According to Dr. Lapidoth, the reasons for the development of livedo reticularis are clear. He says during laser treatment, absorption of the laser light in the oxy- and deoxyhemoglobin raises the blood temperature. Permanent thermal damage (i.e., coagulation) will occur if the blood exceeds a threshold temperature for more than a critical period of time. Also, because of the relatively static chromophore Hb and slow blood flow, damage to the arterioles is significant, leading to livedo reticularis.

Patient selection

Dr. Lapidoth says that, in some cases, the physician should be wary to treat or not treat at all.

These include patients taking photosensitive medications, e.g., Accutane (Hoffman-LaRoche), pregnant patients and those with photosensitivity diseases.

Contraindications

"Although laser or IPL hair removal physically has no impact on pregnancy, most laser manufacturers exclude the use of photoepilation in pregnant women in their application notes.

"Photoepilation could be discontinued in the first two trimesters of pregnancy. In the third trimester of pregnancy, photoepilation could be undertaken within the responsibility of the physician, as the fetus is completely formed and there is no risk of fetal malformation known," Dr. Lapidoth says.