Shorter Pulsed Laser Found Safe for Hair Removal

A new study reports that a laser that delivers energy pulses shorter than those currently considered standard practice is effective and safe for hair removal. The study appears in a recent issue of the Journal of Cosmetic and Laser Therapy.

Laser pulse duration is believed to be an important factor in the safety and efficacy of laser treatments. Studies have generally found that although longer pulses are safer for darker skin, shorter pulses tend to be better at removing hair. Fluence, or energy level, is also important. Generally, the higher a laser’s fluency, which is measured in joules per square centimeter (J/cm2), the longer-lasting the treatment

This new study was designed to evaluate the efficacy of a shorter pulsed, 0.65 ms Nd:YAG laser. Six women were recruited. Using a Nd:YAG laser with a wavelength of 1064 nm and a pulse duration of 0.65 milliseconds, each woman had one-half of each underarm treated. The other half of the underarm was left untreated as a control. The laser fluence used on the treated areas was either 21 J/cm2 or 36 J/cm2. The women received 4 monthly treatment sessions. A manual hair count was conducted before each session and at a 4-month follow-up visit.

The results: At the four-month follow-up, there was a 75% to 100% reduction in hair on the high-fluence treated areas and a 50% to 75% reduction on the low- fluence areas. The average hair count declined 76% on the high-fluence areas and 72% on the low-fluence areas.

“This well-controlled study shows that a 0.65 ms ND:YAG laser is effective and safe for hair removal,” the authors concluded.

Source: Khatri KA, Lee RA, Goldberg LJ, Khatri B, Garcia V. Efficacy and safety of a 0.65 millisecond pulsed portable Nd:YAG laser for hair removal. J Cosmet Laser Ther. 2009. Feb 6:1-6. [Epub ahead of print]

Laser Hair Removal Treatments Well-Tolerated in Children, Study Shows

Using lasers to remove unwanted hair in adults is known to be safe and well tolerated, but what is the safety and tolerability of the procedure in children? Children also have conditions, including hypertrichosis and hirutism, that result in excessive hair, which can lead to significant psychosocial distress. Families often resort to extreme measures to minimize the undesired appearance of unwanted hair, including neonatal shaving, trimming, plucking, bleaching and waxing. Increasingly, parents have turned to laser hair removal treatments for their children, despite the lack of extensive investigations into its safety and efficacy for this age group.

In an article in the journal Clinical and Experimental Dermatology, British researchers describe their experience with laser hair removal in 24 children under the age of 16 years. Depending on their skin type, the children received a minimum of three treatments with a long-pulse alexandrite laser (with either continuous chilled-air cooling or cryogen cooling) or a long-pulse Nd:YAG laser (with either a chilled contact sapphire tip or cryogen cooling).

The mean age of the children was 12.3 years. They were diagnosed with constitutional hirsutism (14 patients), polycystic ovarian syndrome (5), congential melanocytic naevus (2), generalized hypertrichosis (2) and naevoid hypertrichosis (1). Before the treatment, 1 patient required a general anesthetic, 8 required a topical anesthetic, and 15 needed no anesthetic at all.

The results: Only two children experienced discomfort that required adjusting the fluence of the laser. This was the only side effect. No incidences of blistering, infection, dyspigmentaion or scarring occurred.

The authors concluded that “[w]hen administered appropriately, laser hair removal is safe and well tolerated in children aged < 16 years.”

Source: Rajpar SF, Hague JS, Abdullah A, Lanigan SW. Hair removal with the long-pulse alexandrite and long-pulse Nd:YAG lasers is safe and well tolerated in children. Clin Exp Dermatol. 2009. Jan 23. [Epub ahead of print]