Laser Hair Removal

The Connection between Laser Hair Removal and Fitzpatrick Skin Type

Laser Hair Removal

Laser Hair Removal Statistics for 2012 from the American Society for Aesthetic Plastic Surgery show that over one million laser hair removal treatments were performed in the United States during the calendar year, making this the third most popular cosmetic procedure overall. Yet, despite its growing prevalence, not everyone is a candidate for permanent hair reduction using laser technology – darker skin tones often require a different approach. For a better gauge of which settings to use when performing the treatment for people with darker skin tones, laser technicians refer to the Fitzpatrick Scale.

The Essentials of Wavelength

Through selective photothermolysis, different light wavelengths are used to target the laser-absorbing chromophore in the hair follicle. As the darker pigmentation absorbs the light, it converts to heat that generates throughout the hair shaft. This causes mechanical hair follicle damage as a result of protein coagulation, disrupting the hair growth cycle through a controlled process.

The wavelengths must be specifically selected to penetrate the skin enough to reach the chromophore. With the high sensitivity levels of the lasers used during hair removal, the brown melanin is easily targeted. The melanin-producing melanocyte cells comprise about eight percent of the epidermis. As such, correctly setting the proper wavelength and depth of penetration to account for natural melanin levels in the skin is essential to avoid damaging the treatment area; otherwise, cutaneous pigment can too easily absorb the heat energy before it reaches the hair follicle.

A Systematic Approach

The Fitzpatrick skin type scale helps determine who are the best candidates for laser hair removal. This guide, developed by Harvard dermatologist T.B. Fitzpatrick in 1975, remains the recognized standard for classifying different skin tones according to UV response. When applied to laser hair removal, laser technicians are better able to determine an appropriate treatment strategy for each patient.

The Fitzpatrick Scale offers six classifications for skin response to UV exposure:

  • Skin Type 1: Very pale or freckled. Always burns; never tans.
  • Skin Type 2: White. Typically burns; sometimes tans.
  • Skin Type 3: White to Olive. Sometimes burns; always tans.
  • Skin Type 4: Brown. Rarely burns.
  • Skin Type 5: Dark Brown. Very rarely burns; moderately pigmented.
  • Skin Type 6: Black. Highly pigmented.

The highest risk of injury is to those of skin types four, five or six. These classifications typically include those of African-American, Asian, East Indian, Latino or Mediterranean heritage. Hypopigmentation, hyperpigmentation, surface burns and even permanent scarring are all potential risks that can occur if the wrong setting is used. Spot tests using varying levels of intensity are essential before committing to a full treatment. The delayed reaction typical of darker skin tones necessitates a wait of 48-72 hours following the spot test.

Myths vs. Reality

Despite the widespread myth that laser hair removal on darker skin tones is impossible, this simply isn’t true. The technological advances of laser treatments offer today’s technicians the ability to achieve safe and effective laser hair removal on a variety of different skin tones. However, darker skin tones do require longer wavelengths and pulse widths like those found in the Nd:YAG laser. Lasers like the 810nm Diode can also be effective for mid-range skin tones despite their shorter wavelength, as long as specific, expanded pulses are integrated with the proper cooling attachments. Caution is recommended; melanin so effectively absorbs even these wavelengths that epidermal damage does remain a risk.

The most optimal laser for the darkest skin tones is the Nd:YAG 1064nm, which successfully penetrates deeply below the skin to target the hair follicle chromophore while bypassing the epidermal pigment. The longer wavelength combined with customized modifications in laser pulse timing and energy levels offer the safest level of treatment for higher numbers on the Fitzpatrick Scale.

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November 7, 2013
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