Challenges in laser hair removal: A focus on darker-skinned patients
In the past century, unwanted hair has been treated with many modalities that were slow, tedious, painful, or impractical. In any case, the results of the treatment did not last very long. Consequently, there has been a demand for new hair-removal techniques that are fast, reliable, safe, and affordable.
In the last 2 decades, several laser and other light-based technologies have been developed for hair removal. They target hair follicles specifically and treat large areas with long-lasting results. Current goals for improvement in this evolving field are truly permanent photoepilation and the ability to treat white hair and darker-skinned patients. In this article, I will discuss laser hair removal in general, with a focus on treating darker-skinned patients (Fitzpatrick skin types IV–VI1).
Laser hair removal works by sending a beam of laser light toward a group of hair follicles. The light energy causes thermal injury to the follicles. This occurs because laser light is absorbed by water and the hair pigment melanin, and the light energy is converted to heat.2 This process is called selective photothermolysis because it targets only the hair, and not the skin.
The Hair-Growth Cycle
Hair grows in cycles: The active growth phase is termed anagen; the transition phase, catagen; and the resting phase, telogen. The laser is effective only in the anagen phase, during which time the hair contains an abundance of melanin and the hair follicles are easily targeted. When the temperature in a hair follicle becomes high enough during the anagen phase, the treated hair structures are disabled, and hair regrowth is inhibited.
The laser beam “finds” hair follicles by targeting the melanin pigment that gives dark coloration to skin and hair. Therefore, the ideal candidate for laser hair removal has dark hair and light skin. These patients have more significant photoepilation results in fewer treatments than patients with red, white, gray, or truly blond hair.
The laser light is also absorbed by melanin in the skin, so most types of lasers put individuals with suntans or dark skin types at increased risk for pigment discoloration and other side effects. Thus, this category of patients presents a treatment challenge.
However, new laser technologies, especially yttrium–aluminum garnet (YAG) lasers, have made it possible for people with many skin- and hair-color combinations to enjoy the benefits of laser hair removal.3,4 These newer lasers have been designed to safely treat patients of all skin types.
Several laser and laser-like devices are currently used for hair removal. They include, but are not limited to:
the ruby laser;
the alexandrite laser;
light-based or intense pulsed light (IPL), devices;
the diode laser; and
the long-pulse neodymium-doped YAG (Nd:YAG) laser.
|Choosing a Laser|
|Hair Color, Texture||Fitzpatrick Skin Type||Optimum Treatments|
|Light, thin||I–II||Radiofrequency devices |
694-nm ruby laser
755-nm alexandrite laser
|Brown, medium thickness||II–IV||755-nm alexandrite laser 515–1200-nm IPL devices|
|Black, coarse||IV–VI||800-nm diode laser |
1064-nm Nd:YAG laser
These laser devices are all effective, fast, comfortable, and safe for permanent hair removal. Each one has a specific set of advantages and disadvantages, depending on the particular candidate’s skin and hair color.5 A good practitioner can achieve excellent results in patients with a wide range of skin and hair and color types.
A general paradigm to follow for selecting the best laser for your patients is shown in the table below.
There are also several factors that a laser technician can control to customize treatments for efficacy, safety, and comfort:
pulse length—long-pulse lasers are considered to be the safest;
fluence—the selection of energy levels can be varied for skin type;
delay—the time between light pulses affects how much the skin and hair cool off between pulses;
spot size—the larger the area that is radiated, the deeper the laser penetrates the skin. The proper spot-size selection helps the technician reach the hair where it grows; and
cooling—the surrounding skin may be protected by a gel, a spray, or the application of a cooled tip.
Patients who are not ideal candidates for laser hair removal have red, white, gray, or very light blond hair; use or have recently used isotretinoin or sulfamethoxazole–trimethoprim; take photosensitive medications; are suntanned; have very dark skin (except when an Nd:YAG laser is used); or are pregnant. Anabolic steroids should certainly not be taken unless they are medically necessary, because in some cases they can increase male-pattern hair growth.
Medicines that inhibit hair growth (such as spironolactone, cyproterone acetate–ethinylestradiol birth control pills, flutamide, and eflornithine HCl cream) might slightly reduce amount of the pigment in hair roots and make laser treatments less efficient, but this seldom interferes with their overall effectiveness. It is important to remember that even if a patient is not an “ideal candidate,” he or she may still enjoy some benefits of laser hair removal.
Good-bye, Razor; Hello, Laser!
Early in the development of laser hair removal, patients with Fitzpatrick skin types V and VI were not candidates for the procedure, and even patients with skin types III and IV were considered high-risk. However, innovations in laser technology have permitted more effective hair removal in a broader spectrum of patients, including those with the more challenging Fitzpatrick skin types IV–VI or suntanned skin. Long-pulse Nd:YAG lasers effectively treat the darker skin of patients of African-American, Asian, Hispanic, Mediterranean, and Middle Eastern origin.
The Food and Drug Administration (FDA) approved one Nd: YAG laser in 2003 for treating all skin types.6 This laser was designed for deep penetration and minimal scattering of laser energy, and it can be used on very dark skin. If a traditional laser hair-removal device is used on darker skin types, it can result in serious burning or the loss of skin pigment (hypopigmentation). However, with a long-pulse Nd: YAG laser, these patients can be treated with little risk of injury.
To treat patients with Fitzpatrick skin type VI safely with an Nd:YAG laser, they must have a differentiation between their hair and skin colors. Their hair color must be darker than their skin color for effective photoepilation. In addition, caution should be exercised when treating Asian patients, because excessive precooling of the skin may cause hyperpigmentation. Because hair that is naturally blonde, light red, gray, or white has very little pigment in its roots, it cannot be reliably treated with any type of laser at this time.
What Are the Advantages?
Laser hair removal is a noninvasive photoepilation method that does not require needles or messy chemical creams. Because thousands of hairs can be “zapped” in a single treatment session, large areas such as the back, shoulders, arms, and legs can be effectively and efficiently treated.
One of the greatest advantages of laser hair removal is treatment’s speed in combination with long-lasting results. For example, treating the back takes only about 1 hour, whereas treating a full back by electrolysis usually takes 125 hours. Another advantage is that if hair does grow back, it is typically finer and lighter than the removed hair.
What Are the Limitations?
Although an ever-increasing number of published studies of photoepilation have confirmed the safety and short- and long-term efficacy of laser hair removal, the technology still has limits and risks. The goal of the therapy is permanent hair removal, but some patients may experience hair regrowth. In addition, long-lasting laser hair removal typically requires multiple treatments, which can make it costly.
Possible adverse side effects, though uncommon, include damage to the surrounding healthy tissue in the form of scars, burns, redness, pigment changes, and swelling. These complications are generally temporary. Special considerations are important when lasers are used on darker skin tones to allow for safe and effective therapy.
You should engage in a detailed and honest discussion of desired results and expected improvements with each patient. Together, you both can decide if laser treatment is the best option.
Patients should avoid the sun, as well as the use of tanning creams and tanning salons, for 4–6 weeks before and after the treatment. A suntan can interfere with the treatment’s effectiveness and possibly even cause complications. Patients should also wear broad-spectrum (UVA and UVB) sunblock with an SPF rating of 25 or higher before, between, and after treatments. Patients with darker skin tones may start a bleaching cream regimen 4–6 weeks before the treatment to optimize the results.
The area to be treated should be shaved or trimmed the day before or the morning of treatment. Excess hair above the skin surface absorbs and wastes laser energy, and reduces the amount of energy that reaches the hair root, where it is most effective. Excess hair also increases the chance of burning or irritating the skin. Shaving also allows the patient to shape the exact area desired for treatment. This is sometimes very useful in areas such as the hairline, the sideburns, and the bikini line.
Electrolysis and tweezing, plucking, threading, sugaring, and waxing hair must be stopped for at least 2–3 weeks prior to treatment. Hair follicles that do not have hair shafts in them to absorb laser energy will not be treated by the laser energy. If a patient has a history of perioral cold sores or genital herpes in the treatment zone, prophylactic pretreatment with antiviral therapy (acyclovir, valacyclovir, or famciclovir) should be prescribed.
Before laser treatment, the skin should be thoroughly cleaned and dried to remove any makeup, creams, oils, and topical anesthetics. It may be helpful for the patient to take acetaminophen or ibuprofen 2 hours before treatment. Some women find that they are less sensitive after their menses, so they should schedule their treatment sessions accordingly.
Patients have described the sensation of laser hair removal as discomfort rather than pain, similar to the feeling of a rubber band being snapped against the skin combined with an awareness of heat. After the laser hair-removal treatment, patients can expect the treated area to be red and feel similar to a sunburn.
For some patients, a topical anesthetic may be used prior to treatment, although some research has shown that topical anesthetics may decrease the effectiveness of treatment by restricting blood flow to the follicles.
The number of treatments required depends on the patient’s skin color and hair coarseness. At minimum, two to three treatments are required because the process is effective only during the hair-growth cycle. Repeat sessions are necessary to treat follicles as they re-enter the anagen phase. Most laser practitioners report treatments at 4- to 8-week intervals or at the first signs of hair regrowth.
After the treatment, the patient may have redness or bumps in the treatment area. Cold compresses will alleviate this. The skin should be kept moisturized. It is not uncommon for treated skin to be slightly drier after treatment and to require extra moisturizer. The patient should avoid the sun and tanning salons; avoid using tanning creams between treatments; and use a sunblock of SPF 25 or higher.
The only other acceptable hair-removal method during the treatment series is shaving, if needed. Tweezing, plucking, threading, waxing, and sugaring should be avoided, because they can reduce the effectiveness of subsequent laser treatments.
Hair shafts will be released from hair follicles in the treated area for 1–2 weeks after the treatment. Gentle exfoliation or shaving of the areas is permissible. Blistering or scaling after laser hair removal is uncommon, but it usually resolves over a few days by applying bacitracin–polymyxin B or hydrocortisone cream several times per day. Makeup may be used if needed or desired.
How Much to Charge?
Laser hair-removal clinics use pricing structures such as flat fees, cost per pulse, and cost per hour of session. Most of these result in similar total costs, but clinics may favor different pricing structures for reasons such as ease of use, reliability, and ability to customize according to the client’s needs.
Offering guarantees for treatment outcomes can be a risky proposition. Individual patients may respond differently to treatments, so they must be counseled regarding appropriate expectations.
The evolution of new technologies has improved the clinical efficacy of laser hair removal and has increased the understanding of hair biology. With the recent FDA approval of Nd:YAG lasers for tanned skin and darker skin types, long-term hair removal is now a realistic goal for most individuals.
Newer radiofrequency technologies might address the difficult issue of white and light blond hair types; however, their exact role in the laser hair removal armamentarium remains to be determined. Until then, current laser treatments provide gratifying and effective results.
Benjamin A. Bassichis, MD, a double board-certified facial plastic and reconstructive surgeon, is the director of the Advanced Facial Plastic Surgery Center in Dallas. He lectures throughout the country on the latest cosmetic surgery procedures, and he has been featured on prominent national news programs. He is a clinical assistant professor at the University of Texas–Southwestern Medical Center and volunteers to care for patients at the Veteran’s Administration Hospital, Dallas. He can be contacted at (972) 774-1777 or on his Web site, www.advancedfacialplastic.com.
1. Fitzpatrick TB. The validity and practicality of sun-reactive skin types I through VI. Arch Dermatol. 1988;124:869–871.
2. American Society for Dermatologic Surgery. Laser applications. Available at: http://www.asds-net.org/old/Patients/FactSheets/patients-Fact_Sheet-lasers.html Accessed July 5, 2005.
3. Hairlasers.com. Types of laser hair removal systems. Available at http://www.hairlasers.com/laserremoval/systems.html Accessed July 5, 2005.
4. Hairlasers.com. How hair removal by laser works. Available at: http://www.hairlasers.com/laserremoval/information/howitworks.html Accessed July 5, 2005.
5. Hairlasers.com. Will laser hair removal work for me? Available at: http://www.hairlasers.com/laserremoval/candidates/index.html Accessed July 5, 2005.
6. US Food and Drug Administration. 510(k) summary of safety and effectiveness for the Candela GentleVAG family of laser systems. Available at: http://[removed]www.fda.gov/cdrh/pdf3/k033172[/removed].pdf Accessed July 5, 2005.