12. Laser treatment for unwanted hair Marc R Avram INTRODUCTION Hair is a physical characteristic that helps distinguish each one of us as individuals. The color, length, and texture of hair on our scalp are among the few physical characteristics that we can control. Hair frames our face. A full head of hair makes any individual appear more youthful. Millions of people try to maintain their hair with medication and surgery.1 While a positive physical characteristic on the scalp, eyebrows, and eyelashes, hair on almost every other part of the skin is perceived as a negative physical attribute. For decades, millions of people sought treatment to remove unwanted hair. The majority of treatment options resulted in a safe but temporary reduction of hair requiring regular maintenance throughout life. In the 1990s, the most significant new treatment option to permanently destroy hair was introduced: laser hair removal.2 Laser hair removal is based on the theory of selective photothermolysis.3 Selective photothermolysis has revolutionized the therapeutic role of lasers in medicine. In the skin, prior to removing hair, it was successfully applied to treating unwanted vascular lesions, pigmented lesions, tattoos and wrinkles.4–6 Laser hair removal has become one of the most popular cosmetic procedures over the past ten years or 50. For millions of patients, it has resulted in a long-term reduction in unwanted hair. As with any procedure, appropriate candidate selection and expectations are vital to its success. Appropriate candidate selection, expectations, choice of laser/light device, and the risks of the procedure and how to minimize them are established during a medical consultation. THE CONSULT All patients undergoing laser hair removal should have a medical consultation before the procedure (Table 12.1). For the vast majority of patients, unwanted hair is the result of a combination of benign hormonal and genetic factors. In a minority of patients, unwanted hair can be a cutaneous sign of an underlying medical condition or a side-effect of medication.7 A medical consultation is needed to help distinguish between the two. The target chromophore for laser/light sources using selective photothermolysis is thought to be melanin.8 This is the reason current technology only works on pigmented hair. Patients with blond, gray, or lightly pigmented hair will see no improvement from laser/light sources, and should not undergo treatment. All skin types can undergo successful hair removal. Since melanin is the target chromophore, the risk of cutaneous hyper- or hypopigmentation in darker skin types is higher with shorter wavelengths such a 694 nm ruby, 755 nm alexandrite or 800 nm diode lasers. Longer wavelengths with longer pulse durations such a 1064 nm long-pulse yttrium aluminium garnet (YAG), penetrate deeper into skin relatively Table 12.1 Candidate selection Good candidate Poor candidate Pigmented thick hair Unpigmented hair All skin types Vellous hair Realistic expectations Persistent sunburn Unrealistic expectations Carniol-12.qxd 6/1/2007 7:54 PM Page 134 134 Clinical procedures in laser skin rejuvenation sparing epidermal pigment and reducing (but not eliminating) the risk of hyper/hypopigmentation.9 The caliber of the hair follicle also helps determine the success of the procedure. Thick hair tends to respond better than thin vellous-like hair. In a small minority of patients with a lot of vellous hair, a paradoxical growth of hair may even occur.10 The reason for this remains remains unknown. The laser works best on follicles in an anagen phase of growth. This results in the need for multiple treatments to achieve a clear clinical hair reduction. Since follicles in the anagen phase are the target, treatments should be spaced between 4 and 12 weeks depending on the location on the body.There is variability on how well each patient will respond. Most patients will have a majority of hair removed after 5–10 treatments. A minority will have near complete removal and a small minority little or no improvement. Patients should also be aware of the potential need for future maintenance treatments. It is unclear whether such maintenance treatments are needed as a result of hair follicles emerging from a prolonged laser-induced telogen phase or of newly generated hair follicles. At the end of the consult, patients should be encouraged to ask questions or contact the office with any questions or concerns prior to scheduling the procedure. The overwhelming majority of patients with realistic expectations of what lasers can and cannot due for removing hair will be happy with their result. PREOPERATIVE All patients should be given a written informed consent to review. Common potential side-effects, posttreatment protocol, current medications, past medical history, and questions regarding the procedure and consent should be discussed. An active sunburn or inflammatory dermatosis increases the risk of blistering resulting in potential dyschromia or textural changes in the skin. Sunscreen use and sun protection prior to treatment and in the first 48 hours after treatment need to be emphasized to lower the risk of side- effects. A patient presenting to the office with a sunburn or active inflammatory dermatosis should be rescheduled. Fig.12.1 All individuals wear protective eye shields. The amount of pain associated with the procedure is a reflection of the density and caliber of hair follicles on the treated skin. Patients with thick, dense hair will experience pain with the procedure, while those with less density and finer hair will experience less pain.The perception of pain varies from individual to individual. The majority of patients undergo treatment with no anesthesia and tolerate the procedure well. Some require or request a topical anesthetic to reduce discomfort. Topical anesthetics should be used in safe quantities and as directed to minimize the risk of lidocaine toxicity.11 Local anesthetics should not be used in the region to be treated by a laser or light source, because the water in the dermis from the local anesthetic will be heated by the energy from the laser light, thereby increasing the risk of a blistering reaction, dyschromia, and textural changes in the skin. THE PROCEDURE Safety is paramount in the operation of all lasers (Fig. 12.1). Everyone in the procedure room should wear protective shields or goggles. Hair should be trimmed in the treated region to reduce the risk of epidermal changes secondary to thermal injury of follicles above the skin and to reduce the plume in the room. Careful attention should be paid to treat the entire surface of Carniol-12.qxd 6/1/2007 7:54 PM Page 135 Laser treatment for unwanted hair 135 Fig. 12.2 Poor cosmetic result secondary to lack of overlap of spot size when treating the back. the desired treatment zone by slightly overlapping each pulse (Fig. 12.2). It is vital that the appropriate use of the laser and cooling device be followed to reduce the risk of side-effects.12 Many lasers require firm contact with the skin for optimal efficacy and safety. Any operator of a laser should be thoroughly trained in the appropriate technique. Larger spot sizes will allow for a more rapid treatment and greater penetration of energy into the skin, and should be used wherever possible13 (Fig. 12.3). Immediately following the treatment, erythema and perifollicular edema are visible, which typically resolve in 30–60 minutes (Fig. 12.4). Postoperative instructions should be reviewed. Patients should be encouraged to contact the office if there is any crusting, blistering, dyschromia, pain after the procedure, or any questions or concerns.A follow-up procedure is typically scheduled in 4–12 weeks. Fig. 12.3 Larger spot sizes allow greater penetration of laser light. Fig. 12.4 Perifollicular edema immediately after treatment. COMPLICATIONS All medical procedures are associated with potential sideeffects. Laser hair removal is no exception. Every physician’s goal is to minimize any risk of sideeffects. The majority of complications can be avoided by a proper physical examinations, medical history, and appropriate preoperative instructions during the consultation. Common side-effects includes Carniol-12.qxd 6/1/2007 7:54 PM Page 136 136 Clinical procedures in laser skin rejuvenation Fig.12.5 Dyschromia secondary to inappropriate power and technique. transitory, crusting, superficial erosions and pseudo- folliculitis and temporary dyschromia (Figs. 12.5 and Table 12.2). Unusual complications include permanent dyschromia, scarring and paradoxical increased hair growth, ocular damage from operator error, infection, and vascular changes in the skin. All patients should be encouraged to contact the office and be seen as soon as possible if they believe they are having any side-effects after a procedure. Rapid medical intervention can often eliminate or substantially reduce the long-term effects of a complication. THE FUTURE Currently, laser hair removal is a safe, effective procedure. With appropriate candidate selection, expectations, and laser device, the vast majority of patients are happy with the results. A challenge remains to permanently remove unpigmented or lightly pigmented hair follicles. Several different technologies have been tried without consistent effective long-term permanent reduction of hair.14 Photodynamic therapy may become a treatment option. Effective, safe, affordable home devices may be another development in the field over the next several years. Ultimately, safe selective genetic manipulation of hair follicles where we want and where we do not want it on our skin will become a reality. Table 12.2 Complication from laser hair removal Common Unusual Transitory acne/folliculits Permanent dyschromia Transitory crusting Scarring Transitory dyschromia Paradoxical increase in hair Ocular damage Vascular changes Viral or bacterial infection REFERENCES 1. Avram MR, Cole JP, Gandelman M, et al. The potential role of monoxidil in hair transplantation setting. Dermatol Surg 2002;28:894–900. 2. Grossman MC, Dierickx C, Farinelli W, Flotte T, Anderson RR. Damage to hair follicles by normal-mode ruby laser pulses. J Am Acad Dermatol 1996;35:889–94. 3. Anderson RR, Parrish JA. Selective photothermolysis: precise microsurgery by selective absorption of pulsed radiation. Science 1983;220:524–7. 4. Anderson RR, Margolis RJ, Watenabe S, et al. Selective photothermolysis of cutaneous pigmentation by Q- switched Nd:YAG laser pulses at 1064, 532, and 355 nm. J Invest Dermatol 1989;93:28–32. 5. Astner S.Anderson RR.Treating vascular lesions. Dermatol Ther 2005;18:267–81. 6. Bernstein EF. Laser treatment of tattoos. Clin Dermatol 2006;64:850–5. 7. Azziz R. The evaluation and management of hirsutism. Obstet Gynecol 2003;101:995–1007. 8. Wanner M. Laser hair removal. Dermatol Ther 2005; 18:209–16. 9. Battle EF, Hobbs LM. Laser assisted hair removal for darker skin types. Dermatol Ther 2004;17:177–83. 10. Alajlan A, Shapiro J, River JK, et al. Paradoxical hypertrichosis. J Am Acad Dermatol 2005;53:85–8. 11. Brosh-Nissimov T,Ingbir M,Weintal I,Fried M,Porat R. Central nervous system toxicity following topical skin application of lidocaine. Eur J Clin Pharmacol 2004;60:683–4. 12. Klavuhn KG, Green D. Importance of cutaneous cooling during photothermal epilation: theoretical and practical considerations. Lasers Surg Med 2002;31:97–105. 13. Baumler W, Scherer K,Abels C, et al.The effect of different spot sizes on the efficacy of hair removal using a long- pulsed diode laser. Dermatol Surg 2002;28:118–21. 14. Sadick NS, Laughlin SA. Effective epilation of white and blond hair using combined radiofrequency and optical energy. J Cosmet Laser 2004;6:27–31.