sign in sign up
<<
Home , Aesthetic medicine, Intense pulsed light, Laser hair removal, Plucking (hair removal), Threading (epilation)

AESTHETIC FOCUS

Laser and based removal

BY PAOLO BONAN, MICHELA TROIANO, NICOLA BRUSCINO

Laser is a popular, and constantly evolving, treatment. Professor Paolo Bonan and colleagues provide us with a comprehensive overview and some ‘top tips’ for how to make the procedure as safe and effective as possible.

air removal, also known as removal in these sensitive areas may be during the whole hair cycle. For this epilation, is the deliberate very painful with wax or other traditional reason, targeting the hair follicles during a removal of body . Forms devices, so the employment of a laser or specific growth period, is considered to be Hof hair removal have been light-based technology is often preferred. unimportant. The previous theory about practised in almost all cultures the greater sensitivity of the anagen period since at least the Neolithic era, for various and light based hair was due to animal studies which showed a cultural, sexual, medical or religious removal: how they work maximum concentration of within reasons. Methods used to remove hairs Several laser and light devices are available anagen hairs [2-5]. have varied in different times and regions, on the market for hair removal: Photomechanical destruction, through including bleaching, , , (694nm), Alexandrite laser (755nm), diode the generation of shockwaves, has been , , chemical depilatories used by nanosecond Q-switched lasers, laser (800nm), (IPL) (eflornithine) and electrolysis; these employed during the early phase of laser (590-1200nm), neodymium-doped:yttrium methods can no longer be considered hair removal several years ago; these lasers aluminium garnet laser (Nd:YAG) (1064nm) ideal tools because of the limited and the are no longer considered because they and light-based devices for home use. short-term efficacy. There has, therefore, result in temporary . The purpose of these devices is the developed a great demand for efficient Photochemical destruction, through damage of stem cells in the bulge and long-term hair removal systems; in fact, the creation of toxic mediators such as dermal papilla of the by photoepilation by light and laser-based singlet oxygen or other free radicals, is targeting melanin which represents the systems is one of the fastest growing areas the approach followed by photodynamic specific [1-3]. Melanin of cosmetic . therapy (PDT); this could be a potential absorbs between 600-1100nm, Only a few patients require hair removal alternative technology since it may also the recommended optical window for for a purely medical purpose (these work on non-pigmented hairs. hair removal with the destruction of the include patients affected by , follicular unit. , cheloidalis nucae, Lasers and For such devices, three main pseudofolliculitis barbae), while most mechanisms of action have been undergo these procedures for purely IPL suggested: photothermal destruction, aesthetic reasons, mainly for the removal of IPL technology uses a xenon broadband photomechanical damage and unwanted hair from the face, trunk, limbs flashlamp to generate non-coherent photochemical process. and genital area. light in a spectrum between visible and Photothermal destruction of hair follicles If patients are affected by medical near (500-1200nm). To reach the constitutes the fundamental concept of troubles, they are highly motivated and desired chromophore, filters cut out the generally willing to undergo long and hair removal: melanin, the chromophore light emission according to the wavelengths painful procedures; when the approach contained inside the hair shaft, absorbs required by the ; consequently, is purely aesthetic, discomfort levels and the light energy converting it into heat, this type of light source can excite more the session’s duration can be important which spreads to the nearby bulge non- than one chromophore (haemoglobin, factors for the choice of the device and the pigmented stem cells, the target. The melanin, water). Handpieces have a large pathway of treatments. transfer of heat from the chromophore to surface of the spot, which is generally In particular, the genital zone is one the target is necessary for the effectiveness cooled, and application of gel on the of the most commonly treated body of the treatment. Recently it has been surface is required during epilation. Clinical areas; the so-called ‘Brazilian look’, which demonstrated that the anagen phase is endpoints, frequently seen during epilation involves complete removal of hairs from sensitive to laser and light pulses exactly by lasers, are not commonly observed with the vulva, perineum, anus, and buttocks, is as in the catagen and the telogen since IPL. Various studies have shown that IPL is a particularly popular current trend. Hair in the hairs remain pigmented inferior to Alexandrite and Nd:YAG lasers for long-term results [6-14].

Nd:YAG Nd-YAG long pulse is a laser source with “During the treatment, the laser / light emission should a longer and represents the first choice in darker skin patients always be matched with a cooling system” in our experience. According to several

pmfa news | APRIL/MAY 2017 | VOL 4 NO 4 | www.pmfanews.com AESTHETIC FOCUS

Figure 1A: Before starting on the inguinal areas. 1B: The results achieved after two Alexandrite laser sessions (Motus AX, Deka M.E.L.A. laser, Elen, Italy).

comparative studies Nd:YAG laser has been with melanin it is particularly indicated in the American market. Side-effects, like found to be less effective than Alexandrite in patients with low phototypes (up to hypopigmentation, have been reported and diode lasers, and more efficacious than 3-4) for the risk of burning resulting in after its use on dark skin. IPL and ruby laser as regards long-lasting hyper or hypo pigmentation. In order to hair removal results [6-14]. remedy this problem a new technology for Home devices photoepilation has recently been proposed. Home devices are characterised by lower Diode laser A new handpiece, with a cooled sapphire fluence compared with medical devices; Histological studies showed significant cylinder tip that conveys the laser beam this feature limits their effectiveness, since reduction in hair density and thickness onto the patient’s skin, has been introduced there is evidence of the capability of hair in skin treated with longer pulse 810nm onto the market. The use of this sapphire removal systems being fluence-dependent. diode laser. The long pulsed diode has guide dramatically reduces the system Conversely, the risks of adverse effects are been greatly used for hair removal due energy leaks to the skin, thus increasing reduced too. Nevertheless, the general to the efficacy and safety in patients with effectiveness of the laser transmission public often prefer investing their money Fitzpatrick skin phototypes I-V. Such lasers as never before (Figure 1). Working at low into these tools because they are cheap and are usually employed through an in-motion fluences makes the treatment painless pain free. manner, with several short pulses and a without undesirable side-effects. Repeated high frequency. Patients often consider this passages over the same area makes the Clinical features of the patient laser more tolerable than the long pulsed treatment uniform without leaving any area The main features to be evaluated are skin Nd:YAG [6-14]. untreated. phototype and hair. Shorter wavelengths are more absorbed by melanin, so for high Alexandrite laser Ruby laser phototypes lasers with a low wavelength Since 1997 the long pulse 755nm This was the first laser device selectively will result in a greater risk of burning and Alexandrite laser has been utilised with employed for hair removal, by Grossman consequently other unpleasant side- efficacy in laser hair removal. It allows in 1996 [15]. Compared to newer laser and effects; for these patients the selection of a deep penetration into the light-based modalities, the ruby laser is a diode laser or Nd:YAG laser is mandatory. allowing it to act on fair and black hair, less effective and in fact there are no long If the physician has a limited choice of however, because of its competition pulsed ruby lasers commercially available laser systems, it is possible to use a lower fluence, a longer pulse duration and a specific filter to make the treatment safer. Table 1: Contraindications to laser / light hair removal. Sometimes, for various reasons, patients cannot be treated with lasers or IPL devices Extreme tan Laser sessions should be delayed until the tanning has faded. (Table 1). Lack of melanin Poor results for blonde, white, grey hairs. Endocrine abnormalities May make the laser / light based treatments less effective. Preparation for the treatment Pregnancy No evidence of possible risks, but the treatment is not It is necessary to remind the patient to recommended for potential legal issues. avoid all epilation techniques for two to four weeks before the laser / light Autoimmune connective High photosensitivity. hair removal, otherwise it will provoke diseases elimination of the structure target of the Dermatological disorders Psoriasis, lichen planus and vitiligo may be triggered by a laser photoepilation. Shaving the hair by the with Koebner phenomenon / light employment. physician immediately before the beginning History of hypertrophic The laser / light sessions can evoke an impaired tissue repair of the treatment, or two to three days and keloids and subsequently scars and keloids. earlier by the patient, is adequate. If the Gold intake It can cause chrysiasis with cutaneous diffuse laser / light hair removal is not preceded by hyperpigmentations. shaving, the pulses absorbed by the long hairs could induce burning of the skin. We Isotretinoin Six to 12 months of washout time after oral isotretinoin, usually prefer to do the shaving ourselves, otherwise there are risks of skin fragility, delay in since we can better evaluate the diameter reepithelisation, hyperpigmentations and scars. and the pigmentation of the hairs cut, and

pmfa news | APRIL/MAY 2017 | VOL 4 NO 4 | www.pmfanews.com AESTHETIC FOCUS

these features affect the parameters to be discomfort for the patient due to the effects, such as thermal burns, blisters, chosen. possible unpleasant sensation on a larger , hypopigmentation part of the body [16-18]. and scarring, can occur. Severe side-effects Selection of the parameters manifest more frequently in darker-skinned The fluence (J/cm2) determines the Treatment protocol patients but can be avoided or minimised temperature achieved within the follicular During the treatment, the laser / light by the selection of safer parameters and an stem cells in the bulge while the pulse emission should always be matched with effective cooling process during the session. duration corresponds to the time length of a cooling system; this is important for all ‘Paradoxical hypertrichosis’ is a rare side- that reached temperature. The energy level, phototypes, but vital in those persons with effect observed in patients treated by IPL, the fluence, changes for each laser and more epidermal melanin. Cryogen spray, diode and Alexandrite lasers, when the IPL device according to their output range cold air, and direct contact cooling are laser or light stimulates the growth of new features, however, the physician should commonly employed in combination with hairs through a photoactivation of dormant lasers and IPL [19]. select the highest value without eliciting hair follicles into terminal anagen hair side-effects in the skin, since high fluences phase. It is characterised by the appearance are correlated with greater permanent hair Clinical endpoints of new hair follicles surrounding the treated removal. Normally, the fluence is inversely Clinical therapeutic endpoints are areas. This side-effect could be induced by proportional to the pigmentation of the immediate or early cutaneous reactions the selection of excessively conservative hairs to be removed, e.g. darker hairs that take place during a laser session; parameters, and therefore it can be solved require lower fluence while brighter hairs they may guide the physician in delivering by more aggressive parameters during the need higher fluence. safe and effective laser / light treatment. subsequent sessions [20-21]. According to the selective The most relevant clinical endpoint for phothermolysis theory the pulse duration laser and IPL hair removal is perifollicular should approximately correspond to erythema and oedema, which corresponds Conclusion the thermal relaxation time (TRT) of the to an eosinophilic inflammatory reaction Laser hair removal is a popular treatment, chromophore, but for laser-based hair due to the hair injury. This endpoint and therefore its techniques are evolving. removal the chromophore, melanin, and typically appears a few minutes after the According to previous comparative studies the laser biological target, stem cells of laser / IPL passage and this immediate skin laser and light-based systems for hair the follicle bulge, do not correspond. This response gives evidence of the effectiveness removal are shown to be generally safe requires a laser pulse duration longer of the treatment. and efficacious if employed by experienced than if the chromophore and the target The pigmented hairs vaporise releasing practitioners. The differences between were identical; we apply the concept of a typical smell of smoke due to the burnt these systems include the time length thermal damage time (TDT), allowing the keratin. The thin hairs behave in a different of every session, the discomfort felt by conduction of thermal damage to the manner after the laser / light emission: the patient, the possibility of treating follicular stem cells. As a result, 10-100ms they can enlarge the tip or turn white at the darker patients, and the cost of a single laser or IPL pulses are usually needed, follicular ostium. treatment. New hair removal systems could while shorter pulse times are indicated include promising portable home devices, for thinner hairs. In the cases of dark Results photopneumatic technologies, PDT and phototypes the pulse duration should A permanent dropout of hair follicles is bipolar radiofrequency. Clinical studies increase for achieving a sort of epidermal reached in 15-30% of laser / light treated and long-term data will be necessary to protection to all the possible risks. hairs at each session, while the majority of determine the effectiveness and the safety The patient with a high phototype with treated hairs fall into a telogen-like state of these modalities from the future. thin and bright hairs presents a serious characterised by rest and absence of hair challenge for hair removal practitioners, growth. This telogen-like state explains a as this type of hair would require a great short-lasting period of alopecia, usually References fluence and a short pulse whereas the skin lasting for a few months, until some hair 1. Choudhary S, Elsaie ML, Nouri K. Laser assisted hair type would require a low fluence and a long follicles begin another anagen cycle. removal. G Ital Dermatol Venereol 2009;114:595-602. pulse duration. Erythema frequently occurs and the 2. Kolinko VG, Littler CM, Cole A. Influence on anagen:telogen ratio on Q switched Nd:YAG laser Another relevant fact to be considered employment of a topical steroid for two hair removal efficacy.Laser Surg Med 2000;26:33-40. to three days is enough to eliminate this is the progressive reduction of the hair 3. Seago SV, Ebling FJ. The hair cycle in human thigh diameter with the laser / light sessions, temporary side-effect. The patient must and upper arm. Br J Dermatol 1985;113:9-16. so the physician may need to change the always remember to avoid sun exposure 4. Randal VA, Ebling FJ. Seasonal changes in human parameters being used. and to apply sunscreen for several days hair growth. Br J Dermatol 1991;124:146-51. The spot size influences the penetration days following the session. 5. Hughes CL. ‘Hirsutism’ In: Olsen EA (Ed). Disorders of depth of light, since a bigger spot size hair growth: diagnosis and treatment. New York, USA: McGraw Hill; 1994:337-50. penetrates deeper for a reduced scattering Possible side-effects 6. Gan SD, Graber EM. Laser hair removal: a review. phenomenon. A larger spot size allows the The most common cutaneous reactions Dermatol Surg 2013;39:823-38. practitioner to cover the area to be epilated include erythema, oedema, discomfort, 7. Haedersal M, Haak CS. Hair removal. Curr Probl rapidly, but this can lead to increased pain, and occasionally more severe side- Dermatol 2011;42:111-21. 8. Kutlubay Z. Alexandrite laser hair removal results in 2359 patients: a Turkish experience. J Cosmet Laser Ther 2009;11:85-93. 9. Khoury JG, Saluja R, Goldman MP. Comparative evaluation of long-pulse Alexandrite and long-pulse “Cryogen spray, cold air, and direct contact cooling are Nd:Yag laser systems used individually and in combination for axillary hair removal. Dermatol Surg commonly employed in combination with lasers and IPL [19]” 2008;34:665-70.

pmfa news | APRIL/MAY 2017 | VOL 4 NO 4 | www.pmfanews.com AESTHETIC FOCUS

10. Cannarozzo G, Bonan P, Campolmi P. Epilation with Nd:YAG laser: a brief analysis of the technical application methods, result and pre- and post- AUTHORS treatment procedures. J Cosmetic Laser Ther “Severe side-effects manifest 2003;5:189-91. 11. Ismail SA. Long-pulsed Nd:YAG laser vs. Intense more frequently in darker- Pulsed Light for hair removal in dark skin: a randomized controlled trial. Br J Dermatol skinned patients but can be 2012;166:317-21. 12. Baugh WP, Trafeli JP, Barnette DJ Jr, Ross EV. Hair avoided or minimised by the reduction using a scanning 800nm diode laser. Dermatol Surg 2001;27:358-64. selection of safer parameters 13. Finkel B, Eliezri YD, Waldman A, Slatkine M. Pulsed Alexandrite laser technology for noninvasive hair and an effective cooling removal. J Clinic Laser Med Surg 1997;15:225-9. 14. Faurschou A, Haedersdal M. ‘Photoepilation of Paolo Bonan, process during the session“ unwanted hair growth’ in: Raulin C, Karsai S (Eds). Head of Dermatology, Laser Cutaneous Cosmetic Laser and IPL technology in dermatology and & Unit, at the Villa Donatello Clinic . Berlin, Germany: Springer-Verlag; in Florence; Professor at the Post-Graduate School 2011:125-46. of Dermatology for Dermatological Physiotherapy, 15. Grossman MC, Dierickx C, Farinelli W, et al. Damage Department of Dermatology, University of Florence; to hair follicles by normal-mode ruby laser pulses. J and Professor at Marconi University in Rome, Italy. Am Acad Dermatol 1996;35:889. E: [email protected] Declaration of competing interests: None declared. 16. Ibrahimi OA, Avram MM, Hanke CW, et al. Laser hair removal. Dermatol Ther 2011;24:94-107. 17. Serrano-Grau P, Campo-Voegeli A, Romero D. Fotoepilacion. Actas Dermosifiliogr 2009;100:351-61. 18. Haedersdal M, Beerwerth F, Nash JF. Laser and intense pulsed light hair removal technologies: from professional to home use. Br J Dermatol 2011;165:31- 6. 19. Ram R, Rosenbach A. Effects of ambient room temperature on cold air cooling during laser hair removal. J Cosmet Dermatol 2007;6:203-6. 20. Rasheed AI. Uncommonly reported side effects of hair removal by long pulsed Alexandrite laser. J Michela Troiano, Nicola Bruscino, Cosmet Dermatol 2009;8:267-74. 21. Alajlan A, Shapiro J, Rivers JK, et al. Paradoxical Dermatologist, Laser Cutaneous Cosmetic & Plastic Dermatologist, Laser Cutaneous Cosmetic & Plastic hypertrichosis after laser epilation. J Am Acad Surgery Unit, at the Villa Donatello Clinic in Florence, Surgery Unit, at the Villa Donatello Clinic in Florence, Dermatol 2005;53:85-8. Italy. Italy.

pmfa news | APRIL/MAY 2017 | VOL 4 NO 4 | www.pmfanews.com