Laser and photoepilation for unwanted hair growth (Review)

Transcription

1 Haedersdal M, Gøtzsche PC This is a reprint of a Cochrane review, prepared and maintained by The Cochrane Collaboration and published in The Cochrane Library 2009, Issue 1

2 T A B L E O F C O N T E N T S HEADER ABSTRACT PLAIN LANGUAGE SUMMARY BACKGROUND OBJECTIVES METHODS RESULTS DISCUSSION AUTHORS CONCLUSIONS ACKNOWLEDGEMENTS REFERENCES CHARACTERISTICS OF STUDIES DATA AND ANALYSES APPENDICES WHAT S NEW HISTORY CONTRIBUTIONS OF AUTHORS DECLARATIONS OF INTEREST SOURCES OF SUPPORT INDEX TERMS i

3 [Intervention Review] Laser and photoepilation for unwanted hair growth Merete Haedersdal 1, Peter C Gøtzsche 2 1 Dept. of Dermatology D-92, Bispebjerg Hospital, Copenhagen, Denmark. 2 The Nordic Cochrane Centre, Rigshospitalet, Dept. 3343, Copenhagen Ø, Denmark Contact address: Merete Haedersdal, Dept. of Dermatology D-92, Bispebjerg Hospital, Bispebjerg Bakke 23, Copenhagen, 2400 NV, Denmark. mhaedersdal@dadlnet.dk. mhaederdal@dadlnet.dk. Editorial group: Cochrane Skin Group. Publication status and date: Edited (no change to conclusions), published in Issue 1, Review content assessed as up-to-date: 30 July Citation: Haedersdal M, Gøtzsche PC. Laser and photoepilation for unwanted hair growth. Cochrane Database of Systematic Reviews 2006, Issue 4. Art. No.: CD DOI: / CD pub2. Background A B S T R A C T Unwanted hair growth is a therapeutic challenge and considerable resources are spent to achieve a hair-free appearance. Epilation with laser devices (alexandrite, diode, neodymium:yag, and ruby lasers) and intense pulsed light are commonly used although the longterm effect is uncertain. Objectives To assess the effects of epilation with lasers and light sources. Search methods We searched the Cochrane Skin Group s Specialised Register in February 2004; MEDLINE (from 1966) and EMBASE (from 1980) in April We searched reference lists of collected trials and contacted trial authors. Selection criteria Randomised controlled trials of laser or photoepilation. Data collection and analysis Primary outcomes were objective reduction in hair counts, adverse effects and subjective reduction in hairiness. Secondary outcomes were participants satisfaction and personal observations such as softer, finer, or paler hairs. Two authors independently extracted data and assessed trial quality. Main results We included eleven randomised controlled trials involving 444 people, none of which were of high methodological quality. A large number of trials were excluded, mainly because of their non-randomised design. The randomisation procedures were either unclear or inadequate, using coin tossing, alternation, drawing lots or cards, or open tables of random numbers. The interventions and outcomes were too heterogeneous to be entered in a meta-analysis. Most trials examined a short-term effect up to six months after final treatment. There appeared to be a short-term effect of approximately 50% hair reduction with alexandrite and diode lasers up to six months after treatment, whereas little evidence was obtained for an effect of intense pulsed light, neodymium:yag or ruby lasers. Long-term hair removal was not documented with any treatment. Pain, skin redness, swelling, burned hairs and pigmentary changes were infrequently reported adverse effects. 1

4 Authors conclusions Some treatments lead to temporary short-term hair removal. High quality research is needed on the effect of laser and photoepilation. P L A I N L A N G U A G E S U M M A R Y Unwanted hair removal by laser systems and intense pulsed light sources Unwanted hair growth is a challenge and considerable resources are spent to achieve a hair-free appearance. Hair removal with laser devices (alexandrite, diode, neodymium:yag, and ruby lasers) and intense pulsed light are widespread methods for hair removal although the long-term effect is uncertain. Eleven randomised controlled trials were included in the review, none of which were of high quality. A large number of trials were excluded, mainly because of their non-randomised designs. There appeared to be a short-term effect of approximately 50% hair reduction with alexandrite and diode lasers up to six months after treatment, whereas there was little evidence for an effect with intense pulsed light, neodymium:yag or ruby lasers. Long-term hair removal was not recorded for any treatment. Infrequently reported adverse effects were pain, skin redness, swelling, burned hairs and pigmentary changes. B A C K G R O U N D Demands for efficient hair removal Millions of people all over the world remove unwanted hair at regular intervals and considerable amounts of time and money are spent in order to achieve a hair-free appearance. Traditional treatments include shaving, plucking, waxing, chemical depilatories, and electrolysis (Olsen 1999). None of these methods are ideal as their effects are short-term. Furthermore, the treatments may be tedious and adverse effects can occur which include pain, skin redness, swelling, blistering, crusting, infection, allergic eczema, decreased and increased skin pigmentation, as well as scarring (Hædersdal 1999; Liew 1999; Liew 2002; Nanni 1999). Increasing consumer demand for better hair removal has led to newer treatment techniques with laser devices and intense pulsed light (IPL). These are today considered the most efficient methods for removal of unwanted hair (Dierickx 2002; Goldberg 2002; Liew 2002). Clinical presentation of unwanted hair growth Excess hair growth covers a broad range of severity and may present as hypertrichosis or hirsutism. Hypertrichosis is defined as excess hair at any body site, whereas hirsutism denotes excess hair growth in women at sites where only men normally develop coarse hair, primarily the face and neck around the beard area and sideburns as well as the escutcheon hair pattern in the pubic area. However, hair removal treatments are most often performed for cosmetic reasons in people with normal hair growth. Laser systems and intense pulsed light sources for hair removal Laser and photoepilation means hair removal by laser systems and Intense pulsed light (IPL) sources. Over recent years, several devices have been developed which are now offered as standard treatments for unwanted hair growth. The available lasers and light sources operate in the red or near-infrared wavelength regions: ruby lasers (694 nm), alexandrite lasers (755 nm), diode lasers (800, 810 nm), neodymium:yttrium-aluminium-garnet (Nd:YAG) lasers (1064 nm), and IPL sources (590 to 1200 nm) (Alster 2001; Bjerring 2000; Görgü 2000; Lou 2000). The physical parameters used with these treatment systems vary considerably. However, all treatments using laser systems and IPL sources are based on the same concept, the theory of selective photothermolysis, which is an optimal interaction between light and skin whereby selected skin structures are targeted without damaging adjacent skin structures (Anderson 1983). Selective photothermolysis is possible when melanin pigment in the hair follicles absorbs the wavelengths selected and the pulse duration is shorter than the time it takes for the heat to dissipate from the hair follicle into the surrounding tissue. The hair follicles are selectively destroyed by thermal damage and future hair growth is impaired (Altshuler 2001; Grossman 1996). 2

5 Why it is important to do this review The large demand for removal of unwanted hair and the increasing use of laser and photoepilation calls for a critical appraisal of the benefits and harms of these newer techniques. Preliminary examination of the literature suggests a wide variation in the quality of studies evaluating laser and IPL and that the long-term effect is uncertain, which underlines the need for a systematic review of the most reliable studies. O B J E C T I V E S To assess the effects of epilation with lasers and light sources. M E T H O D S Types of outcome measures Primary outcomes (a) Objective reduction in hair counts determined by serial measurements of the treated areas. Hair counts were dichotomised and we considered a reduction of at least 50% a worthwhile clinical change. (b) Adverse effects, e.g. erythema, crusts, hyperpigmentation, hypopigmentation, and textural changes (defined as any clinical change in skin consistency and texture, including atrophic and hypertrophic scarring). (c) Subjective reduction in hairiness determined by overall impression. Measures of hairiness were dichotomised and we considered a reduction of at least 50% a worthwhile clinical change. In the protocol for our review, this outcome was considered a secondary one. We changed it according to a suggestion by the editors. Criteria for considering studies for this review Types of studies Randomised controlled trials (RCTs). RCTs with more than one treatment applied to the same individual or with only one treatment per individual, with or without observer blinding. Participant blinding was almost impossible to obtain and was, therefore, not a requirement for inclusion. Types of participants People with hirsutism and hypertrichosis as well as people with unwanted hair growth. Volunteers treated for experimental purposes were also included. Types of interventions (1) Experimental Any laser or light source (e.g. ruby laser, alexandrite laser, Neodymium:YAG laser, diode laser, and IPL source), including single treatment versus repetitive treatments. Secondary outcomes (a) Participants satisfaction. (b) Participants personal observations such as softer, finer, or paler hairs. Hair counts, hairiness, and adverse effects were assessed from on-site clinical examinations or from photographs. Global improvement scales were sometimes used to evaluate hairiness, participants satisfaction and personal observations. We considered hair reduction between one and six months after treatment as short-term and beyond six months postoperatively (preferably more than 12 months) as long-term. The distinction between short- and long-term hair reduction is based on the growth cycle of hair. In order to evaluate the true effect of any interventions, the trial period has to exceed the duration of the growth cycle in the treated area. The growth cycle can be divided into three phases, anagen (active growing phase), catagen (involutional stage), and telogen (resting phase) with the duration of phases and the distribution of hairs varying within different anatomical regions. Examples of growth phases are estimated as 1 to 2 months in thighs, 4 to 6 months in legs, 2 to 5 months on the upper lip, 12 months in the beard region, and 2 to 6 years in the scalp (Olsen 1999). Search methods for identification of studies (2) Control (a) Placebo. (b) No treatment. (c) Traditional treatments (e.g. shaving, waxing, and electrolysis). (d) Lasers or light sources different from the experimental intervention. Electronic searches We searched the following databases: The Cochrane Skin Group s Specialised Register on 12 February 2004 using the terms in Appendix 1, 3

6 MEDLINE (Silver Platter) in April 2005; this database was searched from 1966 in April 2005 using the strategy in Appendix 2. EMBASE; this database was searched from 1980 in April 2005 using the search strategy in Appendix 3 Searching other resources References from published studies These were checked for further trials. Unpublished literature On-going trials and grey literature were obtained via correspondence with trial authors. Language restrictions No language restrictions were imposed and translations were sought when necessary. Data collection and analysis Selection of studies One author (MH) checked the titles and abstracts identified from the searches. Both authors independently evaluated the full text of all trials of possible relevance. The authors decided which trials fulfilled the inclusion criteria and recorded their methodological quality. Any disagreements were resolved by discussion. Data extraction and management The authors independently performed data extraction; differences were resolved by discussion. We contacted the trial authors if any data or other important information were missing. We used PubMed and abstract books to obtain the trial authors most recent addresses. Assessment of risk of bias in included studies Assessment of methodological quality The following three areas were addressed: (a) randomisation (method of generation and concealment of allocation); (b) blinding of observers; (c) exclusions after randomisation and losses to follow up. Trials were considered high-quality if they had adequate allocation concealment, blinded observers, and applied an intention-totreat analysis, or data were available from the publication which allowed for the intention to treat analysis to be performed. Trials were considered of poor quality if they had inadequate allocation concealment, unblinded observers, and exclusions were not accounted for after randomisation. Concealment of allocation is the most important and sensitive indicator that bias has been minimised in a clinical trial (Schulz 1995). We considered concealment adequate if there was: central randomisation; serially numbered, opaque, sealed envelopes; other descriptions that contained elements of convincing concealment of allocation. We considered trials as non-randomised if randomisation was not mentioned in the abstract or the methods section. Unclear concealment meant that there was no description of the method, or that the description did not allow a clear distinction between adequate and inadequate concealment. Concealment was inadequate if there was: alternation; reference to case record numbers or date of birth; an open table of random numbers. If no information was given about blinding we assumed the trial was not blinded. The trial authors were contacted for clarification. Data synthesis The data were much too heterogeneous and too poorly reported to be entered in a meta-analysis. Interventions and treatment protocols were very different, e.g. as concerns trial design, equipment, physical settings, number of treatments, and participants hair and skin characteristics. We therefore present the results from the individual trials in a narrative fashion. Data on adverse effects are similarly described qualitatively. R E S U L T S Description of studies See: Characteristics of included studies; Characteristics of excluded studies. Results of the search We identified 38 potentially relevant studies. The primary outcomes objective reduction in hair counts (Allison 2003; Fiskerstrand 2003; Handrick 2001; Hussain 2003; Nanni 1997; Nouri 2004) and subjective reduction in hairiness (Clayton 2005; Goh 2003; Handrick 2001; Lehrer 2003; Nanni 1997) were evaluated in six and five trials, respectively. Adverse effects were evaluated in two trials as the only outcome measure (Eremia 2000; Haedersdal 1999) and in nine trials in addition to the beneficial outcomes (Allison 2003; Clayton 2005; Fiskerstrand 2003; Goh 4

7 2003; Handrick 2001; Hussain 2003, Lehrer 2003; Nanni 1997; Nouri 2004). The secondary outcomes participant satisfaction and participants personal observations such as softer, fines, or paler hairs were not evaluated in any trials. Included studies For a full description of included trials see Characteristics of included studies. Eleven RCTs were included with the following interventions: Allocation The randomisation method was inadequate or unclear in all trials. None of the trials described adequate allocation concealment; inadequate methods included coin tossing (Allison 2003; Lehrer 2003), alternation (Eremia 2000; Fiskerstrand 2003), drawing lots from an open envelope (Goh 2003), card draw (Handrick 2001; Nanni 1997), and open tables of random numbers (Clayton 2005; Haedersdal 1999). The randomisation and concealment of allocation was unclear in two trials (Hussain 2003; Nouri 2004). (1) Laser and photoepilation versus no treatment or placebo - two RCTs High-dose alexandrite laser versus sham (low-dose) alexandrite laser (Clayton 2005) or no treatment (Nouri 2004). (2) Lasers and light sources versus each other - three RCTs Two different types of diode lasers (Fiskerstrand 2003). Nd:YAG laser versus IPL (Goh 2003). Alexandrite laser versus diode laser (Handrick 2001). Blinding Blinding of outcome assessments Outcome assessments were evaluated blindly in 8 of the 11 RCTs (Clayton 2005; Fiskerstrand 2003; Haedersdal 1999; Handrick 2001; Hussain 2003; Lehrer 2003; Nanni 1997; Nouri 2004). Blinding of outcome assessment was performed by blinded photographic evaluations (Fiskerstrand 2003; Hussain 2003; Lehrer 2003; Nanni 1997; Nouri 2004), by blinded on-site evaluations (Clayton 2005; Haedersdal 1999), or both (Handrick 2001). (3) Variations in physical settings and treatment numbers - four RCTs Different doses with diode laser (Handrick 2001). Different spot sizes with alexandrite laser (Nouri 2004). Two versus three treatments with ruby laser (Allison 2003). One versus two versus three treatments with alexandrite laser (Hussain 2003). (4) The importance of pretreatment conditions - two RCTs Alexandrite (Lehrer 2003) or Q-switched Nd:YAG (Nanni 1997) laser with and without preoperative wax epilation. Excluded studies We excluded 27 studies, mainly because they were not randomised. For a full description of excluded trials see Characteristics of excluded studies. Risk of bias in included studies None of the trials were of high methodological quality and most were of poor quality. We contacted corresponding trial authors and obtained responses from half (see Acknowledgements ). Nine trials were within-participant studies and two were parallel-group trials (Clayton 2005; Hussain 2003). For a full description of these trials, see Characteristics of included studies. Incomplete outcome data Exclusions Eight trials gave adequate descriptions of dropouts and withdrawals (Clayton 2005; Fiskerstrand 2003; Goh 2003; Haedersdal 1999; Handrick 2001; Lehrer 2003; Nanni 1997; Nouri 2004). In five trials, all randomised participants completed the trial period (Goh 2003; Haedersdal 1999; Handrick 2001; Lehrer 2003; Nanni 1997), and one trial mentioned intention-to-treat analysis (missing values were carried forward from baseline data) (Clayton 2005). In the other trials it seemed that only those participants who completed the trial were included in the analyses. Trial periods Eight trials examined a short-term effect up to six months after treatment (Allison 2003; Clayton 2005; Fiskerstrand 2003; Goh 2003; Handrick 2001; Lehrer 2003; Nanni 1997; Nouri 2004). One study evaluated the effect nine months after treatment (Hussain 2003). No trials extended their observations beyond one year. Four trials examined immediate and short-term adverse effects (Eremia 2000; Fiskerstrand 2003; Goh 2003; Handrick 2001) and three trials followed adverse effects during three (Haedersdal 1999), six (Handrick 2001) and nine months (Hussain 2003) after treatment. 5

8 Effects of interventions We included eleven trials, involving 444 participants. The interventions and outcomes were too heterogeneous to be entered in a meta-analysis. Long-term hair reduction Limited data were available on long-term hair reduction from one parallel-group trial with unclear randomisation (Hussain 2003). The trial compared one treatment, using the alexandrite laser, with either two or three treatments given at monthly intervals. A total of 256 treatment sites in the axilla, arms and legs were used in 144 Asian participants with skin types III to V. At nine months after final treatment, hair reductions were 55% (three treatments), 44% (two treatments) and 32% (one treatment). These data were difficult to interpret as there were no measures of dispersion or statistical tests, dropouts were not accounted for, and some participants contributed with more than one test area, which mixes up within and between participant variations. Short-term hair reduction A short-term effect of up to six months after treatment was evaluated in one parallel-group and seven within-participant trials with unclear (Nouri 2004) or inadequate randomisation (Allison 2003; Clayton 2005; Fiskerstrand 2003; Goh 2003; Handrick 2001; Lehrer 2003; Nanni 1997). One trial evaluated the short-term effect of laser treatment versus sham treatment (Clayton 2005). This trial (n = 88) compared high-fluence alexandrite laser treatments (mean fluence 23.6 J/cm 2, mean of 4.8 treatments) with low-dose sham treatments (fixed fluence 4.8 J/cm 2, mean of 4.4 treatments) in hirsute women with polycystic ovary syndrome within a six-month study period and response evaluation one to two months after final treatment (Clayton 2005). The randomisation was not concealed. Significant improvements were seen in the intervention group versus the control group for self-reported severity of facial hair (reduction from 7.3 to 3.6 versus 7.1 to 6.1 on a scale 1 to 10), time spent on hair removal (reduction from 112 to 21 min. per week versus 92 to 56 min.), mean depression scores (reduction from 6.7 to 3.6 versus 6.1 to 5.4 on a scale 0 to 21), mean anxiety scores (reduction from 11.1 to 8.2 versus 9.6 to 9.3 on a scale 0 to 21), and psychological quality of life (improvement from 49.6 to 61.2 versus 50.1 to 51.5, scale not reported). Long-term hair removal was not evaluated. Three trials compared lasers and light sources with each other (Fiskerstrand 2003; Goh 2003; Handrick 2001). The first trial (n = 41) compared the effect of two long pulsed diode lasers with different pulse structures (Fiskerstrand 2003). Three treatments were given, to the upper lip, with each laser at six to eight week intervals. Only 29 participants completed the study. Six months after the final treatment, average hair reductions of 49% (810 nm MedioStar ) and 48% (800 nm LightSheer ) were found. The second trial (n = 11) compared a single treatment of IPL with a long pulse Nd:YAG laser in participants with darker skin types IV - VI (Goh 2003). Treatments were given to axilla, legs and faces with one half of the body randomly treated with Nd: YAG or IPL. Self-reported reductions in hairiness were no better than 20%, which was obtained in 7 and 8 of IPL and Nd:YAG laser treated participants, respectively. The third trial (n = 20) compared alexandrite with diode lasers (Handrick 2001). Clinical improvement scores were similar six months after three treatment sessions and hair counts were also similar (mean hair regrowth varied between 54% and 63%). One trial (n = 17), using the alexandrite laser, compared different laser spot sizes (Nouri 2004). Three treatments were given at six week intervals to axilla regions, and hair reductions of 52% (18 mm spot size) and 42% (12 mm spot size) were obtained six months after final treatment (no significant difference). The study had many drop-outs (6 of 17 participants) which were not accounted for. It also had an untreated control group but no data were given. Another trial (n = 69) evaluated the effect of two versus three monthly treatments with the ruby laser with data presented up to five months after final treatment (Allison 2003). However, the study was not adequately randomised, e.g. 7 left axillas versus 18 right axillas were treated three times and number of sides also varied substantially, although they should be identical since it was a within-participant trial; finally, data were missing for up to half of the participants. Two trials evaluated the importance of varying pretreatment conditions (Lehrer 2003; Nanni 1997). The first trial (n = 13) examined the effect of wax epilation before one treatment with the alexandrite laser (Lehrer 2003). The outcome used was a subjective overall impression of the reduction in hairiness one month after treatment. Blinded observers compared photos of laser treated squares with or without pre-waxing and decided which area looked better. In 12 of 13 participants, pretreatment with wax epilation resulted in more intense clearance of hair as compared with alexandrite laser treatment alone. The other trial (n = 12) evaluated the effect after one treatment with a Q-switched Nd:YAG laser with and without preoperative wax epilation and carbon solution (Nanni 1997). Hair regrowth was delayed at one and three months in areas treated only with laser (mean regrowth 66% and 86%) whereas wax epilation resulted in mean regrowth of 78% and 102%. Preoperative waxing tended to improve the effect at one month (mean regrowth 47%) whereas similar regrowth was seen at three months (mean regrowth 85%). After six months, full regrowth was observed in all test areas, both objectively, and as evaluated subjectively by the participants. Adverse effects Adverse effects were evaluated in two trials as the only outcome measure (Eremia 2000; Haedersdal 1999) and in the other nine 6

9 trials in addition to the beneficial outcomes (Allison 2003; Clayton 2005; Fiskerstrand 2003; Goh 2003; Handrick 2001; Hussain 2003, Lehrer 2003; Nanni 1997; Nouri 2004). One of the studies of adverse effects evaluated pain from alexandrite and diode lasers, but the number of participants in the analyses, the number of drop-outs, and the score system for assessing pain were all unclear (Eremia 2000). In the other study, pigmentary alterations and texture changes were evaluated 12 weeks after one treatment with the ruby laser at three fluence levels versus an untreated control area (n=17) (Haedersdal 1999). Hypopigmentation was the most frequently observed adverse effect, occurring in 5 of 51 laser treated areas and in 1 of 17 untreated control areas. Hyperpigmentation occurred in 1 of 51 laser treated areas and none of 17 untreated control areas. No texture changes were observed in any test areas. Two participants out of 69 had superficial burns and depigmentation, and one reactivation of herpes on the ruby laser (Allison 2003). More women felt pain or discomfort when treated with the alexandrine laser than with sham laser (Clayton 2005). No scarring or pigmentary changes occurred, but more intense skin redness (erythema) (P < 0.001) and burned hairs (P < 0.001) were noted with the 800 nm diode laser than with the 810 nm diode laser (Fiskerstrand 2003). Seven of 11 participants felt pain after Nd:YAG laser and after IPL (Goh 2003), described as a pinprick sensation and a prolonged burning sensation, respectively, three participants developed blisters and five participants developed postinflammatory pigmentation after IPL treatment whereas none of these adverse effects were seen after Nd:YAG laser treatment. Three of twelve participants developed transient folliculitis after treatment with a Nd:YAG laser (Nanni 1997). More pain was noted with the diode laser than with the alexandrite laser and two participants developed transient hyperpigmentation with the diode laser (Handrick 2001). No adverse effects were reported in one trial (Nouri 2004). In the remaining trials, adverse effects were not divided by treatment groups (Hussain 2003; Lehrer 2003). D I S C U S S I O N Treatment techniques in laser and photoepilation cover a broad range of laser and IPL devices from different manufacturers, including several wavelengths, pulse durations and pulse configurations, different spot sizes, skin cooling, and fluence levels. Moreover, a variety of treatment protocols has been used with different numbers of treatments and varying intervals between treatments. There is also great variation in trial participants related to skin and hair characteristics such as skin pigmentation, hair colour, hair thickness, hair growth cycle, anatomical region and depth of follicles, as well as endocrine dysfunction, which may influence the treatment outcome. All of these variables contribute to the confusion among practitioners and the general public regarding the true efficacy and limitations of laser and IPL-assisted hair removal. Unfortunately, the majority of the trials had short follow-up periods. Furthermore, all trials included in this review were of low methodological quality, although it could be argued that concealment of allocation might be less important for within-participant trials where the investigators have little incentive for choosing one side of the body or another for their preferred treatment. Due to the fact that none of the available trials were of high methodological quality, it could be argued that the true efficacy from laserand photoepilation may not be answered until high quality trials are published. A large number of non-randomised controlled studies on the efficacy of laser and IPL hair removal have been reviewed elsewhere (Hædersdal 2006; Sanchez 2002). Some of these studies were designed as within-participant trials with left-right comparisons (Bjerring 2000; Boss 1999; Chan 2001; Elman 2000; Görgü 2000; Rogers 1999), which may, on average, be less biased than nonrandomised parallel-group studies. Some of the non-randomised studies had long-term follow-up times (Baumler 2002; Eremia 2001; Lorenz 2002; Lou 2000). One of these studies compared one to four treatments with the long pulsed Nd:YAG laser with an untreated control. One year after the final treatment, more than 50% hair reduction was still present in 40% of areas treated five times versus none of the untreated control areas or areas treated once (Lorenz 2002). In another study, the effect of a diode laser (n = 50) was significantly better than that of shaving, and two repetitive treatments (34% to 53% hair reduction) were superior to a single treatment (28% to 33% hair reduction) at an average follow-up of 20 months after final treatment (Lou 2000). Another study found similar effects of repetitive treatments (three to four treatments) with the alexandrite laser (n = 15) and the diode laser (hair reductions of 85% and 84%, respectively) at the 12 month follow up (Eremia 2001). Moreover, a study compared alexandrite laser with electrolysis (Görgü 2000). Three treatments with the alexandrite laser (mean 74% reduction) were more efficient than four treatments of electrolysis (mean 35% reduction) six months postoperatively and all 12 participants preferred laser treatment to electrolysis due to better effect and less pain (Görgü 2000). It is important that people seeking removal of unwanted hair and laser practitioners have realistic expectations of the treatment outcome from laser and photoepilation. Several manufacturers have received the Food and Drug Administration s (FDA) permission to claim permanent hair reduction ( laserfacts.html). Permanent hair reduction is in this context defined as a long-term, stable reduction in the number of hairs regrowing after a treatment regimen, which may include several sessions. The number of regrowing hairs must be stable over a time greater than the duration of the complete growth cycle of hair follicles, which varies from 4 to 12 months according to the body location. Permanent hair reduction does in the FDA context not necessarily imply the elimination of all hairs in the treatment area. It is confusing for consumers that permanent hair reduction does 7

10 not really mean permanent hair reduction. As might be expected, the message has often been distorted in newspapers and advertisements that promise permanent hair removal. This misrepresentation of the facts may lead people to have unrealistic expectations as they are normally not aware of FDA definitions of permanency. From the affected person s point of view permanency means that removed hair does not re-grow at all. Using this more readily understandable concept of permanency, no clinical trials to date have demonstrated permanent hair removal after laser or photoepilation. Those studies that have been performed indicate that such an effect is very unlikely since hair regrowth occurred in all studies that included this outcome measure. A U T H O R S C O N C L U S I O N S Pain, skin redness, swelling, burned hairs and pigmentary changes were infrequently reported adverse effects. Implications for research There is a need for high-quality trials of laser and photoepilation. Particularly needed are trials with long-term evaluations, trials evaluating the efficacy of lasers and IPL versus untreated control groups and trials comparing the efficacy of laser and IPL treatments. The importance of individual participant characteristics remains to be answered and trials are also required in specific populations such as hirsute women with and without endocrine dysfunction. Such trials could provide a more rational approach to the treatment strategy of unwanted hair growth and, hopefully, optimise the cost-benefits associated with the treatments and result in realistic expectations from affected people. Implications for practice Despite the enormous amount of resources involved in hair removal with lasers and intense pulsed light (IPL), there are no randomised trials that have shown a long-term effect of these interventions. There appeared to be a short-term effect of approximately 50% hair reduction with alexandrite and diode lasers up to six months after treatment, whereas little evidence was obtained for an effect of intense pulsed light, neodymium:yag or ruby lasers. Long-term hair removal was not obtained with any treatment. A C K N O W L E D G E M E N T S We thank the following authors who provided additional information on their trials: Alster TS, Clayton WJ, Fiskerstrand EJ, Goh CL, Lehrer MS, Ross EV. The editorial base would like to thank the following people who were external referees for this review: David de Berker, William Perkins (content experts) and Amy Zelmer (consumer). R E F E R E N C E S References to studies included in this review Allison 2003 {published data only} Allison KP, Kiernan MN, Waters RA, Clement RM. Evaluation of the ruby 694 Chromos for hair removal in various skin sites. Lasers Medical Science 2003;18(3): Clayton 2005 {published data only} Clayton WJ, Lipton M, Elford J, Rustin M, Sherr L. A randomized controlled trial of laser treatment among hirsute women with polycystic ovary syndrome. British Journal of Dermatology 2005;152(5): Eremia 2000 {published data only} Eremia S, Newman N. Topical anesthesia for laser hair removal: comparison of spot sizes and 755 nm versus 800 nm wavelengths. Dermatologic Surgery 2000;26(7): Fiskerstrand 2003 {published data only} Fiskerstrand EJ, Svaasand LO, Nelson JS. Hair removal with long pulsed diode lasers: a comparison between two systems with different pulse structures. Lasers in Surgery & Medicine 2003;32(5): Goh 2003 {published data only} Goh CL. Comparative study on a single treatment response to long pulse Nd:YAG lasers and intense pulse light therapy for hair removal on skin type IV to VI - Is longer wavelengths lasers preferred over shorter wavelengths lights for assisted hair removal. Journal of Dermatological Treatment 2003;14: Haedersdal 1999 {published and unpublished data} Haedersdal M, Egekvist H, Efsen J, Bjerring P. Skin pigmentation and texture changes after hair removal with the normal-mode ruby laser. Acta Dermato-Venereologica 1999;79(6): Handrick 2001 {published data only} Handrick C, Alster TS. Comparison of long-pulsed diode and long-pulsed alexandrite lasers for hair removal: a longterm clinical and histologic study. Dermatologic Surgery 2001;27(7): Hussain 2003 {published data only} Hussain M, Polnikorn N, Goldberg DJ. Laser-assisted hair removal in Asian skin: efficacy, complications, and the effect of single versus multiple treatments. Dermatologic Surgery 2003;29(3):

11 Lehrer 2003 {published data only} Lehrer MS, Crawford GH, Gelfand JM, Leyden JJ, Vittorio CC. Effect of wax epilation before hair removal with a longpulsed alexandrite laser: a pilot study. Dermatologic Surgery 2003;29(2): Nanni 1997 {published data only} Nanni CA, Alster TS. Optimizing treatment parameters for hair removal using a topical carbon-based solution and 1064-nm Q-switched neodymium:yag laser energy. Archives of Dermatology 1997;133(12): Nouri 2004 {published data only} Nouri K, Chen H, Saghari S, Ricotti CA, Jr. Comparing 18- versus 12-mm spot size in hair removal using a gentlease 755-nm alexandrite laser. Dermatologic Surgery 2004;30(4 Pt 1): References to studies excluded from this review Baugh 2001 {published data only} Baugh WP, Trafeli JP, Barnette DJ, Jr, Ross EV. Hair reduction using a scanning 800 nm diode laser. Dermatologic Surgery 2001;27(4): Baumler 2002 {published data only} Baumler W, Scherer K, Abels C, Neff S, Landthaler M, Szeimies RM. The effect of different spot sizes on the efficacy of hair removal using a long-pulsed diode laser. Dermatologic Surgery 2002;28(2): Bjerring 2000 {published data only} Bjerring P, Cramers M, Egekvist H, Christiansen K, Troilius A. Hair reduction using a new intense pulsed light irradiator and a normal ruby laser. Journal of Cutaneous Laser Therapy 2000;2: Boss 1999 {published data only} Boss WK, Usal H, Thompson RC, Fiorillo MA. A comparison of the long-pulse and short-pulse alexandrite laser hair removal systems. Annals of Plastic Surgery 1999; 42: Chan 2001 {published data only} Chan HH, Ying SY, Ho WS, Wong DS, Lam LK. An in vivo study comparing the efficacy and complications of diode laser and long-pulsed Nd:YAG laser in hair removal in Chinese patients. Dermatologic Surgery 2001;27(11): Elman 2000 {published data only} Elman M, Klein A, Slatkine M. Dark skin tissue reaction in laser assisted hair removal with a long-pulse ruby laser. Journal of Cutaneous Laser Surgery 2000;2(1): Eremia 2001 {published data only} Eremia S, Li C, Newman N. Laser hair removal with alexandrite versus diode laser using four treatment sessions: 1-year results. Dermatologic Surgery 2001;27(11): Fournier 2000 {published data only} Fournier N, Aghajan-Nouri N, Barneon G, Mordon S. Hair removal with an Athos Nd:YAG 3.5 ms pulse laser: a 3-month clinical study. Journal of Cutaneous Laser Therapy 2000;2(3): Freedman 2000 {published data only} Freedman BM, Earley RV. Comparing treatment outcomes between physician and nurse treated patients in laser hair removal. Journal of Cutaneous Laser Therapy 2000;2(3): Freedman 2000a {published data only} Freedman BM, Earley RV. A structured treatment protocol improves results with laser hair removal. Journal of Cutaneous Laser Therapy 2000;2(3): Goldberg 1999 {published data only} Goldberg DJ, Ahkami R. Evaluation comparing multiple treatments with a 2-msec and 10-msec alexandrite laser for hair removal. Lasers in Surgery & Medicine 1999;25: Goldberg 2001 {published data only} Goldberg DJ, Silapunt S. Hair removal using a long-pulsed Nd:YAG Laser: comparison at fluences of 50, 80, and 100 J/cm. Dermatologic Surgery 2001;27(5): Grossman 1996 {published data only} Grossman MC, Dierickx C, Farinelli W, Flotte T, Anderson RR. Damage to hair follicles by normal-mode ruby laser pulses. Journal of the American Academy of Dermatology 1996;35: Görgü 2000 {published data only} Görgü M, Aslan G, Aköz T, Erdogan B. Comparison of alexandrite laser and electrolysis for hair removal. Dermatologic Surgery 2000;26: Lorenz 2002 {published data only} Lorenz S, Brunnberg S, Landthaler M, Hohenleutner U. Hair removal with the long pulsed Nd:YAG laser: a prospective study with one year follow-up. Lasers in Surgery & Medicine 2002;30(2): Lou 2000 {published data only} Lou WW, Quintana AT, Geronemus RG, Grossman MC. Prospective study of hair reduction by diode laser (800 nm) with long-term follow-up. Dermatologic Surgery 2000;26: Nanni 1999 {published data only} Nanni CA, Alster TS. Long-pulsed alexandrite laser-assisted hair removal at 5, 10, and 20 millisecond pulse durations. Lasers in Surgery & Medicine 1999;24: Polderman 2000 {published data only} Polderman MCA, Pavel S, Le Cessie S, Grevelink JM, Van Leeuwen RL. Efficacy, tolerability, and safety of a longpulsed ruby laser system in the removal of unwanted hair. Dermatologic Surgery 2000;26: Rogachefsky 2002 {published data only} Rogachefsky AS, Silapunt S, Goldberg DJ. Evaluation of a new super-long-pulsed 810 nm diode laser for the removal of unwanted hair: the concept of thermal damage time. Dermatologic Surgery 2002;28(5): Rogachefsky 2002a {published data only} Rogachefsky AS, Becker K, Weiss G, Goldberg DJ. Evaluation of a long-pulsed Nd:YAG laser at different parameters: an analysis of both fluence and pulse duration. Dermatologic Surgery 2002;28(10):

12 Rogers 1999 {published data only} Rogers CJ, Glaser DA, Siegfried EC, Walsh PM. Hair removal using topical suspension-assisted Q-switched Nd: YAG and long-pulsed alexandrite lasers: A comparative study. Dermatologic Surgery 1999;25: Shidayama 2003 {published data only} Shidayama R. Side effects of using a diode laser (800 nm) for the removal of unwanted hair, a comparison of its two different pulse modes ( auto-mode versus 30ms-fixedmode ). Japanese Journal of Plastic Reconstructive Surgery 2003;46(7): Shidayama 2003a {published data only} Shidayama R. Long-term follow-up of hair reduction using a diode laser (800 nm) system: a comparison of two different pulse modes (auto-mode versus 30ms-fixed-mode). Japanese Journal of Plastic Reconstructive Surgery 2003;46(7): Sommer 1998 {published data only} Sommer S, Render C, Burd R, Sheehan-Dare RA. Ruby laser treatment for hirsutism: Clinical response and patient tolerance. British Journal of Dermatology 1998;138: Sommer 1999 {published data only} Sommer S, Render C, Sheehan-Dare RA. Facial hirsutism treated with the normal-mode ruby laser: Results of a 12- month follow-up study. Journal of the American Academy of Dermatology 1999;41: Walther 1998 {published data only} Walther T, Bäumler W, Wenig M, Landthaler M, Hohenleutner U. Selective photothermolysis of hair follicles by normal-mode ruby laser treatment. Acta Dermato- Venereologica (Stockholm) 1998;78: Weiss 1999 {published data only} Weiss RA, Weiss MA, Marwaha S, Harrington AC. Hair removal with a non-coherent filtered flashlamp intense pulsed light source. Lasers in Surgery & Medicine 1999;24: Additional references Alster 2001 Alster TS, Bryan H, Williams CM. Long-pulsed Neodymium:YAG laser-assisted hair removal in pigmented skin. Archives of Dermatology 2001;137: Altshuler 2001 Altshuler GB, Anderson RR, Manstein D, Zenzie HH, Smirnov MZ. Extended theory of selective photothermolysis. Lasers in Surgery & Medicine 2001;29: Anderson 1983 Anderson RR, Parrish JA. Selective photothermolysis: Precise microsurgery by selective absorption of pulsed radiation. Science 1983;220: Dierickx 2002 Dierickx C. Hair removal by lasers and intense pulsed light sources. Dermatologic Clinics 2002;20: Goldberg 2002 Goldberg DJ. Laser hair removal. Dermatologic Clinics 2002;20: Higgins 2005 Higgins JPT, Green S, editors. Cochrane Handbook for Systematic Reviews of Interventions [updated May 2005]. The Cochrane Library 2005, Issue 3. Hædersdal 1999 Hædersdal M, Egekvist H, Efsen J, Bjerring P. Skin pigmentation and texture changes after hair removal with the normal-mode ruby laser. Acta Dermato-Venereologica 1999;79: Hædersdal 2006 Hædersdal M, Wulf HC. Evidence based review of hair removal using lasers and light sources. Journal of the European Academy of Dermatology & Venereology 2006;20 (1):9 20. Liew 1999 Liew SH. Unwanted body hair and its removal: A review. Dermatologic Surgery 1999;25: Liew 2002 Liew SH. Laser hair removal: guidelines for management. American Journal of Clinical Dermatology 2002;3: Olsen 1999 Olsen EA. Methods of hair removal. Journal of the American Academy of Dermatology 1999;40: Sanchez 2002 Sanchez LA, Perez M, Azziz R. Laser hair reduction in the hirsute patient: a critical assessment. Human Reproduction Update 2002;8(2): Schulz 1995 Schulz KF, Chalmers I, Hayes RJ, Altman DG. Empirical evidence of bias. Dimensions of methodological quality associated with estimates of treatment effects in controlled trials. JAMA 1995;273(5): Indicates the major publication for the study 10

13 C H A R A C T E R I S T I C S O F S T U D I E S Characteristics of included studies [ordered by study ID] Allison 2003 Methods Participants Interventions Outcomes Notes Within-participant trial. Randomisation: coin tossing. No blinding. n = 69 (68 females). Data from up to half of the participants missing. Upper lip, axilla, leg. Skin types I to III. Hair colour NA. T1: Ruby laser 2 Txs. T2: Ruby laser 3 Txs. Hair counts up to five months after final Tx. Physical parameters: Ruby laser 694 nm, 0.9 ms pulse duration, 7 mm spot, fluences 10 to 14 J/cm2. Inadequate randomisation that produced substantial skewness. Risk of bias Item Authors judgement Description Allocation concealment? No C - Inadequate Clayton 2005 Methods Participants Interventions Outcomes Notes Parallel group trial. Randomisation: open table of random numbers. Participants, psychologist and data entry clerk blinded n = 88. Losses 13. Females with hirsutism due to polycystic ovary syndrome. Face. Skin types I to V. Dark hair T1: alexandrite laser with high fluences. T2: alexandrite laser with low fluence (sham) Self-reported severity of facial hair and time spent on hair-removal. Depression. Anxiety. Quality of life Physical parameters: Alexandrite laser 755 nm, 20 ms pulse duration, 12.5 mm spot, fluences T1: 14 to 30 J/cm2 (mean 23.6 J/cm2), T2: 4.8 J/cm2. Risk of bias Item Authors judgement Description 11

14 Clayton 2005 (Continued) Allocation concealment? No C - Inadequate Eremia 2000 Methods Participants Interventions Outcomes Within-participantstudy. Randomisation: randomly alternated. No blinding. n = 12. Losses NA. Females. Axilla. Skin types I to IV. Hair colour NA. T1: Alex laser 8 mm spot +/- topical anesthesia vs T2: Similar but 12 mm spot T3: Similar but max fluence T4: Diode laser max fluence, 9 mm spot +/- topical anesthesia Pain Notes Physical parameters: Alexandrite laser 755 nm, 3 ms pulse duration, 8 to 12 mm spot, max fluence 40 J/ cm2. Diode laser 800 nm, 20 ms pulse duration, 9 mm spot, max fluence 40 J/cm2 Risk of bias Item Authors judgement Description Allocation concealment? No C - Inadequate Fiskerstrand 2003 Methods Participants Interventions Outcomes Notes Within-participant study. Randomisation procedure: Alternation. Blind (photo). n = 41. Losses 12. Females. Upper lip. Skin types II to IV. Brown, black hairs T1: Diode laser 810 nm, 3 Txs T2: Diode laser 800 nm, 3 Txs. Hair counts six months after final Tx. Adverse effects. Physical parameters: Mediostar diode laser, 12 mm spot, 45 ms pulses x 2, 35 J/cm2. LightSheer diode laser 800 nm, 9x9 mm spot, 30 ms pulse duration, 35 J/cm 2. Risk of bias 12

15 Fiskerstrand 2003 (Continued) Item Authors judgement Description Allocation concealment? No C - Inadequate Goh 2003 Methods Participants Interventions Outcomes Notes Within-participant study. Randomisation procedure: Drawing one of two lots from open envelope. No blinding. n = 11. No losses. Females. Face, axilla, legs. Skin types IV to VI. Black hairs T1: Nd:YAG laser 1 Tx + topical anaesthetic. T2: Intense pulsed light 1 Tx + topical anaesthetic. Self-reported subjective reduction in hairiness 6 weeks after Tx. Pain, blistering and pigmentation 0 to 2 weeks after Tx. Physical parameters: Nd:YAG laser 1064 nm, 10 mm spot, 20 to 25 ms pulse duration, 35 to 42 J/cm2. Intense pulsed light 600 to 950 nm, 5 to 40 ms pulse, 12 to 14 J/cm2 Risk of bias Item Authors judgement Description Allocation concealment? No C - Inadequate Haedersdal 1999 Methods Participants Within-participantstudy. Randomisation procedure: open table of random numbers. Blinded observer (on-site). n = 17 (9 females). No losses. Pubic region. Skin types I to IV. Red, blonde, brown, black hairs Interventions T1: Ruby laser 1 Tx, 15 J/cm 2 T2: Ruby laser 1 Tx, 20 J/cm 2 T3: Ruby laser 1 Tx, 25 J/cm 2 versus T4: Untreated control area Outcomes Adverse effects 12 weeks after Tx. Notes Physical parameters: Ruby laser 694 nm, 0.8 ms pulse duration, 5 mm spot, fluences 15 to 25 J/cm 2. Risk of bias 13

16 Haedersdal 1999 (Continued) Item Authors judgement Description Allocation concealment? No C - Inadequate Handrick 2001 Methods Participants Within-participant study. Randomisation: Card draw. Blinded assessors (on-site) and blinded photos. n = 20. No losses. Females. Axilla. Skin types I - IV. Brown to black hairs Interventions T1: alexandrite laser 3 Tx (25 J/cm 2 ). T2: diode laser 3 Tx (25 J/cm 2 ). T3: diode laser 3 Tx (40 J/cm 2 ). Outcomes Hair counts 1, 3, 6 months after final Tx. Clinical improvement scores. Pain. Adverse effects up to 6 months after final Tx Notes Physical parameters: Alexandrite laser 755 nm, 2 ms pulse duration, 10 mm spot, 25 J/cm 2. Diode laser 800 nm, 12.5 and 20 ms pulse durations, 9 mm spot, 25 and 40 j/cm 2. Risk of bias Item Authors judgement Description Allocation concealment? No C - Inadequate Hussain 2003 Methods Participants Interventions Outcomes Parallel group study. Randomisation: unclear. Blinded (photos). n = 144 (136 females). Losses NA. Axilla, arms, legs. Asian participants with skin types III to V. Hair colour NA T1: alexandrite laser 1 Tx. T2: alexandrite laser 2 Tx. T3: alexandrite laser 3 Tx. Hair counts nine months after final Tx. Adverse effects up to nine months after final Tx Notes Physical parameters: alexandrite laser 755 nm, 40 ms pulse duration, 12.5 mm spot, 16 to 24 J/cm 2. Many participants were treated in more than one region. Risk of bias 14

17 Hussain 2003 (Continued) Item Authors judgement Description Allocation concealment? Unclear B - Unclear Lehrer 2003 Methods Participants Interventions Outcomes Notes Within-participant study. Randomisation: coin tossing. Blinded (photo). n = 13. No losses. Males. Back. Skin types I to III. Brown, black hairs T1: wax + alexandrite laser. T2: alexandrite laser. T3: wax. T4: untreated control. Hairiness one month after tx. Physical parameters: Alexandrite laser 755 nm, 10 to 27 ms pulse durations, 12 mm spot, 15 to 19 J/cm 2. Risk of bias Item Authors judgement Description Allocation concealment? No C - Inadequate Nanni 1997 Methods Participants Interventions Outcomes Within-participant study. Randomisation: card draw determined first Tx, the others applied in clockwise order. Blinded (photo). n = 12 (9 females). No losses. Back, upper lip, chin, leg. Skin types I to IV. Brown, black hairs T1: wax + carbon solution + Q-switched Nd:YAG laser 1 Tx. T2: wax + Q-switched Nd:YAG laser 1 Tx. T3: wax 1 Tx. T4: Q-switched Nd:YAG laser 1 Tx. Hair counts one, three, six months after Tx. Self-reported subjective reduction in hairiness one, three, six months after Tx Notes Physical parameters: Q-switched Neodymium:YAG laser 1064 nm, 50 ns pulse duration, 7 mm spot, 2. 6 J/cm2. Six participants were treated in two regions 15

18 Nanni 1997 (Continued) Risk of bias Item Authors judgement Description Allocation concealment? No C - Inadequate Nouri 2004 Methods Participants Interventions Outcomes Notes Within-participant study. Randomisation: Unclear. Blinding (photo). n = 17 (females). Losses 6. Axilla. Skin types II to IV. Hair colour NA T1: alexandrite laser 18 mm spot, 3 Tx. T2: alexandrite laser 12 mm spot, 3 Tx. T3: untreated control. Hair counts six months after last Tx. Physical parameters: Alexandrite laser 755 nm, 3 ms pulse duration, 16 J/cm 2, preop. Risk of bias Item Authors judgement Description Allocation concealment? Unclear B - Unclear Blinding refers to outcome assessment only, n = number, NA = not available, Tx(s) = treatment(s), T1, etc = treatment number. Characteristics of excluded studies [ordered by study ID] Study Baugh 2001 Baumler 2002 Bjerring 2000 Boss 1999 Chan 2001 Reason for exclusion 16

19 (Continued) Elman 2000 Eremia 2001 Fournier 2000 Freedman 2000 Freedman 2000a Goldberg 1999 Goldberg 2001 Grossman 1996 Görgü 2000 Lorenz 2002 Lou 2000 Nanni 1999 Polderman 2000 Rogachefsky 2002 Rogachefsky 2002a Rogers 1999 Shidayama 2003 Shidayama 2003a Sommer 1998 Retrospective trial. Retrospective trial. Sommer 1999 Same study as Sommer Walther 1998 Weiss 1999 Uncontrolled study. 17

20 D A T A A N D A N A L Y S E S This review has no analyses. A P P E N D I C E S Appendix 1. Search strategy for the Cochrane Skin Group s Specialised Register ((hair* and follicle) or (hair* and remov*) or (hair* and excess*) or hirsut* or hypertricho* or hyperandrogen* or Title = hair) AND ((light and energy) or (pulsed and light) or (light and coagulation) or photoepilation or laser* or (photo* and therap*)) AND NOT (alopecia or acne). Appendix 2. Search strategy for Medline (Silver Platter) (i) Search strategy to locate RCTs Search terms 1-36, as given in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2005), appendix 5c.1 (ii) Search strategy to locate unwanted hair growth 37. hirsutism in MeSH 38. hypertrichosis in MeSH 39. hyperandrogenism in MeSH 40. hair-follicle in MeSH 41. hair-removal in MeSH 42. (hair in ti) or (hair in ab) 43. (hirsutism in ti) or (hirsutism in ab) 44. (hypertrichosis in ti) or (hypertrichosis in ab) 45. (hyperandrogenism in ti) or (hyperandrogenism in ab) 46. hair adj removal 47. #37 or #38 or #39 or #40 or #41 or #42 or #43 or #44 or #45 or #46 (iii) Search strategy to locate specific treatments for hair removal 48. explode light in MeSH 49. explode laser-surgery in MeSH 50. explode light coagulation in MeSH 51. (laser* in ti) or (laser* in ab) 52. (light* in ti) or (light* in ab) 53. #48 or #49 or #50 or #51 or #52 (iv) Combining searches (i) - (iii) 54. #47 and # # 36 and #54 18