STUDY Long-term Photoepilation Using a Broad-spectrum Intense Pulsed Source

Neil S. Sadick, MD; Robert A. Weiss, MD; Christopher R. Shea, MD; Hila Nagel; Judith Nicholson, RN; Victor G. Prieto, MD, PhD

Background: The goal of laser or flashlamp photoepi- Main Outcome Measures: removal efficiency, lation is to produce long-term, cosmetically significant calculated as percentage ratio of the number of . We document the long-term efficacy present compared with baseline counts, and patient sat- achieved with an intense pulsed light source for photo- isfaction questionnaire completed at last follow-up. epilation. Results: The mean hair removal efficiency achieved was Design: Prospective study comparing long-term re- 76% after a mean of 3.7 treatments. More than 94% of sults of single vs multiple treatments, and effects of ana- the sites reached mean hair removal efficiency values tomic site and type on efficacy of photoepilation with greater than 50%. Hair removal efficiency was not sig- a device emitting broad-spectrum, noncoherent (nonla- nificantly related to skin type, hair color, anatomic site, ser) radiation from 550- to 1200-nm wavelengths, in mac- or number of treatments. Side effects were mild and re- ropulses divided into 2 to 5 minipulses. versible and occurred in a minority of patients (hyper- pigmentation in 3 and superficial crusting in 2). Setting: Private practice. Conclusions: Our data document the long-term clini- Patients: Thirty-four patients (8 men, 26 women) with cal efficacy of intense pulsed light source–induced hair hirsutism. removal in light and dark skin phenotypes. Maximal pho- toepilation was achieved from the initial 1 to 3 treat- Interventions: Parameters for the study were wave- ments; only a small added benefit was seen after more length of 615 to 695 nm, pulse duration of 2.6 to 3.3 mil- treatments. liseconds, fluence of 34 to 42 J/cm2,10ϫ45-mm expo- sure field, and application of 1°C cooling gel. Arch Dermatol. 2000;136:1336-1340

HE GOAL of laser or flash- zation in efficacy of photoepilation.3,5 lamp photoepilation is to Multiple treatments may increase mela- From the Department of produce long-term, or per- nocyte synthetic activity, which may pro- Dermatology, Weill Medical manent, cosmetically sig- duce more beneficial results.2,3 Hair color, College of Cornell University, nificant hair removal. The pilosebaceous depth, and New York, NY (Dr Sadick); the major proposed mechanism of action is thickness also may influence photoepila- Department of Dermatology, T 1 1,2,3,6 “selective photothermolysis,” with fol- tion efficiency ; specifically, white to Johns Hopkins School of licular as the major target chro- blond hairs, deeper pilosebaceous depth, Medicine, Baltimore, Md (Dr Weiss); the Departments of mophore. Wavelengths in the red and and thicker diameter of hair follicles are Pathology and Medicine infrared range (600-1100 nm) of the elec- associated with decreased photoepilation 3,6 (Dermatology), Duke tromagnetic spectrum are optimal for this efficiency. University Medical Center, goal.2 Melanization of the hair follicle has Another mechanism proposed to be Durham, NC (Dr Shea); ESC been shown to be maximal during the important in photoepilation is “thermoki- Sharplan, Yokneam, Israel anagen phase.3,4 It has been proposed that netic selectivity,” whereby target struc- (Ms Nagel) and Norwood, Mass efficiency of photoepilation may be opti- tures of large volume such as hair shafts are (Ms Nicholson); and the mal during this phase; since the length of unable to transmit absorbed energy to sur- Departments of Pathology and the hair cycle varies among different ana- rounding structures, compared with smaller Medicine (Dermatology), tomic regions, equipment settings may volume structures containing the same University of Texas–MD 6,7 Anderson Cancer Center, need to be modified accordingly to take . By selecting the appropri- Houston (Dr Prieto). Ms Nagel advantage of phase-dependent melaniza- ate pulse length, the thermal damage may is an employee of ESC Medical tion. However, recent studies have ques- be concentrated in the target structures (fol- Systems. tioned the primary role of anagen melani- licular papilla, germinative cell layer, and

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2 STUDY GROUPS A 1-cm grid was used to count hairs at baseline and at vari- ous subsequent times (including 1, 2, 3, 4, 6, 8, 9, 12, 14, The study group consisted of 8 men and 26 women with ex- 16, 18, 20, 24, and 30 months after IPL treatment for dif- cess , aged 16 to 68 years (mean, 38 years), who ferent patients) as previously described.27 The data summa- entered a multiple-treatment protocol and had long-term fol- rize the final clearance results observed at the last fol- low-up of 12 to 30 months since their first treatment. The low-up visit, accounting for different follow-up intervals after 34 patients each had 1 anatomic site studied by 1 of 2 inves- initial treatment (range, 12-30 months; mean±SD, 21.1±5.1 tigators (N.S.S. and R.A.W.), and were enrolled between April months). The treatment sites were localized with respect to 1997 and September 1999. Fitzpatrick skin types ranged from defined anatomic landmarks (umbilicus, iliac crest, nipple, II to V, and all patients had black or brown in mandibular ramus, chin, or acromion), confirmed by refer- the areas selected for treatment. Previous modalities used on ence to standardized photographs (Yashica Medical Eye II the test sites before flashlamp irradiation included (14 [Tokyo, Japan] with macrolens, shooting area of 24ϫ360 patients), chemical depilatories (20 patients), and (16 mm, shooting distance of 15.5 cm, and consistent lighting patients). Any such treatments were discontinued at least 4 and patient positioning). The hairs were counted with the weeks before IPL irradiation. Patients avoided UV-B expo- aid of a hand lens by either of 2 investigators (N.S.S. and sure for 4 weeks before and after each treatment session. R.A.W.) in a nonblinded manner. The hair removal effi- Of the 34 total patients, a subgroup of 14 patients was ciency (HRE) was calculated as a percentage of the number available for evaluation 12 months or more after their fi- of hairs present compared with baseline counts. Results were nal treatment. This subgroup was enrolled between April tabulated semiquantitively as “excellent” (HRE of 76%- 1997 and August 1998, and received multiple treatments 100%), “good” (51%-75%), “fair” (26%-50%), or “poor” to a total of 14 anatomic sites. (0%-25%). Side effects, if any, were recorded at each visit. For analysis, data were stratified according to the following PHOTOEPILATION PROTOCOL subsets: (1) light vs dark skin phenotypes (Fitzpatrick skin types I-III vs IV-V), (2) hair color (light-to-medium brown Immediately before IPL treatment, hairs were trimmed to 1 vs dark brown vs black), (3) anatomic location (torso vs ex- mm and a 1°C cooling gel transparent to the irradiation wave- tremities vs face), and (4) number of treatments (1-3 vs 4-7). lengths was applied to the surface. The IPL treatment was ad- At the end of treatment, a questionnaire was administered ministered with surface exposure parameters related to Fitz- to determine the level of patient satisfaction: not satisfied, patrick skin type (Table 1), to a 10ϫ45-mm exposure field. slightly satisfied, moderately satisfied, and greatly satisfied. All patients received 3 monthly treatments, and 13 had subsequent treatments as necessitated for further clinical STATISTICAL ANALYSIS improvement and/or because of partial regrowth of hair. Further treatments were administered at intervals of 1 month The ␹2 and the paired t tests were used to compare groups. or more. PϽ.05 was considered significant.

bulge area).8 This is achieved by setting the duration of the impulse above the calculated thermal relaxation time Table 1. Photoepilation Protocol for Long-term Study of the epidermis (3-10 milliseconds) and below the ther- Fitzpatrick Filter, nm Fluence, Pulse No. of Pulse mal relaxation time of the hair follicles (40-100 Skin Type (Long-Pass) J/cm2 Duration, ms Pulses Delay, ms milliseconds).9 Both selective photothermolysis and ther- mokinetic selectivity are hypothesized to mediate photo- II 615 39-42 3.3 2 30 10-16 17-19 20 III 645 34-36 3.0 3 30 epilation via ruby, alexandrite, diode, and Q- IV 645 34-40 3.0 3 40 21-25 switched Nd:YAG lasers, as well as intense pulsed light V 695 38-40 2.6 3 30 (IPL) source26-32 technologies. The present report documents the long-term effi- cacy and permanent results achieved with an IPL source In a previous study27 on 58 subjects, we reported mean for photoepilation (EpiLight; ESC Medical Systems, Nor- at follow-up ranges of less than 3 months, 3 to 6 wood, Mass/Yokheam, Israel). This device emits broad- months, and 6 months or longer of 49%, 57%, and 54%, spectrum, noncoherent (nonlaser) radiation from 550- respectively, with a single treatment, and 74%, 56%, and to 1200-nm wavelengths. Unique to this technology is 64%, respectively, with multiple treatments (wave- modulation of a pulse into a series of 2 to 5 minipulses, length, 590-695 nm; pulse duration, 2.9-3.0 millisec- the duration and delay of which are customizable within onds; fluence, 40-42 J/cm2). Herein we report on a series the millisecond range. A footprint spot size of 10ϫ45 of 34 patients with long-term follow-up, of whom 8 were mm or 8ϫ35 mm is available. Theoretically, these op- previously described with a shorter follow-up interval.27 tions should allow deep penetration of radiation with a uniform beam, targeting deeper follicles as well as coarse RESULTS or thin hair, while achieving “epidermal bypass” to mini- mize dyschromia. According to the specifications pro- Thirty-four anatomic sites in 34 patients were treated. vided by the manufacturer, almost all skin types can be The mean HRE achieved was 76% after a mean of 3.7 treat- treated using these parameters. ments (33%-100%, SD). The differences in hair count

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©2000 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/25/2021 (pretreatment vs at final follow-up) were highly signifi- Although patients with skin types I to III experi- cant (PϽ10 −10)(Figure 1). enced a slightly higher HRE than types IV to V (76% vs Temporary (“footprinting”) oc- 73%), this difference was not statistically significant. More- curred in 3 patients (9%) and resolved within 12 weeks over, hair color was not a significant variable affecting in all treated individuals. Superficial crusting occurred HRE (dark brown hair, 82%; black hair, 68%; light-to- in 2 patients (6%) and resolved without scarring in 2 medium brown hair, 70%). Finally, HRE was not signifi- weeks or less. The incidence of side effects did not vary cantly related to number of treatments (1-3 treatment significantly as a function of skin type. mean HRE, 75%; 4-7 treatment mean HRE, 77%). A majority of treated sites (21 of 34 sites, 62%) ex- In the subgroup of 14 patients followed up for more hibited excellent HRE and 11 sites had good results; thus, than 12 months (mean, 20 months) after the last treat- 94% of the sites reached mean HRE values above 50%. ment (Table 2), a final HRE of 83% was achieved after Only 2 patients had fair results and none had poor out- a mean of 3.9 treatments, slightly better than the overall come (Figure 2). Anatomic site was not a significant group results (Figure 3). variable determining HRE (torso mean HRE, 78%; To determine any possible difference regarding short- mean HRE, 72%). term or long-term follow-up HRE, percentages were com- bined into 6 separate groups with cutoff times at 5, 10, 15, 20, 25, and 30 months of follow-up. Mean HRE val- 100 Mean Clearance = 76% ues continued to improve after the last treatment, with 80 a final HRE of 92%±12% at 30 months’ follow-up. Figure 4 demonstrates a representative patient with ex- 60 cellent results at long-term follow-up.

HRE, % 40 Of the 29 individuals who completed the satisfaction 20 questionnaire at the last follow-up, only 3 (10%) were not satisfied at all. Twenty-four (83%) were moderately to 0 5 10 15 20 25 30 greatly satisfied; of these, 15 (52%) were greatly satisfied. Months Since First Treatment

Figure 1. Final clearance as a function of time in 34 patients receiving COMMENT multiple treatments. HRE indicates hair removal efficiency. Four clinical responses may ensue after the light exposure (Table 3). First, heat-induced destruction of the hair shaft 80 without germinative area damage may lead to hair “drop- 62% (21) out,” ie, the hair shaft falls out and then regrows at the next 60 scheduled anagen cycle as a nonaffected, terminal hair. Sec- ond, besides the hair shaft, there may be partial injury to 40 32% the germinative (amplification) zone of the hair follicle, re- (11) sulting in trichoregulatory dysfunction, telogen-shock Mean HRE, % response, prolonged telogen dropout, and eventual re- 20 6% growth of normal hair once the anagen phase has been re- 0% (2) (0) instituted. Third, partial germinative zone injury may lead 0 0-25 26-50 51-75 76-100 to the development of dystrophic hairs (thinner and finer % Clearance in texture, with variable hypopigmentation). Finally, long- Figure 2. Distribution of clearance values obtained at final follow-up visit term photoepilation may ensue, defined as a reduction in (number of sites). HRE indicates hair removal efficiency. the number of hairs over an interval longer than the nor-

Table 2. Long-term Follow-up Subgroup (Follow-up Ͼ12 Months After Last Treatment)

No. of Last Months Since Months Since Final Hair Hair Removal Patient No. Location Treatments Follow-up Date Initial Treatment Last Treatment Count Efficiency, % 1 Chest 5 12/14/98 19 15 1 89 2 Abdomen 3 12/98 15 13 3 79 3 Chest 4 6/99 24 15 1 91 4 Lip 3 2/99 20 18 4 56 5 Mandible 3 11/98 15 13 8 69 6 Back 3 4/28/99 20 18 2 78 7 Bikini 3 6/99 14 12 1.5 75 8 Bikini 3 10/99 24 22 1.5 70 9 Bikini 6 9/16/99 20 14 0.5 98 10 Abdomen 5 4/25/99 21 15 1 96 11 Chin 6 6/23/99 26 16 0 100 12 Lip 3 9/99 29 26 2.5 83 13 Face 2 9/99 13 12 1 94 14 Face 5 9/99 21 15 2.5 86

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©2000 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/25/2021 mal hair cycle (usually 1-3 months depending on the par- a single treatment in patients with skin types IV and V, ticular given anatomic region). Long-term (or potentially respectively, examined over 15 months; patients with skin permanent) photoepilation most likely is a consequence types IV and V were treated with a 645- and 695-nm cut- of light-induced interactions with the primary “bulge” and off filter, respectively, with average fluence of 37 J/cm2, secondary matrix germinative regions of the piloseba- 3 to 4 minipulses, a pulse duration of 2.8 to 2.9 milli- ceous unit.6 To induce permanent hair removal, “pan- seconds, and 57- to 60-millisecond delay between pulses. tricho” destruction of the entire germinative areas of the Gold et al29 performed a single-exposure study with an hair follicle (bulge/trichoepithelium/matrix) must occur. IPL system. After 12 weeks, a 60% HRE was noted. Flu- Permanent, nonscarring hair loss has been described fol- ences ranged from 34 to 55 J/cm2. Another study30 re- lowing a single treatment with high-fluence ruby laser ported a 75% HRE 12 months after a single treatment in pulses,7 similar to that seen with flashlamp devices.27 Min- 24 patients with skin types I to VI and light brown to black iaturization of the terminal hair follicles seems to account hair; no specific treatment parameters were mentioned. for this response.7 In a multicenter study,21 40 women with hirsutism of the Results of this study using an IPL source for pho- upper lip and chin achieved a 76.7% HRE after an aver- toepilation confirm that partial, long-term hair removal age of 6 treatments; the average fluence was 38.7 J/cm2 may be achieved. Successful hair removal with the Epi- and mean wavelength was 585 nm. Schroeter et al31 re- Light has previously been reported at shorter follow-up ported on 40 women with a median age 38.6 years, hav- periods. A preliminary study by Weir and Woo28 dem- ing hirsutism of the upper lip and chin. The HRE was onstrated 42% and 37% reduction of hair density using 76.7% within 6 treatments, with an average fluence of 38.7 J/cm2 and a mean wavelength of 585 nm. Weiss et 32 Mean Clearance = 83% al treated 23 patients with an IPL source with a double- 100 90 treatment protocol (cutoff filter of 615-645 nm based on 80 Fitzpatrick skin type, pulse duration of 2.8-3.2 millisec- 2 70 onds, 3 pulses, and fluence of 40-42 J/cm ), and showed 60 an HRE of 42% at 8 weeks and 33% at 6 months. Pre- 50 liminary data have also been reported with a second- 40 33

% Clearance generation, broad-spectrum IPL source. Ten female pa- 30 tients with dark hair at the groin and of skin types II to 20 IV were treated (600 nm) 4 times with a 1-month inter- 10 0 val. An HRE of 74.7% at 4 and 8 months after the last 05 10 15 20 25 30 treatment were 74.7% and 80.2%, respectively. Months Since First Treatment In the present study, a mean HRE of 76% was achieved after a mean of 3.7 treatment sessions, in pa- Figure 3. Percent clearance as a function of time in 14 patients receiving multiple treatments and long-term follow-up (Ͼ12 months since the last tients followed up for a mean of 21.1 months. The long treatment). wavelengths, ability to partition high-energy fluences, and

A B

Figure 4. Patient 3. Pretreatment (A) and posttreatment (B) results. Hair removal efficiency at 24 months’ follow-up was 91% (skin type II, chest, 4 treatments, 615-nm filter, fluence of 40 J/cm 2, pulse duration of 3.3 milliseconds, 2 pulses, pulse delay of 30 milliseconds).

Table 3. Potential Effects of Light-Pilosebaceous Interactions

Target Effect Result Growth Delay Hair Appearance Hair shaft Hair shedding − Normal terminal hair Trichoregulation Telogen shedding + Normal, with anagen regrowth Partial germinative zonal disruption Dystrophic hair regrowth +/− Tapered/hypopigmented hair Total germinative zone ablation Permanent alopecia Not applicable No regrowth

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©2000 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/25/2021 long pulse durations available with this technology may ruby laser light on ex vivo hair follicles: clinical implications. Ann Plast Surg. 1999; explain the similarity of our results to those described 42:249-254. 10 6. Sadick NS. Laser and flashlamp photoepilation: a critical review of modern con- with the long-pulsed ruby laser. cepts bridging basic science and clinical application. J Aesthet Derm Cosmet Surg. It is somewhat surprising that we demonstrated equal 1999;1:95-101. photoepilation efficiency in light-to-medium brown and 7. Dierickx C, Alora MB, Dover JS. A clinical overview of hair removal using lasers black hair. A likely explanation is that the amount of en- and light sources. Dermatol Clin. 1999;17:357-366. ergy delivered is sufficient to damage the hair in either sub- 8. Tope WD, Hordinsky MK. A hair’s breadth closer [editorial]? Arch Dermatol. 1998; 134:867-869. type long-term. The similar HRE in treatments involving 9. Lask G, Eckhouse S, Slatkine M, Waldman A, Kreindel M, Gottfried V. The role of the face and torso is also unexpected, but should be inter- laser and intense light sources in photoepilation: a comparative evaluation. J Cu- preted with caution in view of the relatively small number tan Laser Ther. 1999;1:3-13. of patients examined in this long-term study. Anagen turn- 10. Dierickx C, Grossman MC, Farinelli WA, Anderson RR. Permanent hair removal over is increased in the scalp and face regions, compared by normal mode ruby laser. Arch Dermatol. 1998;134:837-842. 11. Lin TXD, Mianuskiatt W, Dierickx C, et al. Hair growth cycle affects hair follicle with the torso and extremities, and might have been ex- destruction by ruby laser pulses. J Invest Dermatol. 1998;111:107-113. pected to favor a greater photoepilation efficiency on the 12. Sommer S, Rendes C, Sheehan-Dare R. Facial hirsutism treated with the normal former sites.34 Further studies are necessary to substanti- mode ruby laser: results of a 12 month follow-up study. J Am Acad Dermatol. ate body site–dependent clinical photoepilation effi- 1999;41:974-979. ciency, related to relative anagen duration and piloseba- 13. Lask G, Elman M, Statkine M, Waldman A, Rosenberg Z. Laser assisted hair re- moval by selective photothermolysis preliminary results. Dermatol Surg. 1997; ceous depth and average hair shaft diameter. 23:737-739. Patients in this study had the greatest HRE after 1 to 14. Williams R, Havoo N, Jian H, Isaghollan K, Menaker G, Moy R. A clinical study of 3 treatments. Although further treatments led to some in- hair removal using the long pulsed ruby laser. Dermatol Surg. 1998;24:837-842. creased hair removal, the added benefit was small. Possi- 15. Grossman M, Dierickx C, Farinelli W, Flotte T, Anderson RR. Damage to hair fol- bly, the initial flashlamp treatment has sufficient energy to licles by normal mode ruby laser pulses. J Am Acad Dermatol. 1996;35:889-894. 16. Liew SH, Grabbelaas A, Gault D, Sander PR, Green C, Linger C. Hair removal destroy the largest number of anagen follicles during the using the ruby laser: clinical efficacy in Fitzpatrick skin types I-V and histologic initial treatment session. Light-induced regression of fol- changes in epidermal melanocytes. Br J Dermatol. 1999;140:1105-1109. licles into the catagen or telogen phase may make these tar- 17. Nanni CA, Alster TS. Long pulsed alexandrite laser assisted hair removal at 5, gets less susceptible to subsequent treatments.2,7 10, 20 milliseconds and pulse durations. Laser Surg Med. 1999;24:332-337. All treated sites in this study achieved greater than 18. McDaniel DH, Lord J, Ash K, Newman J, Zukowski M. : a review and report on the use of the long pulsed alexandrite laser for hair removal reduc- 50% HRE when evaluated more than 12 months follow- tion of the upper lip, leg, back and bikini region. Dermatol Surg. 1999;25:425-430. ing the last treatment; this finding correlated with the ob- 19. Goldberg DJ, Ahkami R. Evaluation comparing multiple treatments with a 2 msec served high level of patient satisfaction. It is unlikely that and 10 msec alexandrite laser for hair removal. Lasers Surg Med. 1999;25:223- any miniaturized or damaged hairs could regrow after such 228. 20. Williams RM, Gladstone HB, Moy RL. Hair removal using an 810 nm gallium alu- a long period. The observed increasing improvement of minum arsenide semiconductor diode laser: a preliminary study. Dermatol Surg. HRE following the last treatment may be related to par- 1999;25:935-937. tial pilosebaceous injury with subsequent long-term 21. Rogers CJ, Glaser DA, Siegfried EC, Walsh PM. Hair removal using topical sus- “dropout” effect. pension assisted Q-switched Nd:YAG and lag pulsed alexandrite lasers: a com- In conclusion, our data document the long-term parative study. Dermatol Surg. 1999;25:844-850. 22. Nanni CA, Alster TA. A practical review of laser assisted hair removal using the clinical efficacy of IPL-induced hair removal in light and Q-switched Nd:YAG long pulsed ruby and long pulsed alexandrite lasers. Der- dark skin and hair phenotypes. Maximal HRE was matol Surg. 1998;24:1399-1403. achieved from the initial treatments. The documenta- 23. Goldberg DJ, Littler CM, Wheeland RG. Topical suspension assisted Q-switched tion of maintenance of diminished hair counts for up to Nd:YAG laser hair removal. Dermatol Surg. 1997;23:741-745. 30 months after last treatment supports the long-term 24. Nanni CA, Alster TA. Optimizing treatment parameters for hair removal using a topical carbon based solution and 1064 nm Q-switched neodymium:YAG laser value of IPL technology in the treatment of hirsutism. energy. Arch Dermatol. 1997;133:1546-1549. 25. Littler CM. Hair removal using an Nd:YAG laser system. Dermatol Clin. 1999;17: Accepted for publication June 30, 2000. 401-430. 26. Tse V. Hair removal using a pulsed-intense light source. Dermatol Clin. 1999; This study was supported in part by ESC Sharplan, Nor- 17:373-380. wood, Mass. 27. Sadick NS, Shea CR, Burchette JL, Prieto VG. High-intensity flashlamp photo- Reprints: Neil S. Sadick, MD, 772 Park Ave, New York, epilation: a clinical, histologic and mechanistic study in human skin. Arch Der- NY 10021 (e-mail: [email protected]). matol. 1999;135:666-676. 28. Weir VM, Woo TY. Photo-assisted epilation: review and personal observations. J Cutan Laser Ther. 1999;1:135-143. REFERENCES 29. Gold MH, Bell MW, Foster TD, Street S. 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