JEADV
DOI: 10.1111/jdv.12763
SHORT REPORT
Non-ablative fractional photothermolysis in treatment of idiopathic guttate hypomelanosis P. Rerknimitr,1,2,* S. Chitvanich,1,2 M. Pongprutthipan,1 R. Panchaprateep,1,2, P. Asawanonda1 1
Division of Dermatology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand Dermatology Unit, Department of Medicine, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand *Correspondence: P. Rerknimitr. E-mail: [email protected]
2
Abstract Background Idiopathic guttate hypomelanosis (IGH) is a common pigmentary disorder affecting a large number of individuals. Many patients seek medical attention due to aesthetic concern. However, no standard treatment is available. Objectives To evaluate the efficacy and side-effects of non-ablative fractional photothermolysis (FP) as a treatment of IGH. Materials and methods A total of 120 lesions from 30 patients with IGH were treated. In each patient, two lesions on the extremities were assigned to treatment group, while lesions from the other side served as control. The treatment was delivered by fractional 1550-nm ytterbium/erbium fibre laser for four times at 4-week intervals. Lesional skin colour was measured by colourimetry. Digital photographs and dermoscopic digital photographs were taken at weeks 0, 4, 8, 12 and 16. In addition, patient satisfaction score and side-effects were recorded. All clinical photographs were evaluated by three experienced dermatologists to determine clinical improvement using a quartile grading scale. Results Colourimetry of the treatment side showed normalization of skin colour at each visit and was statistically significant when compared with control after two treatments (week 8) and continued to decrease until 4 weeks’ follow-up (week 16) (P = 0.047, 0.016 and 0.06 respectively). Physicians’ improvement grading score showed that 83.34% of the lesions in treatment group vs. 18.34% in the control group showed some improvement. The difference was statistically significant (P < 0.05). Common side-effects were erythema and oedema in treatment area, which were mild and transient. No post-inflammatory hyperpigmentation was observed. Conclusion Non-ablative FP appears to be an effective way to treat IGH. The improvements are documented by both objective and subjective measurements. Received: 31 May 2014; Accepted: 5 September 2014
Conflicts of interest None.
Funding sources None.
Introduction Idiopathic guttate hypomelanosis (IGH) is characterized by multiple, smaller than 2 cm, round or oval, hypopigmented to depigmented spots commonly on the exposure parts of the body.1,2 Despite its benignity, some of patients seek treatment due to cosmetic concerns. The treatment options include cryotherapy,3,4 superficial dermabrasion5 and topical retinoids6 with variable results. Our group has reported the efficacy of topical 0.1% tacrolimus ointment and 1% pimecrolimus cream as a treatment of IGH; however, the topical treatments take a long time before the improvement is achieved.7,8
JEADV 2014
Recently, treatment of IGH with fractional carbon dioxide lasers has shown promising results.9,10 Nevertheless, in darkskinned phototype people, fractional carbon dioxide lasers often result in post-inflammatory hyperpigmentation (PIH).11 Hence, non-ablative fractional laser modality which may carry less risk of PIH12,13 seems to be a logical alternative especially as a treatment of IGH in the off-face area such as the extremities.
Material and methods The study was approved by the Institutional Review Board of Faculty of Medicine, Chulalongkorn University. The inclusion criteria were patients with IGH aged more than 40 years old
© 2014 European Academy of Dermatology and Venereology
Rerknimitr et al.
2
with multiple lesions distributed on both sides of the extremities. The diagnosis of IGH was made based on the criteria previously described.1 The exclusion criteria included patients whose IGH lesions had been treated with topical retinoids, topical calcineurin inhibitors, cryotherapy, phototherapy or any laser modalities in the prior 6 months, patients who were pregnant or breast feeding, had history of keloid or hypertrophic scar, were allergic to lidocaine and/or prilocaine or had a history of vitiligo. Two lesions from one side of the body were block randomized to receive fractional photothermolysis (FP) while two lesions from the other side served as control with sham treatment. Topical anaesthetic cream (2.5% lidocaine and 2.5% prilocaine, T.MAN pharma, Bangkok. Thailand) was applied under occlusion for 60 min before each treatment. The treatment was delivered with fractional 1550-nm ytterbium/erbium fibre laser (FINE SCAN 1550TM, TNC Spectronics, Bangkok, Thailand). The parameter setting of the treatment group was energy from 25–30 mJ/cm2; total density was 600 MTZ/cm2, while the control group was treated with energy of 5 mJ/cm2, density 100 MTZ/cm2 which was very low and clinical effects were negligible. After laser treatment, patients were instructed to apply white petrolatum ointment on the treated areas twice daily for 7 days. Each patient received four consecutive treatments at 4-week intervals. A colourimeter (DSM II, Cortex technology, Hadsund, Denmark) was used to measure colour of the lesions and normal skin nearby on both sides. The measurements were taken at baseline, before each treatment (weeks 0, 4, 8, 12) and 4 weeks after the last treatment (week 16). To measure the same lesions at each visit, reference points such as bony prominences were set. The colour was expressed in the L*a*b* system. Pigment is measured on luminosity (L*) scale, from 0 to 100 (black to white). The value of each measurement was a mean of three readings and called ‘absolute lightness index’ (L*I). Relative lightness index (RL*I) was calculated as follows;14
improvement, 1 = minimal, 2 = moderate, 3 = marked, 4 = remarkable). Side-effects of laser treatment, their duration and severity were recorded at each visit. Statistical analysis
The difference of the mean RL*I between the treatment and control groups was analysed by paired t-test. The quartile grading scale and self-assessment score were analysed using Wilcoxon signed-rank test. Statistical significance was considered when P-value 75% improvement
55% 35
48.33%
Number of paƟents
30 25
31.67%
20
23.33% 15
13.33% 10%
10 5
8.33%
6.67%
1.67% 1.67%
0
Figure 3 The patients’ self-assessment score after the last treatment.
Treatment No improvement
Likewise, patients’ self-assessment score also demonstrated that the treatment site showed more improvement than control. The summary of patients’ self-assessment score is depicted in Fig. 3 and the clinical improvement is shown in Fig. 4. A total of 120 lesions of IGH were treated. Side-effects of the treatment included erythema and oedema which were rated as mild and spontaneously improved within 24 hours. Prolonged erythema was observed in four patients (13.34%) and resolved within 3 days. Bronzing occurred in two patients (7%) and subsided in 4–6 weeks. PIH was not seen in our study. In the control group, side-effects were not observed.
Discussion The exact pathogenesis of IGH remains currently unknown. However, ultrastructural studies of IGH lesions reveal a decrease
JEADV 2014
Minimal
Control Moderate
Marked
Remarkable
in number of melanocytes as well as melanin pigment. In addition, abnormal melanocytes with fragmented or no dendrites that contain fewer melanosomes are demonstrated.2,3,15 The underlying mechanism of hypopigmentation observed is believed to be a reduction in number of melanocytes and the presence of dysfunctional ones.2 Fractional photothermolysis has been reported to induce repigmentation in various conditions such as acne scar, hypopigmented scars as well as vitiligo.16,17 However, the mechanisms that trigger this effect are unidentified. After microscopic thermal damages are created by FP, various heat-shock proteins, cytokines and growth factors are secreted as a response in wound healing process.18,19 This probably recruits the adjacent melanocytes into the treated area and melanogenesis might be promoted.16,17 Furthermore, in treating IGH lesions, dysfunctional
© 2014 European Academy of Dermatology and Venereology
Rerknimitr et al.
4
(a)
(b)
(c)
(d)
Figure 4 (a) Baseline, (b) after four consecutive treatments with non-ablative FP, standard digital camera photography (c) baseline, (d) after four consecutive treatments with non-ablative FP, dermoscopy.
melanocytes may be eliminated by FP and replaced by normal ones from neighbouring epidermis.9 Regarding FP technology, two modalities are available. An ablative fractional resurfacing (AFR) such as fractional carbon dioxide laser and non-ablative fractional resurfacing (NAFR) used in this study. AFR offers the ability to ablate the epidermis and penetrate deeper into the dermis compared with its counterpart, consequently favourable outcomes are experienced.11 Nevertheless, in treating dark-skinned individuals especially in the off-face locations, AFR bears a risk of undesired adverse events such as PIH since more tissue injury is generated. Recently, Shin J et al9 and Goldlust M et al10 demonstrate that fractional CO2 lasers provide more than 50% of improvement in 90% of IGH patients at 2 months after a single treatment; however, the rates of PIH are 10% and 12.5%, respectively, and PIH took 3 months to subside. Compared to our study, significant improvement as measured by colourimetry is observed after two treatments and after a completion of four consecutive treatments, 60% of the patients experienced more than 50% improvement on blinded assessment by the dermatologists. It is worth mentioning that by objective measurements, spontaneous improvements did not occur in the sham group. Remarkably, no PIH occurred in our study. Other side-effects found were mild and transient. Therefore, we propose that non-ablative FP can be a good alternative treatment in dark-skinned phototype individuals. Our study is double-blind, randomized and well controlled. Furthermore, the majority of confounding factors are eliminated
JEADV 2014
by left and right comparison within the same patient. In addition, we use a reliable method of objective measurements. Via using RL*I, we minimize the intra-individual difference of the skin colour depending on the site and time of measurement by setting a control. Nevertheless, limitations of our study include a short follow-up period which might not allow us to evaluate the longevity of the treatment response and to exclude PIH as a part of the therapeutic effects. Likewise, histopathological and immunohistochemical study of the pre- and post-treatment lesions would provide more information on the mechanism of repigmentation. However, these were not obtained due to cosmetic and ethical concerns. A further head-to-head study to compare the efficacy and side-effects of AFR and NAFR in treating IGH will be useful. In summary, we demonstrated the efficacy of non-ablative FP as a treatment for IGH. Only a few sessions are needed and clinical outcomes are remarkable. This will be another therapeutic option for IGH patients.
References 1 Shin MK, Jeong KH, Oh IH, Choe BK, Lee MH. Clinical features of idiopathic guttate hypomelanosis in 646 subjects and association with other aspects of photoaging. Int J Dermatol 2011; 50: 798–805. 2 Kim SK, Kim EH, Kang HY, Lee ES, Sohn S, Kim YC. Comprehensive understanding of idiopathic guttate hypomelanosis: clinical and histopathological correlation. Int J Dermatol 2010; 49: 162–166. 3 Ploysangam T, Dee-Ananlap S, Suvanprakorn P. Treatment of idiopathic guttate hypomelanosis with liquid nitrogen: light and electron microscopic studies. J Am Acad Dermatol 1990; 23: 681–684.
© 2014 European Academy of Dermatology and Venereology
Non-ablative FP for IGH
4 Kumarasinghe SP. 3-5 second cryotherapy is effective in idiopathic guttate hypomelanosis. J Dermatol 2004; 31: 437–439. 5 Hexsel DM. Treatment of idiopathic guttate hypomelanosis by localized superficial dermabrasion. Dermatol Surg 1999; 25: 917–918. 6 Pagnoni A, Kligman AM, Sadiq I, Stoudemayer T. Hypopigmented macules of photodamaged skin and their treatment with topical tretinoin. Acta Derm Venereol 1999; 79: 305–310. 7 Rerknimitr P, Disphanurat W, Achariyakul M. Topical tacrolimus significantly promotes repigmentation in idiopathic guttate hypomelanosis: a double-blind, randomized, placebo-controlled study. J Eur Acad Dermatol Venereol 2013; 27: 460–464. 8 Asawanonda P, Sutthipong T, Prejawai N. Pimecrolimus for idiopathic guttate hypomelanosis. J Drugs Dermatol 2010; 9: 238–239. 9 Shin J, Kim M, Park SH, Oh SH. The effect of fractional carbon dioxide lasers on idiopathic guttate hypomelanosis: a preliminary study. J Eur Acad Dermatol Venereol 2013; 27: e243–e246. 10 Goldust M, Mohebbipour A, Mirmohammadi R. Treatment of idiopathic guttate hypomelanosis with fractional carbon dioxide lasers. J Cosmet Laser Ther; doi: 10.3109/14764172.2013.803369. 11 Manuskiatti W, Triwongwaranat D, Varothai S, Eimpunth S, Wanitphakdeedecha R. Efficacy and safety of a carbon-dioxide ablative fractional resurfacing device for treatment of atrophic acne scars in Asians. J Am Acad Dermatol 2010; 63: 274–283.
JEADV 2014
5
12 Rerknimitr P, Pongprutthipan M, Sindhuphak W. Fractional photothermolysis for the treatment of facial wrinkle in Asians. J Med Assoc Thai 2010; 93(Suppl 7): S35–S40. 13 Jih MH, Goldberg LH, Kimyai-Asadi A. Fractional photothermolysis for photoaging of hands. Dermatol Surg 2008; 34: 73–78. 14 Wang CC, Hui CY, Sue YM, Wong WR, Hong HS. Intense pulsed light for the treatment of refractory melasma in Asian persons. Dermatol Surg 2004; 30: 1196–1200. 15 Falabella R, Escobar C, Giraldo N et al. On the pathogenesis of idiopathic guttate hypomelanosis. J Am Acad Dermatol 1987; 16: 35–44. 16 Glaich AS, Rahman Z, Goldberg LH, Friedman PM. Fractional resurfacing for the treatment of hypopigmented scars: a pilot study. Dermatol Surg 2007; 33: 289–294; discussion 293-284. 17 Shin J, Lee JS, Hann SK, Oh SH. Combination treatment by 10 600 nm ablative fractional carbon dioxide laser and narrowband ultraviolet B in refractory nonsegmental vitiligo: a prospective, randomized half-body comparative study. Br J Dermatol 2012; 166: 658–661. 18 Starnes AM, Jou PC, Molitoris JK, Lam M, Baron ED, Garcia-Zuazaga J. Acute effects of fractional laser on photo-aged skin. Dermatol Surg 2012; 38: 51–57. 19 Orringer JS, Rittie L, Baker D, Voorhees JJ, Fisher G. Molecular mechanisms of nonablative fractionated laser resurfacing. Br J Dermatol 2010; 163: 757–768.
© 2014 European Academy of Dermatology and Venereology
DOI: 10.1111/jdv.12763
SHORT REPORT
Non-ablative fractional photothermolysis in treatment of idiopathic guttate hypomelanosis P. Rerknimitr,1,2,* S. Chitvanich,1,2 M. Pongprutthipan,1 R. Panchaprateep,1,2, P. Asawanonda1 1
Division of Dermatology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand Dermatology Unit, Department of Medicine, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand *Correspondence: P. Rerknimitr. E-mail: [email protected]
2
Abstract Background Idiopathic guttate hypomelanosis (IGH) is a common pigmentary disorder affecting a large number of individuals. Many patients seek medical attention due to aesthetic concern. However, no standard treatment is available. Objectives To evaluate the efficacy and side-effects of non-ablative fractional photothermolysis (FP) as a treatment of IGH. Materials and methods A total of 120 lesions from 30 patients with IGH were treated. In each patient, two lesions on the extremities were assigned to treatment group, while lesions from the other side served as control. The treatment was delivered by fractional 1550-nm ytterbium/erbium fibre laser for four times at 4-week intervals. Lesional skin colour was measured by colourimetry. Digital photographs and dermoscopic digital photographs were taken at weeks 0, 4, 8, 12 and 16. In addition, patient satisfaction score and side-effects were recorded. All clinical photographs were evaluated by three experienced dermatologists to determine clinical improvement using a quartile grading scale. Results Colourimetry of the treatment side showed normalization of skin colour at each visit and was statistically significant when compared with control after two treatments (week 8) and continued to decrease until 4 weeks’ follow-up (week 16) (P = 0.047, 0.016 and 0.06 respectively). Physicians’ improvement grading score showed that 83.34% of the lesions in treatment group vs. 18.34% in the control group showed some improvement. The difference was statistically significant (P < 0.05). Common side-effects were erythema and oedema in treatment area, which were mild and transient. No post-inflammatory hyperpigmentation was observed. Conclusion Non-ablative FP appears to be an effective way to treat IGH. The improvements are documented by both objective and subjective measurements. Received: 31 May 2014; Accepted: 5 September 2014
Conflicts of interest None.
Funding sources None.
Introduction Idiopathic guttate hypomelanosis (IGH) is characterized by multiple, smaller than 2 cm, round or oval, hypopigmented to depigmented spots commonly on the exposure parts of the body.1,2 Despite its benignity, some of patients seek treatment due to cosmetic concerns. The treatment options include cryotherapy,3,4 superficial dermabrasion5 and topical retinoids6 with variable results. Our group has reported the efficacy of topical 0.1% tacrolimus ointment and 1% pimecrolimus cream as a treatment of IGH; however, the topical treatments take a long time before the improvement is achieved.7,8
JEADV 2014
Recently, treatment of IGH with fractional carbon dioxide lasers has shown promising results.9,10 Nevertheless, in darkskinned phototype people, fractional carbon dioxide lasers often result in post-inflammatory hyperpigmentation (PIH).11 Hence, non-ablative fractional laser modality which may carry less risk of PIH12,13 seems to be a logical alternative especially as a treatment of IGH in the off-face area such as the extremities.
Material and methods The study was approved by the Institutional Review Board of Faculty of Medicine, Chulalongkorn University. The inclusion criteria were patients with IGH aged more than 40 years old
© 2014 European Academy of Dermatology and Venereology
Rerknimitr et al.
2
with multiple lesions distributed on both sides of the extremities. The diagnosis of IGH was made based on the criteria previously described.1 The exclusion criteria included patients whose IGH lesions had been treated with topical retinoids, topical calcineurin inhibitors, cryotherapy, phototherapy or any laser modalities in the prior 6 months, patients who were pregnant or breast feeding, had history of keloid or hypertrophic scar, were allergic to lidocaine and/or prilocaine or had a history of vitiligo. Two lesions from one side of the body were block randomized to receive fractional photothermolysis (FP) while two lesions from the other side served as control with sham treatment. Topical anaesthetic cream (2.5% lidocaine and 2.5% prilocaine, T.MAN pharma, Bangkok. Thailand) was applied under occlusion for 60 min before each treatment. The treatment was delivered with fractional 1550-nm ytterbium/erbium fibre laser (FINE SCAN 1550TM, TNC Spectronics, Bangkok, Thailand). The parameter setting of the treatment group was energy from 25–30 mJ/cm2; total density was 600 MTZ/cm2, while the control group was treated with energy of 5 mJ/cm2, density 100 MTZ/cm2 which was very low and clinical effects were negligible. After laser treatment, patients were instructed to apply white petrolatum ointment on the treated areas twice daily for 7 days. Each patient received four consecutive treatments at 4-week intervals. A colourimeter (DSM II, Cortex technology, Hadsund, Denmark) was used to measure colour of the lesions and normal skin nearby on both sides. The measurements were taken at baseline, before each treatment (weeks 0, 4, 8, 12) and 4 weeks after the last treatment (week 16). To measure the same lesions at each visit, reference points such as bony prominences were set. The colour was expressed in the L*a*b* system. Pigment is measured on luminosity (L*) scale, from 0 to 100 (black to white). The value of each measurement was a mean of three readings and called ‘absolute lightness index’ (L*I). Relative lightness index (RL*I) was calculated as follows;14
improvement, 1 = minimal, 2 = moderate, 3 = marked, 4 = remarkable). Side-effects of laser treatment, their duration and severity were recorded at each visit. Statistical analysis
The difference of the mean RL*I between the treatment and control groups was analysed by paired t-test. The quartile grading scale and self-assessment score were analysed using Wilcoxon signed-rank test. Statistical significance was considered when P-value 75% improvement
55% 35
48.33%
Number of paƟents
30 25
31.67%
20
23.33% 15
13.33% 10%
10 5
8.33%
6.67%
1.67% 1.67%
0
Figure 3 The patients’ self-assessment score after the last treatment.
Treatment No improvement
Likewise, patients’ self-assessment score also demonstrated that the treatment site showed more improvement than control. The summary of patients’ self-assessment score is depicted in Fig. 3 and the clinical improvement is shown in Fig. 4. A total of 120 lesions of IGH were treated. Side-effects of the treatment included erythema and oedema which were rated as mild and spontaneously improved within 24 hours. Prolonged erythema was observed in four patients (13.34%) and resolved within 3 days. Bronzing occurred in two patients (7%) and subsided in 4–6 weeks. PIH was not seen in our study. In the control group, side-effects were not observed.
Discussion The exact pathogenesis of IGH remains currently unknown. However, ultrastructural studies of IGH lesions reveal a decrease
JEADV 2014
Minimal
Control Moderate
Marked
Remarkable
in number of melanocytes as well as melanin pigment. In addition, abnormal melanocytes with fragmented or no dendrites that contain fewer melanosomes are demonstrated.2,3,15 The underlying mechanism of hypopigmentation observed is believed to be a reduction in number of melanocytes and the presence of dysfunctional ones.2 Fractional photothermolysis has been reported to induce repigmentation in various conditions such as acne scar, hypopigmented scars as well as vitiligo.16,17 However, the mechanisms that trigger this effect are unidentified. After microscopic thermal damages are created by FP, various heat-shock proteins, cytokines and growth factors are secreted as a response in wound healing process.18,19 This probably recruits the adjacent melanocytes into the treated area and melanogenesis might be promoted.16,17 Furthermore, in treating IGH lesions, dysfunctional
© 2014 European Academy of Dermatology and Venereology
Rerknimitr et al.
4
(a)
(b)
(c)
(d)
Figure 4 (a) Baseline, (b) after four consecutive treatments with non-ablative FP, standard digital camera photography (c) baseline, (d) after four consecutive treatments with non-ablative FP, dermoscopy.
melanocytes may be eliminated by FP and replaced by normal ones from neighbouring epidermis.9 Regarding FP technology, two modalities are available. An ablative fractional resurfacing (AFR) such as fractional carbon dioxide laser and non-ablative fractional resurfacing (NAFR) used in this study. AFR offers the ability to ablate the epidermis and penetrate deeper into the dermis compared with its counterpart, consequently favourable outcomes are experienced.11 Nevertheless, in treating dark-skinned individuals especially in the off-face locations, AFR bears a risk of undesired adverse events such as PIH since more tissue injury is generated. Recently, Shin J et al9 and Goldlust M et al10 demonstrate that fractional CO2 lasers provide more than 50% of improvement in 90% of IGH patients at 2 months after a single treatment; however, the rates of PIH are 10% and 12.5%, respectively, and PIH took 3 months to subside. Compared to our study, significant improvement as measured by colourimetry is observed after two treatments and after a completion of four consecutive treatments, 60% of the patients experienced more than 50% improvement on blinded assessment by the dermatologists. It is worth mentioning that by objective measurements, spontaneous improvements did not occur in the sham group. Remarkably, no PIH occurred in our study. Other side-effects found were mild and transient. Therefore, we propose that non-ablative FP can be a good alternative treatment in dark-skinned phototype individuals. Our study is double-blind, randomized and well controlled. Furthermore, the majority of confounding factors are eliminated
JEADV 2014
by left and right comparison within the same patient. In addition, we use a reliable method of objective measurements. Via using RL*I, we minimize the intra-individual difference of the skin colour depending on the site and time of measurement by setting a control. Nevertheless, limitations of our study include a short follow-up period which might not allow us to evaluate the longevity of the treatment response and to exclude PIH as a part of the therapeutic effects. Likewise, histopathological and immunohistochemical study of the pre- and post-treatment lesions would provide more information on the mechanism of repigmentation. However, these were not obtained due to cosmetic and ethical concerns. A further head-to-head study to compare the efficacy and side-effects of AFR and NAFR in treating IGH will be useful. In summary, we demonstrated the efficacy of non-ablative FP as a treatment for IGH. Only a few sessions are needed and clinical outcomes are remarkable. This will be another therapeutic option for IGH patients.
References 1 Shin MK, Jeong KH, Oh IH, Choe BK, Lee MH. Clinical features of idiopathic guttate hypomelanosis in 646 subjects and association with other aspects of photoaging. Int J Dermatol 2011; 50: 798–805. 2 Kim SK, Kim EH, Kang HY, Lee ES, Sohn S, Kim YC. Comprehensive understanding of idiopathic guttate hypomelanosis: clinical and histopathological correlation. Int J Dermatol 2010; 49: 162–166. 3 Ploysangam T, Dee-Ananlap S, Suvanprakorn P. Treatment of idiopathic guttate hypomelanosis with liquid nitrogen: light and electron microscopic studies. J Am Acad Dermatol 1990; 23: 681–684.
© 2014 European Academy of Dermatology and Venereology
Non-ablative FP for IGH
4 Kumarasinghe SP. 3-5 second cryotherapy is effective in idiopathic guttate hypomelanosis. J Dermatol 2004; 31: 437–439. 5 Hexsel DM. Treatment of idiopathic guttate hypomelanosis by localized superficial dermabrasion. Dermatol Surg 1999; 25: 917–918. 6 Pagnoni A, Kligman AM, Sadiq I, Stoudemayer T. Hypopigmented macules of photodamaged skin and their treatment with topical tretinoin. Acta Derm Venereol 1999; 79: 305–310. 7 Rerknimitr P, Disphanurat W, Achariyakul M. Topical tacrolimus significantly promotes repigmentation in idiopathic guttate hypomelanosis: a double-blind, randomized, placebo-controlled study. J Eur Acad Dermatol Venereol 2013; 27: 460–464. 8 Asawanonda P, Sutthipong T, Prejawai N. Pimecrolimus for idiopathic guttate hypomelanosis. J Drugs Dermatol 2010; 9: 238–239. 9 Shin J, Kim M, Park SH, Oh SH. The effect of fractional carbon dioxide lasers on idiopathic guttate hypomelanosis: a preliminary study. J Eur Acad Dermatol Venereol 2013; 27: e243–e246. 10 Goldust M, Mohebbipour A, Mirmohammadi R. Treatment of idiopathic guttate hypomelanosis with fractional carbon dioxide lasers. J Cosmet Laser Ther; doi: 10.3109/14764172.2013.803369. 11 Manuskiatti W, Triwongwaranat D, Varothai S, Eimpunth S, Wanitphakdeedecha R. Efficacy and safety of a carbon-dioxide ablative fractional resurfacing device for treatment of atrophic acne scars in Asians. J Am Acad Dermatol 2010; 63: 274–283.
JEADV 2014
5
12 Rerknimitr P, Pongprutthipan M, Sindhuphak W. Fractional photothermolysis for the treatment of facial wrinkle in Asians. J Med Assoc Thai 2010; 93(Suppl 7): S35–S40. 13 Jih MH, Goldberg LH, Kimyai-Asadi A. Fractional photothermolysis for photoaging of hands. Dermatol Surg 2008; 34: 73–78. 14 Wang CC, Hui CY, Sue YM, Wong WR, Hong HS. Intense pulsed light for the treatment of refractory melasma in Asian persons. Dermatol Surg 2004; 30: 1196–1200. 15 Falabella R, Escobar C, Giraldo N et al. On the pathogenesis of idiopathic guttate hypomelanosis. J Am Acad Dermatol 1987; 16: 35–44. 16 Glaich AS, Rahman Z, Goldberg LH, Friedman PM. Fractional resurfacing for the treatment of hypopigmented scars: a pilot study. Dermatol Surg 2007; 33: 289–294; discussion 293-284. 17 Shin J, Lee JS, Hann SK, Oh SH. Combination treatment by 10 600 nm ablative fractional carbon dioxide laser and narrowband ultraviolet B in refractory nonsegmental vitiligo: a prospective, randomized half-body comparative study. Br J Dermatol 2012; 166: 658–661. 18 Starnes AM, Jou PC, Molitoris JK, Lam M, Baron ED, Garcia-Zuazaga J. Acute effects of fractional laser on photo-aged skin. Dermatol Surg 2012; 38: 51–57. 19 Orringer JS, Rittie L, Baker D, Voorhees JJ, Fisher G. Molecular mechanisms of nonablative fractionated laser resurfacing. Br J Dermatol 2010; 163: 757–768.
© 2014 European Academy of Dermatology and Venereology
