JEADV
LETTER TO THE EDITOR
Effects of radiofrequency procedure on hypertrophic scar due to burns Editor In burns, several factors act to contribute to the prolonged healing of injuries, often resulting in inflammation, proliferation of fibrous tissue, oedema and hypertrophic and unsightly scarring. The pathophysiology of hypertrophic scar is still not fully elucidated.1 Hypertrophic scars caused by burns are accompanied by pain, functional and aesthetic deficit. These complications usually require surgical intervention, but the outcomes of such interventions are not always satisfactory.2 Among the resources available for the treatment of hypertrophic scars and keloids is radiofrequency (RF), which plays an important role in collagen synthesis.3,4 RF is a form of alternating electric current, which generates heat through the resistance of dermal and subcutaneous tissue.5 This study aimed to evaluate the effects of RF at different temperature ranges on hypertrophic scars from burns. University Ethics Committee approved this study. The skin from a 61-year-old woman who had suffered burns by direct fire in her abdominal region at the age of 2 years who had presented with a hypertrophic scar was studied: normal skin (NS), hypertrophic scar from burns: without treatment (HS), treated with RF bellow (RF ≤ 40) and above 40 °C (RF ≥ 40). After 40 days, samples obtained from skin removed during a reverse abdominoplasty surgery were fixed in Methacarn solution, processed to paraffin and stained with Picro-sirius, as conventional methods. Hypertrophic scars received five sessions of RF for 5 min after skin reached a temperature bellow 37–39 °C or above 40 °C by means of Espectra, a kind of monopolar equipment (Tonedermâ, P = 100 W, F = 0.7 MHz and a 35 mm electrode). Temperature was monitored with an infrared thermometer. Through the reticular dermis, five areas of collagen (birefringence in polarized light) were automatically quantified, by a systematic random sampling around the fields, using the Image Pro-Plus 4.0â software. Percentage area of collagen was analysed using ANOVA and Tukey test with GraphPad Instatâ; P ≤ 0.05 was considered significant.
JEADV 2014
In NS, the reticular dermis showed, as expected, bundles of fibres arranged in several directions (30.05 3.63%), and delicate fibres appeared in the papillary dermis. In HS, fibrosis was seen in the papillary and reticular dermis (30.62 5.92%). The collagen fibres appeared in greater quantity and in thick bundles, when compared with NS. In RF ≤ 40, there was an evident morphological change of collagen organization (29.26 2.18%) compared with HS (P > 0.05), and the amount of collagen fibres was seen as similar to the NS in the reticular dermis (P > 0.05). Also, the papillary dermis had a density of collagen fibres similar to NS. However, RF ≥ 40 showed severe fibrosis (49.44 12.34%), when compared with NS (P < 0.05) and higher collagen fibres than HS, reticular dermis (P < 0.05) and papillary dermis (Fig. 1). Many therapeutic approaches are proposed in search of more conservative treatments to prevent or treat the scar, such as the use of silicone gel and tretinoin cream6, compression, laser therapy, cryotherapy, drug therapy and surgery.7 After a single application of RF and an interval of four weeks in hypertrophic scars and keloids, there were no significant clinical differences and no morphological changes in collagen fibres.8 Our results suggest that RF at an epidermal temperature below 40 °C may stimulate remodelling of collagen fibres, probably due to the effect of heat-induced protein denaturation. RF acts on collagen synthesis, initially by their denaturation, and subsequently, by increased expression of heat shock proteins.3,4 Although this study has been performed using a single subject with hypertrophic scar, our results indicate that it may be possible to recommend RF below 40 °C to cause the remodelling of collagen; moreover, special care must be taken when using RF above 40 °C because it may lead to fibrosis. This research should be considered exploratory in nature. Further studies are needed to better understand the mechanisms leading to collagen remodelling in burn injuries. N.M. Pinheiro,1 P.R. Melo,2 V.O. Crema,1 A.C. Mendoncß a2,* 1
Structural Biology Department, Institute of Natural and Biological Sciences, Federal University of Tri^ angulo Mineiro, 2Physiotherapy ^ngulo Department, Institute of Health Sciences of Federal University of Tria Mineiro, Uberaba, MG, Brazil *Correspondence: A.C. Mendoncßa. E-mail: adrianacm@fisioterapia.uftm. edu.br
© 2014 European Academy of Dermatology and Venereology
Letter to the editor
2
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
Figure 1 Effects of radiofrequency (RF) treatment on hypertrophic scar from burns. Picrosirius stain. Normal skin (a, b); scar (c, d); scar treated with RF bellow 40 °C (e, f); and scar treated with RF above 40 °C (g, h), deep and superficial regions respectively. Bar = 25 lm. (i) Percentages area of collagen fibres in the reticular derm: normal skin, scar, scar treated with RF bellow 40 °C, and scar treated with RF above 40 °C. ANOVA test and Tukey for multiple comparisons test, *P < 0.05.
(i)
References 1 Kamath NV, Ormsby A, Bergfeld WF, House NS. A light microscopic and immunohistochemical evaluation of scars. J Cutan Pathol 2002; 29: 27–32. 2 Kelly AP. Medical and surgical therapies for keloids. Dermatol Ther 2004; 17: 212–218. 3 Hantash BM, Ubeid AA, Chang H, Kafi R, Renton B. Bipolar fractional radiofrequency treatment induces neoelastogenesis and neocollagenesis. Lasers Surg Med 2009; 41: 1–9. 4 Kaplan H, Gat A. Clinical and histopathological results following TriPollar radiofrequency skin treatments. J Cosmet Laser Ther 2009; 11: 78–84. 5 Elsaie ML, Choudhary S, Leiva A, Nouri K. Nonablative radiofrequency for skin rejuvenation. Dermatol Surg 2010; 36: 577–589.
JEADV 2014
6 Kwon SY, Park SD, Park K. Comparative effect of topical silicone gel and topical tretinoin cream for the prevention of hypertrophic scar and keloid formation and the improvement of scars. J Eur Acad Dermatol Venereol 2013; 19. doi: 10.1111/jdv.12242. [Epub ahead of print]. 7 Bloemen MC, van der Veer WM, Ulrich MM, van Zuijlen PP, Niessen FB, Middelkoop E. Prevention and curative management of hypertrophic scar formation. Burns 2009; 35: 463–475. 8 Meshkinpour A, Ghasri P, Pope K et al. Treatment of hypertrophic scars and keloids with a radiofrequency device: a study of collagen effects. Lasers Surg Med 2005; 37: 343–349. DOI: 10.1111/jdv.12388
© 2014 European Academy of Dermatology and Venereology
LETTER TO THE EDITOR
Effects of radiofrequency procedure on hypertrophic scar due to burns Editor In burns, several factors act to contribute to the prolonged healing of injuries, often resulting in inflammation, proliferation of fibrous tissue, oedema and hypertrophic and unsightly scarring. The pathophysiology of hypertrophic scar is still not fully elucidated.1 Hypertrophic scars caused by burns are accompanied by pain, functional and aesthetic deficit. These complications usually require surgical intervention, but the outcomes of such interventions are not always satisfactory.2 Among the resources available for the treatment of hypertrophic scars and keloids is radiofrequency (RF), which plays an important role in collagen synthesis.3,4 RF is a form of alternating electric current, which generates heat through the resistance of dermal and subcutaneous tissue.5 This study aimed to evaluate the effects of RF at different temperature ranges on hypertrophic scars from burns. University Ethics Committee approved this study. The skin from a 61-year-old woman who had suffered burns by direct fire in her abdominal region at the age of 2 years who had presented with a hypertrophic scar was studied: normal skin (NS), hypertrophic scar from burns: without treatment (HS), treated with RF bellow (RF ≤ 40) and above 40 °C (RF ≥ 40). After 40 days, samples obtained from skin removed during a reverse abdominoplasty surgery were fixed in Methacarn solution, processed to paraffin and stained with Picro-sirius, as conventional methods. Hypertrophic scars received five sessions of RF for 5 min after skin reached a temperature bellow 37–39 °C or above 40 °C by means of Espectra, a kind of monopolar equipment (Tonedermâ, P = 100 W, F = 0.7 MHz and a 35 mm electrode). Temperature was monitored with an infrared thermometer. Through the reticular dermis, five areas of collagen (birefringence in polarized light) were automatically quantified, by a systematic random sampling around the fields, using the Image Pro-Plus 4.0â software. Percentage area of collagen was analysed using ANOVA and Tukey test with GraphPad Instatâ; P ≤ 0.05 was considered significant.
JEADV 2014
In NS, the reticular dermis showed, as expected, bundles of fibres arranged in several directions (30.05 3.63%), and delicate fibres appeared in the papillary dermis. In HS, fibrosis was seen in the papillary and reticular dermis (30.62 5.92%). The collagen fibres appeared in greater quantity and in thick bundles, when compared with NS. In RF ≤ 40, there was an evident morphological change of collagen organization (29.26 2.18%) compared with HS (P > 0.05), and the amount of collagen fibres was seen as similar to the NS in the reticular dermis (P > 0.05). Also, the papillary dermis had a density of collagen fibres similar to NS. However, RF ≥ 40 showed severe fibrosis (49.44 12.34%), when compared with NS (P < 0.05) and higher collagen fibres than HS, reticular dermis (P < 0.05) and papillary dermis (Fig. 1). Many therapeutic approaches are proposed in search of more conservative treatments to prevent or treat the scar, such as the use of silicone gel and tretinoin cream6, compression, laser therapy, cryotherapy, drug therapy and surgery.7 After a single application of RF and an interval of four weeks in hypertrophic scars and keloids, there were no significant clinical differences and no morphological changes in collagen fibres.8 Our results suggest that RF at an epidermal temperature below 40 °C may stimulate remodelling of collagen fibres, probably due to the effect of heat-induced protein denaturation. RF acts on collagen synthesis, initially by their denaturation, and subsequently, by increased expression of heat shock proteins.3,4 Although this study has been performed using a single subject with hypertrophic scar, our results indicate that it may be possible to recommend RF below 40 °C to cause the remodelling of collagen; moreover, special care must be taken when using RF above 40 °C because it may lead to fibrosis. This research should be considered exploratory in nature. Further studies are needed to better understand the mechanisms leading to collagen remodelling in burn injuries. N.M. Pinheiro,1 P.R. Melo,2 V.O. Crema,1 A.C. Mendoncß a2,* 1
Structural Biology Department, Institute of Natural and Biological Sciences, Federal University of Tri^ angulo Mineiro, 2Physiotherapy ^ngulo Department, Institute of Health Sciences of Federal University of Tria Mineiro, Uberaba, MG, Brazil *Correspondence: A.C. Mendoncßa. E-mail: adrianacm@fisioterapia.uftm. edu.br
© 2014 European Academy of Dermatology and Venereology
Letter to the editor
2
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
Figure 1 Effects of radiofrequency (RF) treatment on hypertrophic scar from burns. Picrosirius stain. Normal skin (a, b); scar (c, d); scar treated with RF bellow 40 °C (e, f); and scar treated with RF above 40 °C (g, h), deep and superficial regions respectively. Bar = 25 lm. (i) Percentages area of collagen fibres in the reticular derm: normal skin, scar, scar treated with RF bellow 40 °C, and scar treated with RF above 40 °C. ANOVA test and Tukey for multiple comparisons test, *P < 0.05.
(i)
References 1 Kamath NV, Ormsby A, Bergfeld WF, House NS. A light microscopic and immunohistochemical evaluation of scars. J Cutan Pathol 2002; 29: 27–32. 2 Kelly AP. Medical and surgical therapies for keloids. Dermatol Ther 2004; 17: 212–218. 3 Hantash BM, Ubeid AA, Chang H, Kafi R, Renton B. Bipolar fractional radiofrequency treatment induces neoelastogenesis and neocollagenesis. Lasers Surg Med 2009; 41: 1–9. 4 Kaplan H, Gat A. Clinical and histopathological results following TriPollar radiofrequency skin treatments. J Cosmet Laser Ther 2009; 11: 78–84. 5 Elsaie ML, Choudhary S, Leiva A, Nouri K. Nonablative radiofrequency for skin rejuvenation. Dermatol Surg 2010; 36: 577–589.
JEADV 2014
6 Kwon SY, Park SD, Park K. Comparative effect of topical silicone gel and topical tretinoin cream for the prevention of hypertrophic scar and keloid formation and the improvement of scars. J Eur Acad Dermatol Venereol 2013; 19. doi: 10.1111/jdv.12242. [Epub ahead of print]. 7 Bloemen MC, van der Veer WM, Ulrich MM, van Zuijlen PP, Niessen FB, Middelkoop E. Prevention and curative management of hypertrophic scar formation. Burns 2009; 35: 463–475. 8 Meshkinpour A, Ghasri P, Pope K et al. Treatment of hypertrophic scars and keloids with a radiofrequency device: a study of collagen effects. Lasers Surg Med 2005; 37: 343–349. DOI: 10.1111/jdv.12388
© 2014 European Academy of Dermatology and Venereology
