Ann Dermatol Vol. 23, Suppl. 2, 2011 CASE REPORT Linear Focal Elastosis Following Striae Distensae http://dx.doi.org/10.5021/ad.2011.23.S2.S141 Linear Focal Elastosis Following Striae Distensae: Further Evidence of Keloidal Repair Process in the Pathogenesis of Linear Focal Elastosis Jin Seob Jeong, M.D., Ji Yeoun Lee, M.D., Mi Kyeong Kim, M.D.1, Tae Young Yoon, M.D. Departments of Dermatology and 1Internal Medicine, School of Medicine and Medical Research Institute, Chungbuk National University, Cheongju, Korea Linear focal elastosis (LFE) is a rare dermal elastosis characterized by hypertrophic yellowish linear plaques and increased abnormal elastic tissues in the lumbosacral area. Although the pathogenesis of this disorder remains unknown, it may be associated with keloidal repair process (KRP) of elastic tissues in striae distensae (SD), because there have been some reported cases of LFE accompanied by SD. We herein report a 14-year-old boy with LFE following SD in the lumbar region. Our case supports the hypothesis of KRP in the pathogenesis of LFE. Immunohistochemical study for transforming growth factor-beta (TGF-β) was negative. Therefore, we assume that the pathogenesis of KRP in LFE is different from that of keloid development, which is the TGF- β signaling pathway. (Ann Dermatol 23(S2) S141∼S143, 2011) -Keywords- Keloidal repair process, Linear focal elastosis, Striae dis- tensae, Transforming growth factor-beta Received January 22, 2010, Revised May 13, 2010, Accepted for publication July 14, 2010 Corresponding author: Tae Young Yoon, M.D., Department of Derma- tology, School of Medicine and Medical Research Institute, Chungbuk National University, 52 Naesoodong-ro, Heungdeok-gu, Cheongju 361-763, Korea. Tel: 82-43-269-6369, Fax: 82-43-266-1698, E-mail: tyyoon@chungbuk.ac.kr This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. INTRODUCTION Since Burket et al.1 described three white elderly men with palpable yellow lines on their back and named the disorder, linear focal elastosis (LFE), in 1989, many cases of LFE have been reported. It usually occurs in the lumbosacral area, characterized by hypertrophic yellowish linear bands and an increase of abnormal elastic tissues2. Although the pathogenesis of LFE remains unknown, it may be associated with keloidal repair process (KRP) of elastic tissue in striae distensae (SD), because some cases of LFE have presented with features of SD3-5. Several cases of LFE, including two cases of LFE with SD, have been reported since we first reported two patients with LFE in the Korean dermatologic literature6-8. We herein report a 14-year-old boy with LFE following SD in the same region. Our case supports the hypothesis of KRP in the patho- genesis of LFE. Additionally, in order to elucidate the role of transforming growth factor-beta (TGF-β) in the patho- genesis of LFE, we performed immunohistochemical study for TGF-β. CASE REPORT A 14-year-old Korean boy presented with a 2-year history of asymptomatic multiple horizontal linear lesions on his lumbar area. His familial and personal histories were unremarkable, and he did not take any significant medi- cations such as steroids. He denied any history of trauma on his lumbar area, obesity, rapid growth, and systemic illness. He recalled that the hypertrophic lesions arose from the atrophic bands, and the atrophic bands on the upper back occurred recently. Physical examination revealed several palpable hypertrophic yellowish bands Vol. 23, Suppl. 2, 2011 S141