title: Abnormal keratin expression in circumscribed palmar hypokeratosis.
abstract: BACKGROUND
  Circumscribed palmar or plantar hypokeratosis (CPH) is a rare skin disorder only recently described.
  
  
  OBJECTIVE
  To determine the diagnostic features and to provide insight into the pathogenesis of CPH, with analysis of two new Japanese cases.
  
  
  METHODS
  Dermoscopy, immunohistochemistry, electron microscopy, polymerase chain reaction amplification for human papillomavirus (HPV) DNA and 16S microbial rRNA gene profiling were conducted.
  
  
  RESULTS
  Dermoscopy showed characteristic features using both dry and jelly immersion observation; step-like desquamation and a homogeneous erythema with regularly distributed whitish spots. Immunohistochemistry revealed strong staining with anti-pankeratin antibody (AE1+AE3) and anti-keratin 16 antibody, and decreased expression of keratin 2e. EM revealed a breakage of the corneocytes within their cytoplasm, but structures for cell attachment were intact. HPV and lesion-specific bacteria were not detected.
  
  
  CONCLUSIONS
  The number of cases analyzed was two.
  
  
  CONCLUSIONS
  Hyperproliferative epidermal state along with enhanced corneocyte fragility may account for the unique features in CPH.
authors.affiliation: Department of Dermatology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan. ishiko@sc.itc.keio.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Ishiko
authors.forename: Itaru
authors.initials: I
authors.lastname: Dekio
authors.forename: Atsushi
authors.initials: A
authors.lastname: Fujimoto
authors.forename: Kaori
authors.initials: K
authors.lastname: Kameyama
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Benno
authors.forename: Masayuki
authors.initials: M
authors.lastname: Amagai
authors.forename: Takeji
authors.initials: T
authors.lastname: Nishikawa
mesh_terms: D000368:Aged; D001419:Bacteria / Q000235:genetics; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D006229:Hand Dermatoses / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D053557:Keratin-2 / Q000378:metabolism*; D007633:Keratins / Q000378:metabolism*; D007642:Keratosis / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D008854:Microscopy, Electron; D008875:Middle Aged; D027383:Papillomaviridae / Q000235:genetics; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D013194:Staining and Labeling
chemical_list: D004279:DNA, Viral; D053557:Keratin-2; D012336:RNA, Ribosomal, 16S; D007633:Keratins