title: Epidermal Hyperplasia and Elevated HB-EGF are More Prominent in Retinoid Dermatitis Compared with Irritant Contact Dermatitis Induced by Benzalkonium Chloride.
abstract: BACKGROUND
  'Retinoid dermatitis' is a retinoid-induced irritant contact dermatitis (ICD). The mechanism of retinoid dermatitis may be different from that of other ICDs. However, it remains uncertain how topical retinoid induce ICD.
  
  
  OBJECTIVE
  We compared several aspects of contact dermatitis induced by topical retinol and benzalkonium chloride (BKC) on hairless mice skin.
  
  
  METHODS
  2% retinol or 2.5% BKC was applied to hairless mice and transepidermal water loss (TEWL), ear thickness, histologic and immunohistochemical findings were compared. We also compared mRNA expression of inflammatory cytokines, epidermal differential markers, cyclooxygenases (COXs) and heparin binding epidermal growth factor like growth factor (HB-EGF).
  
  
  RESULTS
  Topical application of 2% retinol and 2.5% BKC increased TEWL and ear thickness in similar intensity. Epidermal hyperplasia was more prominent in retinol treated skin. Proliferating cell nuclear antigen, involucrin and loricrin expression were higher in retinol-treated skin than in BKC-treated skin. Filaggrin, however, was more expressed in BKC-treated skin. The mRNA expression of IL-8, TNF-alpha, COX-2, involucrin, loricrin and filaggrin were increased in both retinol- and BKC-treated skin in similar intensity. HB-EGF was more significantly increased in retinol-treated skin.
  
  
  CONCLUSIONS
  Elevated HB-EGF and epidermal hyperplasia are more prominent features of retinoid dermatitis than in BKC-induced ICD.
authors: Department of Dermatology and Cutaneous Biology Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors: Jung Eun
authors: JE
authors: Lee
authors: Jae Yong
authors: JY
authors: Chang
authors: Sang Eun
authors: SE
authors: Lee
authors: Moon Young
authors: MY
authors: Kim
authors: Jeong Seon
authors: JS
authors: Lee
authors: Min Geol
authors: MG
authors: Lee
authors: Soo-Chan
authors: SC
authors: Kim