title: Functional analyses of the skin surface of the areola mammae: comparison between healthy adult male and female subjects and between healthy individuals and patients with atopic dermatitis.
abstract: BACKGROUND
  Although the nipple and areola of the breast constitute a unique and prominent area on the chest, so far no study has been done on the functional properties of their skin surfaces.
  
  
  OBJECTIVE
  To study the stratum corneum (SC) covering the areola using noninvasive methods.
  
  
  METHODS
  Eighteen adult healthy subjects comprising nine men and nine women and 18 age- and sex-matched patients with atopic dermatitis (AD), none of whom had visible skin lesions, participated in the study. Transepidermal water loss (TEWL), skin surface hydration and skin surface lipid levels were measured on the areola and adjacent breast skin. The size of the skin surface corneocytes of these skin regions was assessed.
  
  
  RESULTS
  All the healthy subjects showed significantly higher TEWL accompanied by smaller sized corneocytes on the areola than on the adjacent breast skin. Only female subjects revealed a significantly higher skin surface hydration state together with significantly increased skin surface lipid levels on the areola than on the adjacent breast skin. These sex differences were observed even in patients with AD. Comparison between healthy individuals and the patients with AD demonstrated higher TEWL, decreased skin surface hydration state and lower skin surface lipid levels associated with smaller sized corneocytes in the areola in the patients with AD, especially in male patients.
  
  
  CONCLUSIONS
  In adults, the SC barrier function and SC water-binding capacity of the areola were functionally poorer than in the adjacent skin, being covered by smaller sized corneocytes and lower amounts of skin surface lipids, especially in men and in patients with AD.
authors.affiliation: Department of Dermatology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan. kkikuchi@med.tohoku.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Kikuchi
authors.forename: H
authors.initials: H
authors.lastname: Tagami
authors.forename: R
authors.initials: R
authors.lastname: Akaraphanth
authors.forename: S
authors.initials: S
authors.lastname: Aiba
mesh_terms: D000328:Adult; D001834:Body Water; D001940:Breast / Q000503:physiopathology; D016022:Case-Control Studies; D003876:Dermatitis, Atopic / Q000503:physiopathology*; D004817:Epidermis / Q000737:chemistry / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008563:Membrane Lipids / Q000032:analysis*; D009558:Nipples / Q000502:physiology*; D014870:Water Loss, Insensible / Q000502:physiology; D055815:Young Adult
chemical_list: D008563:Membrane Lipids