title: Davener's dermatosis: a variant of friction hypermelanosis.
abstract: BACKGROUND
  As part of our clinical experience we encountered a group of patients from a specific population with a similar peculiar pigmentation over the lower dorsal spine.
  
  
  OBJECTIVE
  We investigated these patients to see whether we could determine a common origin.
  
  
  METHODS
  Patients meeting the inclusion criteria underwent detailed history and complete physical examination; biopsy specimens from 3 patients were studied.
  
  
  RESULTS
  All 13 patients were full-time male students at Orthodox Jewish Talmudic seminaries (Yeshivas). The lesion consisted of an elongated, vertical, midline, hyperpigmented patch with indistinct borders, which was distributed along the skin overlying the bony protuberances of the inferior thoracic and lumbar vertebrae. It was often unrecognized by the patients. Mean body mass index was lower than that for the general population. Histologic study showed a marked diffuse hyperkeratosis and hyperplastic epidermis with diffuse hyperpigmentation. We attributed the phenomenon to friction from the rigid backrests against the cutaneous surface of the lower back generated by the characteristic swaying activity that traditionally accompanies Torah study or "davening" (praying) and termed it Davener's dermatosis.
  
  
  CONCLUSIONS
  We believe this phenomenon represents a new form of benign friction hypermelanosis. This report highlights the importance of a thorough history in patients presenting with pigmented lesions.
authors.affiliation: Gush Katif Health Center, the Department of Family Medicine, and the Dermatopathology Unit, Institute of Pathology, Soroka Medical Center, Ben Gurion University of the Negev, Faculty of Health Sciences, Beer Sheva, Israel.
authors.forename: S A
authors.initials: SA
authors.lastname: Naimer
authors.forename: A
authors.initials: A
authors.lastname: Trattner
authors.forename: A
authors.initials: A
authors.lastname: Biton
authors.forename: I
authors.initials: I
authors.lastname: Avinoach
authors.forename: D
authors.initials: D
authors.lastname: Vardy
mesh_terms: D000293:Adolescent; D000328:Adult; D001415:Back; D003937:Diagnosis, Differential; D017276:Friction; D006801:Humans; D007557:Israel / Q000453:epidemiology; D007585:Jews; D007599:Judaism; D008297:Male; D008548:Melanosis / Q000175:diagnosis / Q000208:ethnology* / Q000209:etiology*; D012068:Religion and Medicine