title: Senile gluteal dermatosis: a clinical study of 137 cases.
abstract: BACKGROUND
  Senile gluteal dermatosis (SGD) is a common genital dermatosis but has gained little attention before. A large-scale clinical study of this disease is lacking.
  
  
  METHODS
  We examined 162 consecutive outpatients with gluteal skin diseases of different causes. Fourteen skin biopsies were performed. Patient's age, gender, body mass index (BMI), way of sitting or lying, treatment response, and underlying systemic diseases were recorded.
  
  
  RESULTS
  About 137 (85%) patients could be defined as SGD. These patients, with a mean age of 79.4 ± 40.7 years and a mean BMI of 21.7 ± 10.8, presented with either partial (n = 43, 31%) or full-blown (n = 94, 69%) SGD lesions characterized by the sign of so-called "three corners of a triangle": brownish plaques on the gluteal cleft and each side of the buttocks. Male/female ratio was 130/7. Itching or pain of varying intensity was reported by 50 patients (36%) and 14 patients (10%), respectively. Eighty-six patients (53%) presented with horizontal hyperkeratotic ridges, a characteristic sign of SGD. Most patients spent most of the day sitting but reported no special way of sitting or lying. More than half of patients with SGD claimed no response to topical steroids and/or keratolytics. In comparison with patients with SGD, SGD-free patients were younger (61.3 ± 36 years, P = 0.0005) and heavier (BMI 26.2 ± 15.6, P < 0.0001) but showed no significant difference in the frequency of underlying systemic diseases.
  
  
  CONCLUSIONS
  SGD is a common dermatosis, mostly affecting the thinner elderly. Friction, pressures and long hours sitting seemed to be important factors to trigger this dermatosis.
authors.affiliation: Department of Dermatology, Taipei-Veterans General Hospital, National Defense Medical Center, Taipei, Taiwan; Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Han-Nan
authors.initials: HN
authors.lastname: Liu
authors.forename: Wen-Jen
authors.initials: WJ
authors.lastname: Wang
authors.forename: Chih-Chiang
authors.initials: CC
authors.lastname: Chen
authors.forename: Ding-Dar
authors.initials: DD
authors.lastname: Lee
authors.forename: Yun-Ting
authors.initials: YT
authors.lastname: Chang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D015992:Body Mass Index; D002081:Buttocks / Q000098:blood supply / Q000473:pathology*; D004487:Edema / Q000473:pathology; D005260:Female; D017276:Friction; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture; D011312:Pressure; D012189:Retrospective Studies; D012867:Skin / Q000098:blood supply / Q000473:pathology*; D012871:Skin Diseases / Q000473:pathology*