title: Lichen planopilaris: Epidemiology and prevalence of subtypes - a retrospective analysis in 104 patients.
abstract: BACKGROUND
  Management of patients with lichen planopilaris (LPP) and frontal fibrosing alopecia (FFA) is rendered difficult as robust epidemiologic data, insights on pathogenesis, associated diseases, possible relevance of concomitant medications or environmental factors are lacking.
  
  
  METHODS
  Retrospective analysis of demography, skin status, concomitant medication and diagnostic procedures were performed on 104 medical records (71 classic LPP, 32 FFA, and one Graham-Little-Piccardi-Lassueur syndrome).
  
  
  RESULTS
  Women were more often affected (distribution F: M classic LPP 4.9: 1; FFA: 31: 1). Compared to LPP patients, patients with FFA were significantly older (p < 0.001), more often postmenopausal, and more frequently on hormone replacement therapy. No other specific associations were identified. An association with lichen planus, other autoimmune diseases, or hepatitis virus infection was found only in individual patients. Clinically, FFA patients were significantly more often reported to have reduced eyebrows (p < 0.005), axillary, and/or pubic hair (p = 0.050).
  
  
  CONCLUSIONS
  The findings obtained from this study, with currently largest LPP/FFA patient cohort in Germany, encouraged us to set up a national FFA patient registry. Prospective data collected from larger numbers of patients with standardized questionnaires will help to assess assumed associations and influencing factors and to develop, in the long-term, recommendations for diagnosis and treatment.
authors.affiliation: Clinical Research Center for Hair and Skin Science, Department of Dermatology and Allergy, Charité-Universitätsmedizin Berlin, Germany.
authors.forename: Johanna
authors.initials: J
authors.lastname: Meinhard
authors.forename: Andrea
authors.initials: A
authors.lastname: Stroux
authors.forename: Lena
authors.initials: L
authors.lastname: Lünnemann
authors.forename: Annika
authors.initials: A
authors.lastname: Vogt
authors.forename: Ulrike
authors.initials: U
authors.lastname: Blume-Peytavi
mesh_terms: D017677:Age Distribution; D015897:Comorbidity; D005260:Female; D005858:Germany / Q000453:epidemiology; D020249:Hormone Replacement Therapy / Q000706:statistics & numerical data*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology*; D008010:Lichen Planus / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology*; D008297:Male; D008659:Metabolic Diseases / Q000453:epidemiology*; D008875:Middle Aged; D015995:Prevalence; D012042:Registries; D012307:Risk Factors; D012536:Scalp Dermatoses / Q000145:classification / Q000453:epidemiology*; D017678:Sex Distribution