title: Nail psoriasis in Germany: epidemiology and burden of disease.
abstract: BACKGROUND
  Although nail psoriasis affects a marked proportion of patients with psoriasis and causes significant psychological stress, only few epidemiological data characterizing patients with nail involvement are available.
  
  
  OBJECTIVE
  To gain robust data on the epidemiology and disease burden of nail psoriasis in Germany.
  
  
  METHODS
  Two nationwide, noninterventional, cross-sectional studies on psoriasis health care were conducted in 2005 and 2007, involving 48 (2005) and 130 (2007) German office-based and clinic-based dermatological centres. Data of n=3531 patients with psoriasis were collected using standardized questionnaires and physical examinations by trained dermatologists. Patients with nail psoriasis were compared with patients without any nail involvement concerning sex, age, disease duration, family history, disease severity, presence of psoriatic arthritis (PsA), health-related quality of life (HRQoL), number of inpatient therapies, and days off work.
  
  
  RESULTS
  Nail psoriasis was diagnosed in 40·9% of the patients; prevalence was 11·2 percentage points higher in men than in women. Patients with nail involvement had a longer disease duration (21·9 vs. 18·1 years), higher disease severity (mean Psoriasis Area and Severity Index 12·7 vs. 9·3), higher frequency of PsA (26·0% vs. 12·7%), stronger impairment of HRQoL (mean Dermatology Life Quality Index 8·9 vs. 7·3), and a 2·5-fold higher rate of inpatient treatments.
  
  
  CONCLUSIONS
  Nail involvement is a relevant manifestation of psoriasis and is associated with a higher disease severity and quality of life impairment. Accordingly, management of psoriasis should include a special focus on nail involvement.
authors.affiliation: CVderm - German Center for Health Services Research in Dermatology, Institute for Health Services Research in Dermatology and Nursing, University Clinics of Hamburg, Martinistrasse 52, 20246 Hamburg, Germany. m.augustin@derma.de
authors.forename: M
authors.initials: M
authors.lastname: Augustin
authors.forename: K
authors.initials: K
authors.lastname: Reich
authors.forename: C
authors.initials: C
authors.lastname: Blome
authors.forename: I
authors.initials: I
authors.lastname: Schäfer
authors.forename: A
authors.initials: A
authors.lastname: Laass
authors.forename: M A
authors.initials: MA
authors.lastname: Radtke
mesh_terms: D000328:Adult; D000368:Aged; D015535:Arthritis, Psoriatic / Q000453:epidemiology; D017281:Cost of Illness; D003430:Cross-Sectional Studies; D005260:Female; D005858:Germany / Q000453:epidemiology; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D009260:Nail Diseases / Q000453:epidemiology*; D015995:Prevalence; D011565:Psoriasis / Q000453:epidemiology*; D011788:Quality of Life; D012720:Severity of Illness Index; D012737:Sex Factors; D018582:Sick Leave