• Registry goals

Registry goals

Objectives of the registry


  • To give insight on the natural course of disease in PP, namely reveal the burden of disease including frequency and severity of flares
  • To reveal the need and efficacy of therapeutic interventions
  • To reveal further genetic causes of PP
  • To describe transcriptional profiles, correlating with subtypes and severity of disease


Primary and secondary endpoints


  • Objective disease activity:
    • Number of flares in the last 2 years (baseline) / since the last visit
    • PGA (depending on PP subtype, further specified as GPP PGA, PPP PGA)
    • PP area and severity score, namely GPP ASI, PPP ASI


  • Quality of Life Scores
    • DLQI
    • EQ-5D
    • WPAI-GH
    • PSS 


  • Patient reported outcomes:
    • Disease activity VAS
    • Pain VAS


The variable of primary interest (corresponding to an endpoint in a clinical trial) is the PGA / IGA severity grade, and as it is an observational study, both the first as well as all other visits are relevant.