title: Applicability of proposed diagnostic criteria of pityriasis rosea: results of a prospective case-control study in India.
abstract: BACKGROUND
  The diagnosis of pityriasis rosea (PR) is generally clinical. Previous studies usually recruited relatively small numbers of patients and control subjects, leading to low power of study results. Systematic reviews and meta-analyses cannot be readily performed, as the inclusion and exclusion criteria of these studies were not uniform. We have previously validated a set of diagnostic criteria (DC) in Chinese patients with PR.
  
  
  OBJECTIVE
  Our aim is to evaluate the validity and applicability of the DC of PR in Indian patients with PR.
  
  
  METHODS
  Prospective unblinded pair-matched case-control study.
  
  
  METHODS
  The setting is a dermatology clinic in India served by one board-certified dermatologist. We recruited all 88 patients seen by us during five years diagnosed to have PR to join our study. For each study subject, we recruited the next patient who consulted us with differential diagnoses of PR as control subjects. We applied the DC of PR on all study and control subjects.
  
  
  RESULTS
  The sensitivity, specificity, positive predictive value, and negative predictive value of the DC were all 100%. Two-tailed Fisher's exact probability test result was 0.036. Φ was 1.00.
  
  
  CONCLUSIONS
  The set of DC can be validly applied to Indian patients with PR.
authors.affiliation: Department of Dermatology, Skin Diseases Center, Nashik, India .
authors.forename: Vijay
authors.initials: V
authors.lastname: Zawar
authors.forename: Antonio
authors.initials: A
authors.lastname: Chuh
keywords: Exclusion criteria; human herpesvirus; inclusion criteria; infectious disease; meta-analysis; power of studies; systematic review; viral exanthem