Temporal case clustering in pityriasis rosea: a regression analysis on 1379 patients in Minnesota, kuwait, and diyarbakir, Turkey

Arch Dermatol. 2005 Jun;141(6):767-71. doi: 10.1001/archderm.141.6.767.


Objective: To detect temporal case clustering in patients with pityriasis rosea in different geographic locations.

Design: Regression analysis of dates on which 1379 patients were diagnosed as having pityriasis rosea in 3 different geographic locations. The control data consisted of dates of diagnosis of patients with psoriasis in the same settings.

Setting: Dermatology clinics in Kuwait, Minnesota, and Diyarbakir, Turkey.Patients Patients with pityriasis rosea and psoriasis seeking care in the clinics.

Results: Three significant positive clusters (P = .005, P =.001, and P =.01, respectively) and 1 significant negative cluster (P<.001) were detected in these series of patients. No cluster was detected in 2 corresponding series of patients with psoriasis in Kuwait and Turkey.

Conclusion: Temporal case clustering exists in pityriasis rosea.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Child
  • Cluster Analysis*
  • Cross-Sectional Studies
  • Evidence-Based Medicine
  • Female
  • Humans
  • Incidence
  • Kuwait / epidemiology
  • Male
  • Middle Aged
  • Minnesota / epidemiology
  • Pityriasis Rosea / diagnosis*
  • Pityriasis Rosea / epidemiology*
  • Probability
  • Regression Analysis
  • Risk Assessment
  • Severity of Illness Index
  • Sex Distribution
  • Turkey / epidemiology