ABSTRACT

Recently, studies on pityriasis rosea (PR) have pointed out an infectious etiology. The effects of environmental factors and seasonal variations of infectious diseases are known. This study aimed to investigate seasonal frequencies of PR in three centers from different cities.

A retrospective investigation was performed in three dermatology departments from different cities, reviewing the files of patients with PR between the years of 2007-2011. Demographic data of patients and initial time of disease were all recorded. Data of climatic elements at the onset of disease were gathered from the City Directorate of Meteorology for each city.Statistical investigations were achieved for comparing climatic elements among cities and seasonal frequencies at the onset of disease.

Medical records of 690 patients (female: 443 and male: 247) enrolled into the study from three centers were obtained. At the onset of the disease, climatic elements showed statistically significant differences among three cities (p<0.01). The most frequent seasonal inicidence was Spring (203/690, 29.4%). The differences of seasonal frequencies at the onset of disease were not significant (p=0.78).

In all of the centers from three cities with stastically different climatic elements; no stastically significant seasonal frequencies of PR were observed. Further investigations with larger series of patients are needed to support the result of this first multi-centric study in Turkey.