查看文章

Abstract Background and Aim: Psoriasis is an inflammatory skin disease, which is related to the immune system and is characterized by the rapid growth of skin cells. The aim of this study was to investigate some risk factors in psoriasis and also to check that whether the rate of recurrence is fixed or variable in different seasons by using a time-dependent coefficients rate model. Methods: After reviewing the files of psoriasis patients that had been hospitalized in March 2011 to March 2014 in the dermatology ward of Imam Khomeini Hospital in Tehran, a total of 160 patients who had relapses leading to hospitalization, entered to the study. A rate model with time dependent coefficients by using R software version 3.1 was fitted and risk factors for recurrence were identified. Effect of the season on the recurrence of psoriasis was evaluated. Results: Recurrence rate of psoriasis was 7.2 times higher in winters than in …