title: Itching sensation in psoriatic patients and its relation to body mass index and IL-17 and IL-31 concentrations.
abstract: BACKGROUND
  According to available data, pruritus is a common symptom of psoriasis, however its characteristics and pathogenesis are not clearly understood.
  
  
  OBJECTIVE
  The main aim of this study was to assess itching sensation among patients suffering from psoriasis, including its incidence and severity. All factors triggering and worsening pruritic symptoms were also carefully analyzed. The authors assessed the relationship of itch with body mass index (BMI) and severity of disease. Moreover, serum levels of interleukin 17 (IL-17) and IL-31 were analyzed in relation to Psoriasis Activity and Severity Index, BMI and severity of pruritus.
  
  
  METHODS
  The study group consisted of 60 patients with plaque-type psoriasis. Analysis of impact of pruritus on the quality of life and worsening factors was based on the questionnaire. The severity of pruritus was assessed with the use of two independent scales. Serum IL-17 and IL-31 levels were measured in 30 patients suffering from psoriasis and in 10 healthy controls using immunoassay tests.
  
  
  RESULTS
  88.3% of analyzed patients complained of itch and the most common factor which exacerbated pruritus was stress (39.6%). Pruritus in psoriasis was independent of gender, illness duration and extent of skin lesions. The average intensity of pruritus was assessed as moderate and did not correlate significantly with BMI level, IL-17 and IL-31.
  
  
  CONCLUSIONS
  Since the pathogenesis of pruritus in psoriasis is not fully understood, further investigation in this area needs to be conducted. Pruritus may be considered as a characteristic feature of psoriasis and, besides the skin lesions, should be a target in dermatological treatment to improve patient's quality of life.
authors.affiliation: Department of Dermatology, Poznan University of Medical Sciences, Poznan, Poland. Head of the Department: Prof. Zygmunt Adamski MD, PhD.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Czarnecka-Operacz
authors.affiliation: Department of Dermatology and Venereology, Poznan University of Medical Sciences, Poznan, Poland. Head of the Department: Prof. Ryszard Żaba MD, PhD.
authors.forename: Adriana
authors.initials: A
authors.lastname: Polańska
authors.affiliation: Department of Dermatology, Poznan University of Medical Sciences, Poznan, Poland. Head of the Department: Prof. Zygmunt Adamski MD, PhD.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Klimańska
authors.affiliation: Department of Dermatology, Poznan University of Medical Sciences, Poznan, Poland. Head of the Department: Prof. Zygmunt Adamski MD, PhD.
authors.forename: Ewa
authors.initials: E
authors.lastname: Teresiak-Mikołajczak
authors.affiliation: Department of Computer Science and Statistics, Poznan University of Medical Sciences, Poznan, Poland. Head of the Department: Prof. Jerzy Moczko MD, PhD.
authors.forename: Marta
authors.initials: M
authors.lastname: Molińska-Glura
authors.affiliation: Department of Dermatology, Poznan University of Medical Sciences, Poznan, Poland. Head of the Department: Prof. Zygmunt Adamski MD, PhD.
authors.forename: Zygmunt
authors.initials: Z
authors.lastname: Adamski
authors.affiliation: Department of Dermatology, Poznan University of Medical Sciences, Poznan, Poland. Head of the Department: Prof. Zygmunt Adamski MD, PhD.
authors.forename: Dorota
authors.initials: D
authors.lastname: Jenerowicz
keywords: Psoriasis Activity and Severity Index; body mass index; interleukin 17; interleukin 31; itch; pruritus; psoriasis