Impact of Acute Stress on Itch Sensation and Scratching Behaviour in Patients With Atopic Dermatitis and Healthy Controls

H. Mochizuki; M.J. Lavery; L.A. Nattkemper; C. Albornoz; R. Valdes Rodriguez; C. Stull; L. Weaver; J. Hamsher; K.M. Sanders; Y.H. Chan; G. Yosipovitch

Disclosures

The British Journal of Dermatology. 2019;180(4):821-827. 

In This Article

Abstract and Introduction

Abstract

Background: Patients with atopic dermatitis (AD) often report that stress aggravates their itch. However, no study has investigated if and how acute stress influences itch sensation and scratching behaviour in these patients.

Objectives: We evaluated the impact of acute stress on experimentally induced cowhage itch perception and scratching behaviour in 16 healthy subjects and 15 patients with AD.

Methods: The Trier Social Stress Test (TSST) was used to induce acute stress. The itch sensation, provoked by applying cowhage to the forearms, and off-site scratching behaviour (not directed at the cowhage application site) were compared before and after performing the TSST or the control condition (watching a video of landscape scenes).

Results: In patients with AD, stress induced by TSST caused a significant reduction of cowhage-evoked itch but significantly increased off-site scratching behaviour. Such changes in itch perception and scratching behaviour were not observed in healthy controls. In addition, a significant positive correlation was noted between stress induced by TSST and clinical severity of eczema.

Conclusions: We speculate that psychological stress increases spontaneous scratching in patients with AD, which may enhance the vicious cycle of itching and scratching, resulting in aggravation of the skin eczema. These results provide new insights on the mechanism of acute stress-related exacerbation of itch in patients with AD.

Introduction

Atopic dermatitis (AD) is a chronic cutaneous inflammatory disease characterized by an imbalance of immune function, including T-helper (Th) cell type 2 (Th2) dominance over Th cell type 1 (Th1), deteriorated skin barrier function and severe pruritus. A growing body of evidence has demonstrated that psychological stress is a significant factor that exacerbates itch in patients with AD.[1–7] Stress is highly prevalent in modern society[8–14] and may significantly affect the success of treatment of chronic itch. Thus, it is important to better understand the mechanism of how stress aggravates itch in patients with AD. The majority of research on this matter has been focused on the effect of stress on immune and skin barrier functions, as well as the role of the hypothalamic–pituitary–adrenal (HPA) axis and sympathetic–adrenal–medullary (SAM) axis.[15–20] These studies have suggested that stress may aggravate atopic eczema via the modulations of activities of immune function, skin barrier function, HPA axis and SAM axis, which can lead to aggravation of itch. On the other hand, it is as yet unknown whether acute stress directly augments itch sensation and/or scratching behaviour, which can cause skin damage and subsequent exacerbation of itch in patients with AD. Thus, the aim of this study was to investigate the impact of acute stress on itch and scratching behaviour in patients with AD compared with healthy control subjects.

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....