Even though it has been shown that stress and itch are associated in patients with atopic dermatitis (AD), it remains unclear whether this relationship occurs due to certain coping strategies being activated under stress. Therefore, this study investigates the role of coping as possible mediating factor between stress and itch in 31 patients with AD. Coping and itch were assessed by self-reported measures, while stress was measured both by a validated questionnaire and by a physiological stress marker, the postawakening cortisol. Using a regression and a mediation analysis, this study showed a relationship between perceived stress and itch (corrected R 2 = 0.21), which was fully mediated by negative itch-related cognitions. 62.3% of the variance of itch intensity could be explained by negative itchrelated cognitions. This finding helps to explain the positive effects of cognitive restructuring in the treatment of chronic itch.Key words: atopic dermatitis -coping -itch -postawakening cortisolstress
Accepted for publication 28 October 2014Background Atopic dermatitis is a chronically relapsing skin disease characterized by pruritus, lichenification at certain body sites and other atopic diseases in the patient or his family (1). In most of the patients, itch occurs daily (2,3). Stress is proposed to have an impact on the itch intensity (4). Some studies have shown a link between stress and the AD severity (e.g. 5-8), but only one study has specifically shown a relationship between itch and stress in this patient group (9).Coping can be defined as adaptable thoughts and behaviours intended to manage subjective demanding experiences (10). Some authors found that depressive mood/social anxiety, negative itchrelated cognitions and catastrophization are associated with itch in patients with chronic itch (11,12), but whether the effect of stress on itch is mediated by this kind of coping remains unclear thus far.
Question addressedThis study investigates whether the relationship between stress and itch in patients with AD is mediated by coping.
Experimental designThe data were collected in the context of a greater research project on the effects of stress management in AD (13). Thirty one patients with AD came for two appointments. During the first appointment, patients gave their informed written consent and were instructed on how to collect saliva in the morning on two consecutive days. During the second appointment, perceived stress, coping and itch were assessed. This appointment took place on the second day of saliva collection.
VariablesThe criterion variable, 'itch intensity', was determined using a visual analogue scale (0-10) in the context of assessing the severity of AD [SCORAD (14)].The predictor variable, 'perceived stress', was measured by the Recovery-Stress Questionnaire [REST-Q; short version (15)]. The stress items of the REST-Q were aggregated to 'overall strain'. Postawakening cortisol as a physiological marker of chronic stress (e.g. 16,17) was assessed as further predictor. Patients colle...