Acta Dermato-Venereologica issue 50:1 98-1CompleteContent | Page 13

32 INVESTIGATIVE REPORT Agreeableness as Predictor of Induced Scratching in Patients with Atopic Dermatitis: A Replication Study Christina SCHUT 1# , Katharina REINISCH 1# , Alexander CLASSEN 1 , Sarah ANDRES 1 , Uwe GIELER 2,3 and Jörg KUPFER 1 1 Institute of Medical Psychology, 2 Clinics for Dermatology and Allergology, and 3 Clinics for Psychosomatic Medicine and Psychotherapy, University of Giessen, Giessen, Germany # These authors contributed equally to this paper and should both be considered first authors. In patients with atopic dermatitis agreeableness and public self-consciousness have previously been shown to be significant predictors of induced scratching, whi- le depression was significantly related to induced itch. This study aimed to replicate these findings. Itch and scratching were induced by videos of crawling insects or skin diseases. Induced itch was measured using a visual analogue scale. Scratching behavior was eva- luated by two raters. Psychological variables were assessed using validated questionnaires. Induced scratching could be predicted significantly by agree­ ableness (corrected R 2  = 15.5% or 38% after exclusion of one outlier): Patients scoring low on agreeableness showed a higher increase in scratch movements than patients scoring high on this scale. No associations between induced scratching/itch and public self-cons- ciousness/depression were found. One clinical im- plication that arises from this study could be to offer patients scoring low on agreeableness certain psycho- logical interventions. Key words: atopic dermatitis; itch; scratching; personality; agreeableness; itch induction. Accepted Aug 16, 2017; Epub ahead of print Aug 17, 2017 Acta Derm Venereol 2018; 98: 32–37. Corr: Christina Schut, Institute of Medical Psychology, Justus-Liebig-Uni- versity, Klinikstrasse 29, DE-35392 Giessen, Germany. E-mail: Christina. [email protected] A topic dermatitis (AD) is a chronic inflammatory skin disease which is characterized by lichenification at certain sites of the body and (other) atopic diseases (asthma bronchiale, rhinitis allergica or AD) in the patient and/or his/her family (1). One of the biggest stressors of this disease is the intense itch which bothers AD patients, especially in the evening and at night (2, 3). In order to decrease itch, patients scratch, which is associated with immunological reactions and a worsening of inflamma- tion (4). Almost every AD patient experiences his/her itch as annoying and unpleasant (3). The itch intensity during a usual itching episode is evaluated as very intense in this patient group (8.3 out of 10 points). Furthermore, itch occurs in 91.4% of the patients at least once a day (3). Many AD patients experience heat sensations and pain in combination with their itch (3, 5). In some older studies, AD patients were shown to have a certain personality structure which was characterized by high neuroticism scores, hostility and the inability to cope doi: 10.2340/00015555-2767 Acta Derm Venereol 2018; 98: 32–37 with anger (6, 7). Furthermore, patients with AD were found to be more anxious and depressive than healthy controls (6–10) and described themselv es as lower in self-efficacy than healthy controls (8). Even though these relationships could be found, Buske-Kirschbaum et al. (11) posit that one should be rather cautious in relating a certain personality profile to the occurrence of AD, because study results are diverse and not every study found a certain personality structure in patients with AD (11). However, personality characteristics and depression seem to be related to the intensity of itch in this patient group (12–14). One study showed that neuroticism was positively associated with the intensity of itch in patients with AD and psoriasis (13). In another study, a positive correlation between self-rated depression and itch in- tensity was found in AD (12). In addition, being more focused on bodily sensations was linked to the intensity of itch in this patient group (14). Even though the cor- relations in these cited studies were rather low, we were surprised by the results of a study which we published 3 years ago (15). In this study, we investigated the re- lationship between induced itch and personality in AD. We found that induced itch and scratching in AD patients were strongly related to certain personality characteris- tics. Induced scratching could be predicted by public self-consciousness and low agreeableness to a very high degree: Patients who report being very concerned about what other people think about them and at the same time describe themselves as rather rude or aggressive and not very agreeable, displayed more induced scratching than patients with the opposite psychological phenotype (corrected R 2 = 0.534). Furthermore, AD patients scoring high on depression reported a higher itch increase than patients who stated they were not very depressive (cor- rected R 2 = 0.175). In contrast, these associations were not found in healthy controls (15). Even though the results of this previous study (15) were interesting, we believe that the findings need to be replicated in a first step in order to draw clinical implications from them in a second step. In a recently published study on the reproducibility of findings in the field of psychology, it has been outlined that 97% of the original articles investigated reported significant results, whereas not even half of the studies aiming to replicate the significant results were able to do so (16). Thus, many published data seem to report incidental findings, which do not justify treatment modifications. From our This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2018 Acta Dermato-Venereologica.