Astrid Stumpf

Stress-Induced Allodynia – Evidence of Increased Pain Sensitivity in Healthy Humans and Patients with Chronic Pain after Experimentally Induced Psychosocial Stress

Background Experimental stress has been shown to have analgesic as well as allodynic effect in animals. Despite the obvious negative influence of stress in clinical pain conditions, stress-induced alteration of pain sensitivity has not been tested in humans so far. Therefore, we tested changes of pain sensitivity using an experimental stressor in ten female healthy subjects and 13 female patients with fibromyalgia. Methods Multiple sensory aspects of pain were evaluated in all participants with the help of the quantitative sensory testing protocol before (60 min) and after (10 and 90 min) inducing psychological stress with a standardized psychosocial stress test (“Trier Social Stress Test”). Results Both healthy subjects and patients with fibromyalgia showed stress-induced enhancement of pain sensitivity in response to thermal stimuli. However, only patients showed increased sensitivity in response to pressure pain. Conclusions Our results provide evidence for stress-induced allodynia/hyperalgesia in humans for the first time and suggest differential underlying mechanisms determining response to stressors in healthy subjects and patients suffering from chronic pain. Possible mechanisms of the interplay of stress and mediating factors (e.g. cytokines, cortisol) on pain sensitivity are mentioned. Future studies should help understand better how stress impacts on chronic pain conditions.

Neuropathic itch: diagnosis and management

Chronic pruritus (CP) is a frequent symptom in the general population; in 8% of all patients, it has a neuropathic origin. CP is of neuropathic origin when nerve fiber damage is responsible for the symptom. The damage can be caused by compression or degeneration of the nerve fibers in the skin or extracutaneous in peripheral nerves or the central nervous system. There are significant differences in the pathogenesis and in the clinical presentation of neuropathic CP. Localized neuropathic CP such as brachioradial pruritus or notalgia paresthetica are due to a circumscribed nerve compression and are often limited on the corresponding dermatome. In contrast, generalized neuropathic CP, as in small fiber neuropathies, may be associated with a systemic or metabolic underlying disease. It is not always easy to establish the diagnosis because a variety of diseases can be responsible for this type of CP. The present study shows an overview of possible diseases, diagnostic tools, and the relevant therapy strategies.

Health-Related Quality of Life in Chronic Pruritus: An Analysis Related to Disease Etiology, Clinical Skin Conditions and Itch Intensity.

Background: It is unknown if health-related quality of life (HRQoL) differs between diseases associated with chronic pruritus (CP). Objective: To analyze HRQoL in relation to age, gender, skin lesions (primary vs. scratch-induced secondary) and itch intensity. Methods: Consecutive patients of our itch clinic were assessed with the Dermatology Life Quality Index (DLQI) and visual analogue scale (VAS). Results: In 510 CP patients (282 females; median age, 61.4 years), DLQI scores and VAS values were highly correlated, irrespective of the type of skin lesion. Overall, women had a lower HRQoL compared to men (females: 10.7 ± 6.7, males: 8.9 ± 6.7), but female gender was only associated with worse quality of life in patients <65 years old. Conclusion: HRQoL impairment in CP is highly influenced by pruritus intensity but not to the visible skin lesion or underlying cause. With limitations to item bias, DLQI is a suitable instrument for estimating quality of life impairment by CP.

Sex differences in itch perception and modulation by distraction--an FMRI pilot study in healthy volunteers.

Background Even though itch is a common syndrome of many diseases there is only little knowledge about sex and gender differences in pruritus, especially in central itch perception and modulation. To our knowledge, this is the first fMRI study examining sex differences in perception and its modulation by distraction. Methods Experimental itch was induced by application of histamine (0.1 mM) via microdialysis fibers twice at the left forearm and twice at the left lower leg in 33 healthy volunteers (17 females, 16 males). The brain activation patterns were assessed by fMRI during itch without and with distraction (Stroop task). Between the various conditions, subjects were asked to rate itch intensity, desire to scratch and pain intensity. In a second experiment in 10 of the 33 volunteers histamine was replaced by saline solution to serve as control for the ‘Stroop’ condition. Results Women generally presented higher itch intensities compared to men during itch over the course of the experiment. A more specific analysis revealed higher itch intensities and desire to scratch in women during experimental induced itch that can be reduced by distraction at the lower legs when itch is followed by ‘Stroop’. In contrast, men depicted significant reduction of ‘itch’ by ‘Stroop’ at the forearms. Women depicted higher brain activation of structures responsible for integration of sensory, affective information and motor integration/planning during ‘itch’ and ‘Stroop’ condition when compared to men. No sex differences were seen in the saline control condition. Conclusion Women and men exhibited localisation dependent differences in their itch perception with women presenting higher itch intensities and desire to scratch. Our findings parallel clinical observations of women reporting higher itch intensities depending on itch localisation and suffering more from itch as compared to men.

Body Concept of Patients with Chronic Pruritus in Relation to Scratch Lesions and Psychic Symptoms

Background: There are only a few studies about the body concept of patients with chronic pruritus. We examined the body concept of this group of patients taking into account subgroup-specific differences, limitations of quality of life and the comparison to patients with eating disorders and a healthy control group. Methods: 284 participants with chronic pruritus filled in the Frankfurt Body Concept Scale, the Hospital Anxiety and Depression Scale and the Dermatology Life Quality Index. Statistical analysis was performed using t tests, variance analysis and Pearsons correlations. Results: Patients with chronic pruritus had a more negative body concept than healthy individuals but a less negative concept than patients with eating disorders. Higher levels of depression and anxiety were related to a more negative body image. Conclusion: The body concept of patients with chronic pruritus should be taken into consideration when planning therapy. Whether the body concept changes after successful treatment has to be examined in further studies.

Assessment of Quality of Life in Chronic Pruritus: Relationship Between ItchyQoL and Dermatological Life Quality Index in 1,150 Patients

1https://www.medicaljournals.se/acta/content/abstract/10.2340/00015555-2782 Chronic pruritus (CP) (1) is a bothersome symptom of many diseases (2), and can profoundly reduce quality of life (QoL) (3, 4). In order to evaluate the impact of reduction in QoL in patients with CP independently of their underlying disease, the ItchyQoL questionnaire was developed in 2008 by Desai et al. (5) and translated into German by Krause et al. (6) in 2013 (GerItchyQoL). ItchyQoL is a 22-item questionnaire containing 3 domains: symptoms, functions and emotions. The Dermatological Life Quality Index (DLQI) (7) is currently often used in dermatological patients in general (8), but also in patients with CP (9). ItchyQoL has been developed and validated for all types of CP, while DLQI appears to be valid only in conditions with visible lesions, such as dermatoses or excoriations. Despite the fact that many studies have used DLQI in CP and several studies have used ItchyQoL, the 2 instruments have never been compared. We hypothesized that ItchyQoL (in its German version) more specifically detects symptoms in patients with CP, while the detection of function and emotion might be more similar to DLQI. To examine this hypothesis, we analysed the responses of a large cohort of patients in whom both questionnaires have been applied.

Itch Perception and Skin Reactions as Modulated by Verbal Suggestions: Role of Participant's and Investigator's Sex.

This study investigated sex-specific differences in itch perception and skin reactions, as modulated by verbal suggestions, and the role of the investigators sex. Healthy volunteers (50 males, 50 females), divided into 4 groups, were tested by male and female investigators. Itch was induced via prick testing with sodium chloride and histamine in 4 runs; 2 control conditions (with no exaggerated verbal comments about expected itch) and 2 experimental conditions (with exaggerated verbal comments). After 5 min, wheal and flare reactions were measured and itch intensity was rated by subjects on a numerical rating scale. Exaggerated verbal suggestions resulted in higher itch intensity ratings in the sodium chloride and histamine condition, and higher unpleasantness ratings and a wheal of greater extent in the sodium chloride condition, as well as a flare of greater extent in the histamine condition. The magnitude of the differences between the exaggerated verbal suggestion conditions and respective control conditions was only significantly different between male and female investigators concerning flare size in the histamine condition. There were no differences between male and female participants. Therefore, sex differences may play only a minor role in nocebo-induced itch perception.

Personale Ressourcen in stationärer Fachpsychotherapie - Zusammenhänge und Entwicklung/ Personal resources in inpatient psychotherapy – Relationships and development

OBJECTIVE We examined how personal resources develop during inpatient psychodynamic psychotherapy, their relationship to symptom development, Operationalized Psychodynamic Diagnosis (OPD-2), and sociodemographic aspects. METHODS 483 patients were examined using self-assessment questionnaires (Brief Symptom Inventory (BSI), Hospital Anxiety and Depression Scale (HADS), Inventory of Interpersonal Problems (IIP), Questionnaire of Actual Resource Realization (RES)) as well as the expert ratings Global Assessment of Functioning Scale (GAF), Impairment Score (IS), OPD-2, and the Heidelberg Structural Change Scale (HSCS), both at the beginning and the end of treatment. RESULTS There was a marked improvement in the realization of personal resources during inpatient psychotherapy, which showed significant correlations to the improvement of symptoms. The extent of improvement of resources correlated with the duration of psychotherapy and the assessment of the psychodynamic therapy foci on the HSCS. CONCLUSIONS The results show that personal resources are activated when successfully working on the psychodynamic foci in psychodynamic inpatient treatment, and that this corresponds to an improvement of symptoms.

Cutaneous sensory function is not related to depression and anxiety in patients with chronic pruritus with dysesthetic subqualities.

The objective of this study was to examine the subgroup of patients with chronic pruritus with dysesthetic subqualities for the presence of psychiatric comorbidities and to evaluate whether anxiety and depression make a difference in perception of somatosensory stimuli in quantitative sensory testing (QST). Forty-nine patients underwent routine diagnostics, a standardised QST testing battery, a psychosomatic evaluation for psychic comorbidities and filled out 2 questionnaires: the Patient Health Questionnaire for the assessment of depressive mood and the State Trait Anxiety Inventory. Twenty-seven (55.1%) of the sample had at least one psychiatric comorbid diagnosis. QST parameters were not correlated to anxiety and depression levels. We conclude that psychosomatic evaluation should become part of routine diagnostics of these patients in order to detect and treat psychiatric comorbidity. However, research on somatosensory aspects in these patients seems not to be affected by the levels of anxiety and depression.

Psychosomatic and Psychiatric Disorders and Psychologic Factors in Pruritus

Chronic pruritus (CP) is a bothersome symptom of many different diseases and is often associated with psychosomatic and psychiatric comorbidity. This review gives an overview of psychologic factors that influence the perception and modulation of pruritus based on the well-known biopsychosocial model. Not only psychic comorbidities, such as anxiety and depression, play an important role in the etiology and perception of pruritus, but also internal factors, including personality, mentalization, suggestibility, and external factors, as well as stress. Expectations concerning the intensity of pruritus can also play a role in itch perception that can be modulated by cognitions and behavior of the patient. Obsessive rituals of scratching and skin manipulation with instruments present challenges in the treatment of CP. Initial studies on the efficacy of psychotherapeutic approaches to different problems, such as scratching, comorbidity, or stress-associated itch, show that these might be very useful additions to the multidisciplinary treatment of pruritus.